1
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Amon A, Moore EE, Henderson HB, Shittu J, Kunz M, Kastamo S, Huotari N, Loukus A, Ott R, Weiss D, McCall SK. Aluminothermic reduction of CeO 2: mechanism of an economical route to aluminum-cerium alloys. MATERIALS HORIZONS 2024; 11:2382-2387. [PMID: 38564229 DOI: 10.1039/d4mh00087k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Cerium oxide is a low-value byproduct of rare-earth mining yet constitutes the largest fraction of the rare earth elements. The reduction of cerium oxide by liquid aluminum is proposed as an energy- and cost-efficient route to produce high-strength Al-Ce alloys. This work investigated the mechanism of a multi-step reduction reaction to facilitate the industrial adaptation of the process. Differential scanning calorimetry in combination with time-resolved synchrotron diffraction data uncovered the rate-limiting reaction step as the origin of the reported temperature dependence of reduction efficiency. This is the first in situ study of a metallothermic reaction mechanism and will serve as guidance for cost- and energy efficient industrial process control.
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Affiliation(s)
- Alfred Amon
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Emily E Moore
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Hunter B Henderson
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Jibril Shittu
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Martin Kunz
- Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA
| | - Shane Kastamo
- Loukus Technologies Inc., 58390 Centennial Number 6 Road, Calumet, MI 49913, USA
| | - Nikolai Huotari
- Loukus Technologies Inc., 58390 Centennial Number 6 Road, Calumet, MI 49913, USA
| | - Adam Loukus
- Loukus Technologies Inc., 58390 Centennial Number 6 Road, Calumet, MI 49913, USA
| | - Ryan Ott
- Ames National Laboratory, 2415 Pammel Dr, Ames, IA, 50011, USA
| | - David Weiss
- Loukus Technologies Inc., 58390 Centennial Number 6 Road, Calumet, MI 49913, USA
| | - Scott K McCall
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
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2
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Bischoff B, Bekheet MF, Dal Molin E, Praetz S, Kanngießer B, Schomäcker R, Etter M, Jeppesen HS, Tayal A, Gurlo A, Gili A. In situ/operando plug-flow fixed-bed cell for synchrotron PXRD and XAFS investigations at high temperature, pressure, controlled gas atmosphere and ultra-fast heating. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:77-84. [PMID: 38010796 PMCID: PMC10833430 DOI: 10.1107/s1600577523009591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/02/2023] [Indexed: 11/29/2023]
Abstract
A plug-flow fixed-bed cell for synchrotron powder X-ray diffraction (PXRD) and X-ray absorption fine structure (XAFS) idoneous for the study of heterogeneous catalysts at high temperature, pressure and under gas flow is designed, constructed and demonstrated. The operating conditions up to 1000°C and 50 bar are ensured by a set of mass flow controllers, pressure regulators and two infra-red lamps that constitute a robust and ultra-fast heating and cooling method. The performance of the system and cell for carbon dioxide hydrogenation reactions under specified temperatures, gas flows and pressures is demonstrated both for PXRD and XAFS at the P02.1 (PXRD) and the P64 (XAFS) beamlines of the Deutsches Elektronen-Synchrotron (DESY).
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Affiliation(s)
- Benjamin Bischoff
- Technische Universität Berlin, Faculty III Process Sciences, Institute of Materials Science and Technology, Chair of Advanced Ceramic Materials, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Maged F. Bekheet
- Technische Universität Berlin, Faculty III Process Sciences, Institute of Materials Science and Technology, Chair of Advanced Ceramic Materials, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Emiliano Dal Molin
- Technische Universität Berlin, Faculty III Process Sciences, Institute of Materials Science and Technology, Chair of Advanced Ceramic Materials, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Sebastian Praetz
- Technische Universität Berlin, Faculty III Process Sciences, Institute for Optic and Atomic Physics, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Birgit Kanngießer
- Technische Universität Berlin, Faculty III Process Sciences, Institute for Optic and Atomic Physics, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Reinhard Schomäcker
- Technische Universität Berlin, Faculty II Mathematik und Naturwissenschaften, Institut für Chemie, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Martin Etter
- Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - Henrik S. Jeppesen
- Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - Akhil Tayal
- Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - Aleksander Gurlo
- Technische Universität Berlin, Faculty III Process Sciences, Institute of Materials Science and Technology, Chair of Advanced Ceramic Materials, Straße des 17 Juni 135, 10623 Berlin, Germany
| | - Albert Gili
- Technische Universität Berlin, Faculty II Mathematik und Naturwissenschaften, Institut für Chemie, Straße des 17 Juni 135, 10623 Berlin, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany
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3
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Kraka E, Antonio JJ, Freindorf M. Reaction mechanism - explored with the unified reaction valley approach. Chem Commun (Camb) 2023; 59:7151-7165. [PMID: 37233449 DOI: 10.1039/d3cc01576a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
One of the ultimate goals of chemistry is to understand and manipulate chemical reactions, which implies the ability to monitor the reaction and its underlying mechanism at an atomic scale. In this article, we introduce the Unified Reaction Valley Approach (URVA) as a tool for elucidating reaction mechanisms, complementing existing computational procedures. URVA combines the concept of the potential energy surface with vibrational spectroscopy and describes a chemical reaction via the reaction path and the surrounding reaction valley traced out by the reacting species on the potential energy surface on their way from the entrance to the exit channel, where the products are located. The key feature of URVA is the focus on the curving of the reaction path. Moving along the reaction path, any electronic structure change of the reacting species is registered by a change in the normal vibrational modes spanning the reaction valley and their coupling with the path, which recovers the curvature of the reaction path. This leads to a unique curvature profile for each chemical reaction, with curvature minima reflecting minimal change and curvature maxima indicating the location of important chemical events such as bond breaking/formation, charge polarization and transfer, rehybridization, etc. A decomposition of the path curvature into internal coordinate components or other coordinates of relevance for the reaction under consideration, provides comprehensive insight into the origin of the chemical changes taking place. After giving an overview of current experimental and computational efforts to gain insight into the mechanism of a chemical reaction and presenting the theoretical background of URVA, we illustrate how URVA works for three diverse processes, (i) [1,3] hydrogen transfer reactions; (ii) α-keto-amino inhibitor for SARS-CoV-2 Mpro; (iii) Rh-catalyzed cyanation. We hope that this article will inspire our computational colleagues to add URVA to their repertoire and will serve as an incubator for new reaction mechanisms to be studied in collaboration with our experimental experts in the field.
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Affiliation(s)
- Elfi Kraka
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX 75275-0314, USA.
| | - Juliana J Antonio
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX 75275-0314, USA.
| | - Marek Freindorf
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX 75275-0314, USA.
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4
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Cao P, Tang P, Bekheet MF, Du H, Yang L, Haug L, Gili A, Bischoff B, Gurlo A, Kunz M, Dunin-Borkowski RE, Penner S, Heggen M. Atomic-Scale Insights into Nickel Exsolution on LaNiO 3 Catalysts via In Situ Electron Microscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:786-796. [PMID: 35059098 PMCID: PMC8762657 DOI: 10.1021/acs.jpcc.1c09257] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Using a combination of in situ bulk and surface characterization techniques, we provide atomic-scale insight into the complex surface and bulk dynamics of a LaNiO3 perovskite material during heating in vacuo. Driven by the outstanding activity LaNiO3 in the methane dry reforming reaction (DRM), attributable to the decomposition of LaNiO3 during DRM operation into a Ni//La2O3 composite, we reveal the Ni exsolution dynamics both on a local and global scale by in situ electron microscopy, in situ X-ray diffraction and in situ X-ray photoelectron spectroscopy. To reduce the complexity and disentangle thermal from self-activation and reaction-induced effects, we embarked on a heating experiment in vacuo under comparable experimental conditions in all methods. Associated with the Ni exsolution, the remaining perovskite grains suffer a drastic shrinkage of the grain volume and compression of the structure. Ni particles mainly evolve at grain boundaries and stacking faults. Sophisticated structure analysis of the elemental composition by electron-energy loss mapping allows us to disentangle the distribution of the different structures resulting from LaNiO3 decomposition on a local scale. Important for explaining the DRM activity, our results indicate that most of the Ni moieties are oxidized and that the formation of NiO occurs preferentially at grain edges, resulting from the reaction of the exsolved Ni particles with oxygen released from the perovskite lattice during decomposition via a spillover process from the perovskite to the Ni particles. Correlating electron microscopy and X-ray diffraction data allows us to establish a sequential two-step process in the decomposition of LaNiO3 via a Ruddlesden-Popper La2NiO4 intermediate structure. Exemplified for the archetypical LaNiO3 perovskite material, our results underscore the importance of focusing on both surface and bulk characterization for a thorough understanding of the catalyst dynamics and set the stage for a generalized concept in the understanding of state-of-the art catalyst materials on an atomic level.
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Affiliation(s)
- Pengfei Cao
- School of Chemical
Engineering and Technology, Xi’an
Jiaotong University, Xi’an 710049, China
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
| | - Pengyi Tang
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
- State Key Laboratory
of Information Functional Materials, 2020 X-Lab, ShangHai Institute
of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, P. R. China
| | - Maged F. Bekheet
- Chair of Advanced
Ceramic Materials, Institut für Werkstoffwissenschaften und
-technologien, Technical University Berlin, Hardenbergstrasse 40, D-10623 Berlin, Germany
| | - Hongchu Du
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
| | - Luyan Yang
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
| | - Leander Haug
- Department of Physical Chemistry, University
of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Albert Gili
- Chair of Advanced
Ceramic Materials, Institut für Werkstoffwissenschaften und
-technologien, Technical University Berlin, Hardenbergstrasse 40, D-10623 Berlin, Germany
| | - Benjamin Bischoff
- Chair of Advanced
Ceramic Materials, Institut für Werkstoffwissenschaften und
-technologien, Technical University Berlin, Hardenbergstrasse 40, D-10623 Berlin, Germany
| | - Aleksander Gurlo
- Chair of Advanced
Ceramic Materials, Institut für Werkstoffwissenschaften und
-technologien, Technical University Berlin, Hardenbergstrasse 40, D-10623 Berlin, Germany
| | - Martin Kunz
- Advanced Light Source, Lawrence
Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Rafal E. Dunin-Borkowski
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
| | - Simon Penner
- Department of Physical Chemistry, University
of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Marc Heggen
- Ernst Ruska-Centre
for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse 1, D-52428 Jülich, Germany
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5
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Delir Kheyrollahi Nezhad P, Bekheet MF, Bonmassar N, Gili A, Kamutzki F, Gurlo A, Doran A, Schwarz S, Bernardi J, Praetz S, Niaei A, Farzi A, Penner S. Elucidating the role of earth alkaline doping in perovskite-based methane dry reforming catalysts. Catal Sci Technol 2022; 12:1229-1244. [PMID: 35310768 PMCID: PMC8859525 DOI: 10.1039/d1cy02044g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/05/2022] [Indexed: 11/21/2022]
Abstract
To elucidate the role of earth alkaline doping in perovskite-based dry reforming of methane (DRM) catalysts, we embarked on a comparative and exemplary study of a Ni-based Sm perovskite with and without Sr doping. While the Sr-doped material appears as a structure-pure Sm1.5Sr0.5NiO4 Ruddlesden Popper structure, the undoped material is a NiO/monoclinic Sm2O3 composite. Hydrogen pre-reduction or direct activation in the DRM mixture in all cases yields either active Ni/Sm2O3 or Ni/Sm2O3/SrCO3 materials, with albeit different short-term stability and deactivation behavior. The much smaller Ni particle size after hydrogen reduction of Sm1.5Sr0.5NiO4, and of generally all undoped materials stabilizes the short and long-term DRM activity. Carbon dioxide reactivity manifests itself in the direct formation of SrCO3 in the case of Sm1.5Sr0.5NiO4, which is dominant at high temperatures. For Sm1.5Sr0.5NiO4, the CO : H2 ratio exceeds 1 at these temperatures, which is attributed to faster direct carbon dioxide conversion to SrCO3 without catalytic DRM reactivity. As no Sm2O2CO3 surface or bulk phase as a result of carbon dioxide activation was observed for any material – in contrast to La2O2CO3 – we suggest that oxy-carbonate formation plays only a minor role for DRM reactivity. Rather, we identify surface graphitic carbon as the potentially reactive intermediate. Graphitic carbon has already been shown as a crucial reaction intermediate in metal-oxide DRM catalysts and appears both for Sm1.5Sr0.5NiO4 and NiO/monoclinic Sm2O3 after reaction as crystalline structure. It is significantly more pronounced for the latter due to the higher amount of oxygen-deficient monoclinic Sm2O3 facilitating carbon dioxide activation. Despite the often reported beneficial role of earth alkaline dopants in DRM catalysis, we show that the situation is more complex. In our studies, the detrimental role of earth alkaline doping manifests itself in the exclusive formation of the sole stable carbonated species and a general destabilization of the Ni/monoclinic Sm2O3 interface by favoring Ni particle sintering. To elucidate the role of earth alkaline doping in perovskite-based dry reforming of methane (DRM) catalysts, we embarked on a comparative and exemplary study of a Ni-based Sm perovskite with and without Sr doping.![]()
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Affiliation(s)
- Parastoo Delir Kheyrollahi Nezhad
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, Iran
| | - Maged F. Bekheet
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Nicolas Bonmassar
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Albert Gili
- Institut für Chemie, Technische Universität Berlin, Sekretariat TC 8, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Franz Kamutzki
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley, California 94720, USA
| | - Sabine Schwarz
- University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Johannes Bernardi
- University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Sebastian Praetz
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Aligholi Niaei
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, Iran
| | - Ali Farzi
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, Iran
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
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6
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Penner S. How the in situ monitoring of bulk crystalline phases during catalyst activation results in a better understanding of heterogeneous catalysis. CrystEngComm 2021; 23:6470-6480. [PMID: 34602861 PMCID: PMC8474056 DOI: 10.1039/d1ce00817j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/06/2021] [Indexed: 12/03/2022]
Abstract
The present Highlight article shows the importance of the in situ monitoring of bulk crystalline compounds for a more thorough understanding of heterogeneous catalysts at the intersection of catalysis, materials science, crystallography and inorganic chemistry. Although catalytic action is widely regarded as a purely surface-bound phenomenon, there is increasing evidence that bulk processes can detrimentally or beneficially influence the catalytic properties of various material classes. Such bulk processes include polymorphic transformations, formation of oxygen-deficient structures, transient phases and the formation of a metal-oxide composite. The monitoring of these processes and the subsequent establishment of structure-property relationships are most effective if carried out in situ under real operation conditions. By focusing on synchrotron-based in situ X-ray diffraction as the perfect tool to follow the evolution of crystalline species, we exemplify the strength of the concept with five examples from various areas of catalytic research. As catalyst activation studies are increasingly becoming a hot topic in heterogeneous catalysis, the (self-)activation of oxide- and intermetallic compound-based materials during methanol steam and methane dry reforming is highlighted. The perovskite LaNiO3 is selected as an example to show the complex structural dynamics before and during methane dry reforming, which is only revealed upon monitoring all intermediate crystalline species in the transformation from LaNiO3 into Ni/La2O3/La2O2CO3. ZrO2-based materials form the second group, indicating the in situ decomposition of the intermetallic compound Cu51Zr14 into an epitaxially stabilized Cu/tetragonal ZrO2 composite during methanol steam reforming, the stability of a ZrO0.31C0.69 oxycarbide and the gas-phase dependence of the tetragonal-to-monoclinic ZrO2 polymorphic transformation. The latter is the key parameter to the catalytic understanding of ZrO2 and is only appreciated in full detail once it is possible to follow the individual steps of the transformation between the crystalline polymorphic structures. A selected example is devoted to how the monitoring of crystalline reactive carbon during methane dry reforming operation aids in the mechanistic understanding of a Ni/MnO catalyst. The most important aspect is the strict use of in situ monitoring of the structural changes occurring during (self-)activation to establish meaningful structure-property relationships allowing conclusions beyond isolated surface chemical aspects.
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Affiliation(s)
- Simon Penner
- Institute of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +4351250758003
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7
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Ploner K, Doran A, Kunz M, Gili A, Gurlo A, Köwitsch N, Armbrüster M, Bernardi J, Watschinger M, Penner S. Steering the methanol steam reforming reactivity of intermetallic Cu-In compounds by redox activation: stability vs. formation of an intermetallic compound-oxide interface. Catal Sci Technol 2021; 11:5518-5533. [PMID: 34457240 PMCID: PMC8365629 DOI: 10.1039/d1cy00913c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022]
Abstract
To compare the inherent methanol steam reforming properties of intermetallic compounds and a corresponding intermetallic compound–oxide interface, we selected the Cu–In system as a model to correlate the stability limits, self-activation and redox activation properties with the catalytic performance. Three distinct intermetallic Cu–In compounds – Cu7In3, Cu2In and Cu11In9 – were studied both in an untreated and redox-activated state resulting from alternating oxidation–reduction cycles. The stability of all studied intermetallic compounds during methanol steam reforming (MSR) operation is essentially independent of the initial stoichiometry and all accordingly resist substantial structural changes. The inherent activity under batch MSR conditions is highest for Cu2In, corroborating the results of a Cu2In/In2O3 sample accessed through reactive metal–support interaction. Under flow MSR operation, Cu7In3 displays considerable deactivation, while Cu2In and Cu11In9 feature stable performance at simultaneously high CO2 selectivity. The missing significant self-activation is most evident in the operando thermogravimetric experiments, where no oxidation is detected for any of the intermetallic compounds. In situ X-ray diffraction allowed us to monitor the partial decomposition and redox activation of the Cu–In intermetallic compounds into Cu0.9In0.1/In2O3 (from Cu7In3), Cu7In3/In2O3 (from Cu2In) and Cu7In3/Cu0.9In0.1/In2O3 (from Cu11In9) interfaces with superior MSR performance compared to the untreated samples. Although the catalytic profiles appear surprisingly similar, the latter interface with the highest indium content exhibits the least deactivation, which we explain by formation of stabilizing In2O3 patches under MSR conditions. To compare the properties of intermetallic compounds and intermetallic compound–oxide interfaces, Cu–In was used as a model to correlate stability limits, self-activation and redox activation with the inherent methanol steam reforming performance.![]()
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Affiliation(s)
- Kevin Ploner
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +4351250758003
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Martin Kunz
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Albert Gili
- Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und - Technologien, Technical University Berlin Hardenbergstr. 40 D-10623 Berlin Germany.,Institute of Chemistry, Technical University Berlin Sekretariat TC 8, Straße des 17. Juni 124 D-10623 Berlin Germany
| | - Aleksander Gurlo
- Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und - Technologien, Technical University Berlin Hardenbergstr. 40 D-10623 Berlin Germany
| | - Nicolas Köwitsch
- Institute of Chemistry, Materials for Innovative Energy Concepts, Technical University Chemnitz Straße der Nationen 62 D-09111 Chemnitz Germany
| | - Marc Armbrüster
- Institute of Chemistry, Materials for Innovative Energy Concepts, Technical University Chemnitz Straße der Nationen 62 D-09111 Chemnitz Germany
| | - Johannes Bernardi
- University Service Centre for Transmission Electron Microscopy, TU Wien Wiedner Hauptstr. 8-10 A-1040 Vienna Austria
| | - Maximilian Watschinger
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +4351250758003
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +4351250758003
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8
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Ploner K, Delir Kheyrollahi Nezhad P, Gili A, Kamutzki F, Gurlo A, Doran A, Cao P, Heggen M, Köwitsch N, Armbrüster M, Watschinger M, Klötzer B, Penner S. The sol-gel autocombustion as a route towards highly CO 2-selective, active and long-term stable Cu/ZrO 2 methanol steam reforming catalysts. MATERIALS CHEMISTRY FRONTIERS 2021; 5:5093-5105. [PMID: 34262777 PMCID: PMC8238116 DOI: 10.1039/d1qm00641j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/20/2021] [Indexed: 06/13/2023]
Abstract
The adaption of the sol-gel autocombustion method to the Cu/ZrO2 system opens new pathways for the specific optimisation of the activity, long-term stability and CO2 selectivity of methanol steam reforming (MSR) catalysts. Calcination of the same post-combustion precursor at 400 °C, 600 °C or 800 °C allows accessing Cu/ZrO2 interfaces of metallic Cu with either amorphous, tetragonal or monoclinic ZrO2, influencing the CO2 selectivity and the MSR activity distinctly different. While the CO2 selectivity is less affected, the impact of the post-combustion calcination temperature on the Cu and ZrO2 catalyst morphology is more pronounced. A porous and largely amorphous ZrO2 structure in the sample, characteristic for sol-gel autocombustion processes, is obtained at 400 °C. This directly translates into superior activity and long-term stability in MSR compared to Cu/tetragonal ZrO2 and Cu/monoclinic ZrO2 obtained by calcination at 600 °C and 800 °C. The morphology of the latter Cu/ZrO2 catalysts consists of much larger, agglomerated and non-porous crystalline particles. Based on aberration-corrected electron microscopy, we attribute the beneficial catalytic properties of the Cu/amorphous ZrO2 material partially to the enhanced sintering resistance of copper particles provided by the porous support morphology.
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Affiliation(s)
- Kevin Ploner
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +43 51250758003
| | | | - Albert Gili
- Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technical University Berlin Hardenbergstr. 40 D-10623 Berlin Germany
- Institute of Chemistry, Technical University Berlin Sekretariat TC 8 Straße des 17. Juni 124 D-10623 Berlin Germany
| | - Franz Kamutzki
- Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technical University Berlin Hardenbergstr. 40 D-10623 Berlin Germany
| | - Aleksander Gurlo
- Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technical University Berlin Hardenbergstr. 40 D-10623 Berlin Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Pengfei Cao
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH Leo-Brandt-Str. 1 D-52428 Jülich Germany
| | - Marc Heggen
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH Leo-Brandt-Str. 1 D-52428 Jülich Germany
| | - Nicolas Köwitsch
- Faculty of Natural Sciences, Institute of Chemistry, Materials for Innovative Energy Concepts, Technical University Chemnitz Straße der Nationen 62 D-09111 Chemnitz Germany
| | - Marc Armbrüster
- Faculty of Natural Sciences, Institute of Chemistry, Materials for Innovative Energy Concepts, Technical University Chemnitz Straße der Nationen 62 D-09111 Chemnitz Germany
| | - Maximilian Watschinger
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +43 51250758003
| | - Bernhard Klötzer
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +43 51250758003
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +43 51250758003
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Klaes J, Rothweiler P, Bornmann B, Wagner R, Lützenkirchen-Hecht D. High-temperature treatments of niobium under high vacuum, dilute air- and nitrogen-atmospheres as investigated by in situ X-ray absorption spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:266-277. [PMID: 33399577 PMCID: PMC7842222 DOI: 10.1107/s1600577520013557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Niobium metal foils were heat-treated at 900°C under different conditions and in situ investigated with time-resolved X-ray absorption fine-structure (EXAFS and XANES) measurements. The present study aims to mimic the conditions usually applied for heat treatments of Nb materials used for superconducting radiofrequency cavities, in order to better understand the evolving processes during vacuum annealing as well as for heat treatments in controlled dilute gases. Annealing in vacuum in a commercially available cell showed a substantial amount of oxidation, so that a designated new cell was designed and realized, allowing treatments under clean high-vacuum conditions as well as under well controllable gas atmospheres. The experiments performed under vacuum demonstrated that the original structure of the Nb foils is preserved, while a detailed evaluation of the X-ray absorption fine-structure data acquired during treatments in dilute air atmospheres (10-5 mbar to 10-3 mbar) revealed a linear oxidation with the time of the treatment, and an oxidation rate proportional to the oxygen (air) pressure. The structure of the oxide appears to be very similar to that of polycrystalline NbO. The cell also permits controlled exposures to other reactive gases at elevated temperatures; here the Nb foils were exposed to dilute nitrogen atmospheres after a pre-conditioning of the studied Nb material for one hour under high-vacuum conditions, in order to imitate typical conditions used for nitrogen doping of cavity materials. Clear structural changes induced by the N2 exposure were found; however, no evidence for the formation of niobium nitride could be derived from the EXAFS and XANES experiments. The presented results establish the feasibility to study the structural changes of the Nb materials in situ during heat treatments in reactive gases with temporal resolution, which are important to better understand the underlaying mechanisms and the dynamics of phase formation during those heat treatments in more detail.
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Affiliation(s)
- Jonas Klaes
- Fakultät 4 – Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gauß-Straße 20, 42097 Wuppertal, Germany
| | - Patrick Rothweiler
- Fakultät 4 – Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gauß-Straße 20, 42097 Wuppertal, Germany
| | - Benjamin Bornmann
- Fakultät 4 – Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gauß-Straße 20, 42097 Wuppertal, Germany
| | - Ralph Wagner
- Fakultät 4 – Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gauß-Straße 20, 42097 Wuppertal, Germany
| | - Dirk Lützenkirchen-Hecht
- Fakultät 4 – Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gauß-Straße 20, 42097 Wuppertal, Germany
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10
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Bekheet MF, Delir Kheyrollahi Nezhad P, Bonmassar N, Schlicker L, Gili A, Praetz S, Gurlo A, Doran A, Gao Y, Heggen M, Niaei A, Farzi A, Schwarz S, Bernardi J, Klötzer B, Penner S. Steering the Methane Dry Reforming Reactivity of Ni/La 2O 3 Catalysts by Controlled In Situ Decomposition of Doped La 2NiO 4 Precursor Structures. ACS Catal 2021; 11:43-59. [PMID: 33425477 PMCID: PMC7783868 DOI: 10.1021/acscatal.0c04290] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Indexed: 11/28/2022]
Abstract
The influence of A- and/or B-site doping of Ruddlesden-Popper perovskite materials on the crystal structure, stability, and dry reforming of methane (DRM) reactivity of specific A2BO4 phases (A = La, Ba; B = Cu, Ni) has been evaluated by a combination of catalytic experiments, in situ X-ray diffraction, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and aberration-corrected electron microscopy. At room temperature, B-site doping of La2NiO4 with Cu stabilizes the orthorhombic structure (Fmmm) of the perovskite, while A-site doping with Ba yields a tetragonal space group (I4/mmm). We observed the orthorhombic-to-tetragonal transformation above 170 °C for La2Ni0.9Cu0.1O4 and La2Ni0.8Cu0.2O4, slightly higher than for undoped La2NiO4. Loss of oxygen in interstitial sites of the tetragonal structure causes further structure transformations for all samples before decomposition in the temperature range of 400 °C-600 °C. Controlled in situ decomposition of the parent or A/B-site doped perovskite structures in a DRM mixture (CH4:CO2 = 1:1) in all cases yields an active phase consisting of exsolved nanocrystalline metallic Ni particles in contact with hexagonal La2O3 and a mixture of (oxy)carbonate phases (hexagonal and monoclinic La2O2CO3, BaCO3). Differences in the catalytic activity evolve because of (i) the in situ formation of Ni-Cu alloy phases (in a composition of >7:1 = Ni:Cu) for La2Ni0.9Cu0.1O4, La2Ni0.8Cu0.2O4, and La1.8Ba0.2Ni0.9Cu0.1O4, (ii) the resulting Ni particle size and amount of exsolved Ni, and (iii) the inherently different reactivity of the present (oxy)carbonate species. Based on the onset temperature of catalytic DRM activity, the latter decreases in the order of La2Ni0.9Cu0.1O4 ∼ La2Ni0.8Cu0.2O4 ≥ La1.8Ba0.2Ni0.9Cu0.1O4 > La2NiO4 > La1.8Ba0.2NiO4. Simple A-site doped La1.8Ba0.2NiO4 is essentially DRM inactive. The Ni particle size can be efficiently influenced by introducing Ba into the A site of the respective Ruddlesden-Popper structures, allowing us to control the Ni particle size between 10 nm and 30 nm both for simple B-site and A-site doped structures. Hence, it is possible to steer both the extent of the metal-oxide-(oxy)carbonate interface and its chemical composition and reactivity. Counteracting the limitation of the larger Ni particle size, the activity can, however, be improved by additional Cu-doping on the B-site, enhancing the carbon reactivity. Exemplified for the La2NiO4 based systems, we show how the delicate antagonistic balance of doping with Cu (rendering the La2NiO4 structure less stable and suppressing coking by efficiently removing surface carbon) and Ba (rendering the La2NiO4 structure more stable and forming unreactive surface or interfacial carbonates) can be used to tailor prospective DRM-active catalysts.
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Affiliation(s)
- Maged F. Bekheet
- Fachgebiet Keramische
Werkstoffe/Chair of Advanced Ceramic Materials, Institut für
Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Parastoo Delir Kheyrollahi Nezhad
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, University of Tabriz, Tabriz 51386, Iran
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Nicolas Bonmassar
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Lukas Schlicker
- Fachgebiet Keramische
Werkstoffe/Chair of Advanced Ceramic Materials, Institut für
Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Albert Gili
- Fachgebiet Keramische
Werkstoffe/Chair of Advanced Ceramic Materials, Institut für
Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Sebastian Praetz
- Institute of Optics
and Atomic Physics, Technische Universität
Berlin, Hardenbergstraße
36, 10623 Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische
Werkstoffe/Chair of Advanced Ceramic Materials, Institut für
Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley, California 94720, United States
| | - Yuanxu Gao
- Ernst Ruska-Centrum
für Mikroskopie und Spektroskopie mit Elektronen Forschungszentrum
Jülich GmbH 52425 Jülich, Germany
| | - Marc Heggen
- Ernst Ruska-Centrum
für Mikroskopie und Spektroskopie mit Elektronen Forschungszentrum
Jülich GmbH 52425 Jülich, Germany
| | - Aligholi Niaei
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, University of Tabriz, Tabriz 51386, Iran
| | - Ali Farzi
- Reactor & Catalyst Research Lab, Department of Chemical Engineering, University of Tabriz, Tabriz 51386, Iran
| | - Sabine Schwarz
- University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Johannes Bernardi
- University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Bernhard Klötzer
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
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11
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Ploner K, Watschinger M, Kheyrollahi Nezhad PD, Götsch T, Schlicker L, Köck EM, Gurlo A, Gili A, Doran A, Zhang L, Köwitsch N, Armbrüster M, Vanicek S, Wallisch W, Thurner C, Klötzer B, Penner S. Mechanistic insights into the catalytic methanol steam reforming performance of Cu/ZrO2 catalysts by in situ and operando studies. J Catal 2020. [DOI: 10.1016/j.jcat.2020.09.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Carbide-Modified Pd on ZrO2 as Active Phase for CO2-Reforming of Methane—A Model Phase Boundary Approach. Catalysts 2020. [DOI: 10.3390/catal10091000] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Starting from subsurface Zr0-doped “inverse” Pd and bulk-intermetallic Pd0Zr0 model catalyst precursors, we investigated the dry reforming reaction of methane (DRM) using synchrotron-based near ambient pressure in-situ X-ray photoelectron spectroscopy (NAP-XPS), in-situ X-ray diffraction and catalytic testing in an ultrahigh-vacuum-compatible recirculating batch reactor cell. Both intermetallic precursors develop a Pd0–ZrO2 phase boundary under realistic DRM conditions, whereby the oxidative segregation of ZrO2 from bulk intermetallic PdxZry leads to a highly active composite layer of carbide-modified Pd0 metal nanoparticles in contact with tetragonal ZrO2. This active state exhibits reaction rates exceeding those of a conventional supported Pd–ZrO2 reference catalyst and its high activity is unambiguously linked to the fast conversion of the highly reactive carbidic/dissolved C-species inside Pd0 toward CO at the Pd/ZrO2 phase boundary, which serves the role of providing efficient CO2 activation sites. In contrast, the near-surface intermetallic precursor decomposes toward ZrO2 islands at the surface of a quasi-infinite Pd0 metal bulk. Strongly delayed Pd carbide accumulation and thus carbon resegregation under reaction conditions leads to a much less active interfacial ZrO2–Pd0 state.
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13
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Bonmassar N, Bekheet MF, Schlicker L, Gili A, Gurlo A, Doran A, Gao Y, Heggen M, Bernardi J, Klötzer B, Penner S. In Situ-Determined Catalytically Active State of LaNiO3 in Methane Dry Reforming. ACS Catal 2019. [DOI: 10.1021/acscatal.9b03687] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicolas Bonmassar
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Maged F. Bekheet
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley, California 94720, United States
| | - Yuanxu Gao
- Ernst Ruska-Centrum für Mikroskopie und Spektroskopie mit Elektronen, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Marc Heggen
- Ernst Ruska-Centrum für Mikroskopie und Spektroskopie mit Elektronen, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Johannes Bernardi
- University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Bernhard Klötzer
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
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14
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Shakibi Nia N, Hauser D, Schlicker L, Gili A, Doran A, Gurlo A, Penner S, Kunze-Liebhäuser J. Zirconium Oxycarbide: A Highly Stable Catalyst Material for Electrochemical Energy Conversion. Chemphyschem 2019; 20:3067-3073. [PMID: 31247128 PMCID: PMC6900196 DOI: 10.1002/cphc.201900539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/26/2019] [Indexed: 11/26/2022]
Abstract
Metal carbides and oxycarbides have recently gained considerable interest due to their (electro)catalytic properties that differ from those of transition metals and that have potential to outperform them as well. The stability of zirconium oxycarbide nanopowders (ZrO0.31C0.69), synthesized via a hybrid solid‐liquid route, is investigated in different gas atmospheres from room temperature to 800 °C by using in‐situ X‐ray diffraction and in‐situ electrical impedance spectroscopy. To feature the properties of a structurally stable Zr oxycarbide with high oxygen content, a stoichiometry of ZrO0.31C0.69 has been selected. ZrO0.31C0.69 is stable in reducing gases with only minor amounts of tetragonal ZrO2 being formed at high temperatures, whereas it decomposes in CO2 and O2 gas atmosphere. From online differential electrochemical mass spectrometry measurements, the hydrogen evolution reaction (HER) onset potential is determined at −0.4 VRHE. CO2 formation is detected at potentials as positive as 1.9 VRHE as ZrO0.31C0.69 decomposition product, and oxygen is anodically formed at 2.5 VRHE, which shows the high electrochemical stability of this material in acidic electrolyte. This peopwery makes the material suited for electrocatalytic reactions at anodic potentials, such as CO and alcohol oxidation reactions, in general.
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Affiliation(s)
- Niusha Shakibi Nia
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Daniel Hauser
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence National Laboratory Berkeley, California, 94720, USA
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Simon Penner
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Julia Kunze-Liebhäuser
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
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15
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Gili A, Schlicker L, Bekheet MF, Görke O, Kober D, Simon U, Littlewood P, Schomäcker R, Doran A, Gaissmaier D, Jacob T, Selve S, Gurlo A. Revealing the Mechanism of Multiwalled Carbon Nanotube Growth on Supported Nickel Nanoparticles by in Situ Synchrotron X-ray Diffraction, Density Functional Theory, and Molecular Dynamics Simulations. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00733] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Maged F. Bekheet
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Oliver Görke
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Delf Kober
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Ulla Simon
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Patrick Littlewood
- Center for Catalysis and Surface Science, Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Reinhard Schomäcker
- Institut für Chemie, Technische Universität Berlin, Sekretariat TC 8, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel Gaissmaier
- Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
- Helmholtz-Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstraße 11, 89081 Ulm, Germany
- Karlsruhe Institute of Technology (KIT), P.O. Box
3640, 76021 Karlsruhe, Germany
| | - Timo Jacob
- Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
- Helmholtz-Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstraße 11, 89081 Ulm, Germany
- Karlsruhe Institute of Technology (KIT), P.O. Box
3640, 76021 Karlsruhe, Germany
| | - Sören Selve
- Center for Electron Microscopy (ZELMI), Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
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16
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Ploner K, Schlicker L, Gili A, Gurlo A, Doran A, Zhang L, Armbrüster M, Obendorf D, Bernardi J, Klötzer B, Penner S. Reactive metal-support interaction in the Cu-In 2O 3 system: intermetallic compound formation and its consequences for CO 2-selective methanol steam reforming. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2019; 20:356-366. [PMID: 31068984 PMCID: PMC6493314 DOI: 10.1080/14686996.2019.1590127] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 06/09/2023]
Abstract
The reactive metal-support interaction in the Cu-In2O3 system and its implications on the CO2 selectivity in methanol steam reforming (MSR) have been assessed using nanosized Cu particles on a powdered cubic In2O3 support. Reduction in hydrogen at 300 °C resulted in the formation of metallic Cu particles on In2O3. This system already represents a highly CO2-selective MSR catalyst with ~93% selectivity, but only 56% methanol conversion and a maximum H2 formation rate of 1.3 µmol gCu -1 s-1. After reduction at 400 °C, the system enters an In2O3-supported intermetallic compound state with Cu2In as the majority phase. Cu2In exhibits markedly different self-activating properties at equally pronounced CO2 selectivities between 92% and 94%. A methanol conversion improvement from roughly 64% to 84% accompanied by an increase in the maximum hydrogen formation rate from 1.8 to 3.8 µmol gCu -1 s-1 has been observed from the first to the fourth consecutive runs. The presented results directly show the prospective properties of a new class of Cu-based intermetallic materials, beneficially combining the MSR properties of the catalyst's constituents Cu and In2O3. In essence, the results also open up the pathway to in-depth development of potentially CO2-selective bulk intermetallic Cu-In compounds with well-defined stoichiometry in MSR.
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Affiliation(s)
- Kevin Ploner
- Department of Physical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Berlin, Germany
| | - Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Lei Zhang
- Faculty of Natural Sciences, Institute of Chemistry, Materials for Innovative Energy Concepts, Chemnitz University of Technology, Chemnitz, Germany
| | - Marc Armbrüster
- Faculty of Natural Sciences, Institute of Chemistry, Materials for Innovative Energy Concepts, Chemnitz University of Technology, Chemnitz, Germany
| | - Dagmar Obendorf
- Institut für Analytische Chemie und Radiochemie, University of Innsbruck, Innsbruck, Austria
| | - Johannes Bernardi
- University Service Center for Transmission Electron Microscopy, Vienna, Austria
| | - Bernhard Klötzer
- Department of Physical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Simon Penner
- Department of Physical Chemistry, University of Innsbruck, Innsbruck, Austria
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17
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Bekheet MF, Grünbacher M, Schlicker L, Gili A, Doran A, Epping JD, Gurlo A, Klötzer B, Penner S. On the structural stability of crystalline ceria phases in undoped and acceptor-doped ceria materials under in situ reduction conditions. CrystEngComm 2019; 21:145-154. [PMID: 30930690 PMCID: PMC6394889 DOI: 10.1039/c8ce01726c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/01/2018] [Indexed: 11/21/2022]
Abstract
The reduction of pure and Sm-doped ceria in hydrogen has been studied by synchrotron-based in situ X-ray diffraction to eventually prove or disprove the presence of crystalline cerium hydride (CeH x ) phases and the succession of potential structural phase (trans)formations of reduced cerium oxide phases during heating-cooling cycles up to 1273 K. Despite a recent report on the existence of bulk and surface CeH x phases during reductive treatment of pure CeO2 in H2, structural analysis by Rietveld refinement as well as additional 1H-NMR spectroscopy did not reveal the presence of any crystalline CeH x phase. Rather, a sequence of phase transformations during the re-cooling process in H2 has been observed. In both samples, the reduced/defective fluorite lattice undergoes at first a transformation into a bixbyite-type lattice with a formal stoichiometry Ce0.58 3+Ce0.42 4+O1.71 and Sm0.15 3+Ce0.39 3+Ce0.46 4+O1.73, before a transformation into rhombohedral Ce7O12 takes place in pure CeO2. This phase is clearly absent for the Sm-doped material. Finally, a triclinic Ce11O20 phase appears for both materials, which can be recovered to room temperature, and on which a phase mixture of bixbyite Ce0.66 3+Ce0.34 4+O1.67, rh-Ce0.60 3+Ce0.40 4+O1.70 and tri-Ce0.48 3+Ce0.52 4+O1.76 (for pure CeO2) or bixbyite Sm0.15 3+Ce0.47 3+Ce0.38 4+O1.69 and tri-Sm0.15 3+Ce0.31 3+Ce0.54 4+O1.77 (for Sm-doped CeO2) prevails. The absence of the rhombohedral phase indicates that Sm doping leads to the stabilization of the bixbyite phase over the rhombohedral one at this particular oxygen vacancy concentration. It is worth noting that recent work proves that hydrogen is indeed incorporated within the structures during the heat treatments, but under the chosen experimental conditions it has apparently no effect on the salient structural principles during reduction.
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Affiliation(s)
- Maged F Bekheet
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials , Institut für Werkstoffwissenschaften und -technologien , Technische Universität Berlin , Hardenbergstr. 40 , 10623 Berlin , Germany
| | - Matthias Grünbacher
- Institute of Physical Chemistry , University of Innsbruck , Innrain 52c , A-6020 Innsbruck , Austria . ; Tel: +43 512 507 58003
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials , Institut für Werkstoffwissenschaften und -technologien , Technische Universität Berlin , Hardenbergstr. 40 , 10623 Berlin , Germany
| | - Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials , Institut für Werkstoffwissenschaften und -technologien , Technische Universität Berlin , Hardenbergstr. 40 , 10623 Berlin , Germany
| | - Andrew Doran
- Advanced Light Source , Lawrence Berkeley National Laboratory Berkeley , California 94720 , USA
| | - Jan Dirk Epping
- Fakultät II : Mathematik & Naturwissenschaften , Institut für Chemie , Technische Universität Berlin , Hardenbergstr. 40 , 10623 Berlin , Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials , Institut für Werkstoffwissenschaften und -technologien , Technische Universität Berlin , Hardenbergstr. 40 , 10623 Berlin , Germany
| | - Bernhard Klötzer
- Institute of Physical Chemistry , University of Innsbruck , Innrain 52c , A-6020 Innsbruck , Austria . ; Tel: +43 512 507 58003
| | - Simon Penner
- Institute of Physical Chemistry , University of Innsbruck , Innrain 52c , A-6020 Innsbruck , Austria . ; Tel: +43 512 507 58003
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Götsch T, Köpfle N, Grünbacher M, Bernardi J, Carbonio EA, Hävecker M, Knop-Gericke A, Bekheet MF, Schlicker L, Doran A, Gurlo A, Franz A, Klötzer B, Penner S. Crystallographic and electronic evolution of lanthanum strontium ferrite (La0.6Sr0.4FeO3−δ) thin film and bulk model systems during iron exsolution. Phys Chem Chem Phys 2019; 21:3781-3794. [DOI: 10.1039/c8cp07743f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We study the changes in the crystallographic phases and in the chemical states during the iron exsolution process of lanthanum strontium ferrite (LSF, La0.6Sr0.4FeO3−δ).
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Schlicker L, Bekheet MF, Gili A, Doran A, Gurlo A, Ploner K, Schachinger T, Penner S. Hydrogen reduction and metal-support interaction in a metastable metal-oxide system: Pd on rhombohedral In2O3. J SOLID STATE CHEM 2018. [DOI: 10.1016/j.jssc.2018.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Götsch T, Ploner K, Bernardi J, Schlicker L, Gili A, Doran A, Gurlo A, Penner S. Formation of Pd-Ce intermetallic compounds by reductive metal-support interaction. J SOLID STATE CHEM 2018. [DOI: 10.1016/j.jssc.2018.05.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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21
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Gili A, Schlicker L, Bekheet MF, Görke O, Penner S, Grünbacher M, Götsch T, Littlewood P, Marks TJ, Stair PC, Schomäcker R, Doran A, Selve S, Simon U, Gurlo A. Surface Carbon as a Reactive Intermediate in Dry Reforming of Methane to Syngas on a 5% Ni/MnO Catalyst. ACS Catal 2018. [DOI: 10.1021/acscatal.8b01820] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Maged F. Bekheet
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Oliver Görke
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Simon Penner
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Matthias Grünbacher
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Thomas Götsch
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Patrick Littlewood
- Center for Catalysis and Surface Science, Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Tobin J. Marks
- Center for Catalysis and Surface Science, Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Peter C. Stair
- Center for Catalysis and Surface Science, Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Reinhard Schomäcker
- Institut für Chemie, Technische Universität Berlin, Sekretariat TC 8, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sören Selve
- Center for Electron Microscopy (ZELMI), Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Ulla Simon
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und-technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin, Germany
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