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Rudolph B, Tsiotsias AI, Ehrhardt B, Dolcet P, Gross S, Haas S, Charisou ND, Goula MA, Mascotto S. Nanoparticle Exsolution from Nanoporous Perovskites for Highly Active and Stable Catalysts. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205890. [PMID: 36683242 PMCID: PMC9951582 DOI: 10.1002/advs.202205890] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Nanoporosity is clearly beneficial for the performance of heterogeneous catalysts. Although exsolution is a modern method to design innovative catalysts, thus far it is predominantly studied for sintered matrices. A quantitative description of the exsolution of Ni nanoparticles from nanoporous perovskite oxides and their effective application in the biogas dry reforming is here presented. The exsolution process is studied between 500 and 900 °C in nanoporous and sintered La0.52 Sr0.28 Ti0.94 Ni0.06 O3±δ . Using temperature-programmed reduction (TPR) and X-ray absorption spectroscopy (XAS), it is shown that the faster and larger oxygen release in the nanoporous material is responsible for twice as high Ni reduction than in the sintered system. For the nanoporous material, the nanoparticle formation mechanism, studied by in situ TEM and small-angle X-ray scattering (SAXS), follows the classical nucleation theory, while on sintered systems also small endogenous nanoparticles form despite the low Ni concentration. Biogas dry reforming tests demonstrate that nanoporous exsolved catalysts are up to 18 times more active than sintered ones with 90% of CO2 conversion at 800 °C. Time-on-stream tests exhibit superior long-term stability (only 3% activity loss in 8 h) and full regenerability (over three cycles) of the nanoporous exsolved materials in comparison to a commercial Ni/Al2 O3 catalyst.
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Affiliation(s)
- Benjamin Rudolph
- Institut für Anorganische und Angewandte ChemieUniversität HamburgMartin‐Luther‐King‐Platz, 620146HamburgGermany
| | | | - Benedikt Ehrhardt
- Institut für Anorganische und Angewandte ChemieUniversität HamburgMartin‐Luther‐King‐Platz, 620146HamburgGermany
| | - Paolo Dolcet
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of TechnologyEngesserstrasse 2076133KarlsruheGermany
| | - Silvia Gross
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of TechnologyEngesserstrasse 2076133KarlsruheGermany
- Dipartimento di Scienze ChimicheUniversità degli Studi di Padovavia Marzolo 1Padova35131Italy
| | - Sylvio Haas
- Deutsches Elektronen Synchrotron (DESY)Notkestr. 8522607HamburgGermany
| | - Nikolaos D. Charisou
- Department of Chemical EngineeringUniversity of Western MacedoniaKoilaKozani50100Greece
| | - Maria A. Goula
- Department of Chemical EngineeringUniversity of Western MacedoniaKoilaKozani50100Greece
| | - Simone Mascotto
- Institut für Anorganische und Angewandte ChemieUniversität HamburgMartin‐Luther‐King‐Platz, 620146HamburgGermany
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Poffe E, Kaper H, Ehrhardt B, Gigli L, Aubert D, Nodari L, Gross S, Mascotto S. Understanding Oxygen Release from Nanoporous Perovskite Oxides and Its Effect on the Catalytic Oxidation of CH 4 and CO. ACS APPLIED MATERIALS & INTERFACES 2021; 13:25483-25492. [PMID: 34006105 DOI: 10.1021/acsami.1c02281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The design of nanoporous perovskite oxides is considered an efficient strategy to develop performing, sustainable catalysts for the conversion of methane. The dependency of nanoporosity on the oxygen defect chemistry and the catalytic activity of perovskite oxides toward CH4 and CO oxidation was studied here. A novel colloidal synthesis route for nanoporous, high-temperature stable SrTi0.65Fe0.35O3-δ with specific surface areas (SSA) ranging from 45 to 80 m2/g and pore sizes from 10 to 100 nm was developed. High-temperature investigations by in situ synchrotron X-ray diffraction (XRD) and TG-MS combined with H2-TPR and Mössbauer spectroscopy showed that the porosity improved the release of surface oxygen and the oxygen diffusion, whereas the release of lattice oxygen depended more on the state of the iron species and strain effects in the materials. Regarding catalysis, light-off tests showed that low-temperature CO oxidation significantly benefitted from the enhancement of the SSA, whereas high-temperature CH4 oxidation is influenced more by the dioxygen release. During isothermal long-term catalysis tests, however, the continuous oxygen release from large SSA materials promoted both CO and CH4 conversion. Hence, if SSA maximization turned out to efficiently improve low-temperature and long-term catalysis applications, the role of both reducible metal center concentration and crystal structure cannot be completely ignored, as they also contribute to the perovskite oxygen release properties.
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Affiliation(s)
- Elisa Poffe
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
| | - Helena Kaper
- Ceramic Synthesis and Functionalization Laboratory, CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, 550, Ave Alphonse Jauffret, 84306 Cavaillon, France
| | - Benedikt Ehrhardt
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
| | - Lara Gigli
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, 34149 Basovizza, Trieste, Italy
| | - Daniel Aubert
- Ceramic Synthesis and Functionalization Laboratory, CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, 550, Ave Alphonse Jauffret, 84306 Cavaillon, France
| | - Luca Nodari
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
- Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia, ICMATE-CNR, C.so Stati Uniti 4, 35127 Padova, Italy
| | - Silvia Gross
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
- Centro Levi Cases, Università degli Studi di Padova, via Marzolo 9, 35131 Padova, Italy
| | - Simone Mascotto
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
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