1
|
Montes-Monroy JM, Manzorro R, Chinchilla LE, Celín WE, Calvino JJ, Pérez-Omil JA. Supported Ce/Zr pyrochlore monolayers as a route to single cerium atom catalysts with low temperature reducibility. iScience 2023; 26:107506. [PMID: 37636072 PMCID: PMC10448079 DOI: 10.1016/j.isci.2023.107506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/09/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023] Open
Abstract
The combination of structural characterization at atomic resolution, chemical data, and theoretical insights has revealed the unique nanostructures which develop in ceria supported on yttria-stabilized zirconia (YSZ) after being submitted to high-temperature reducing treatments. The results show that just a small ceria loading is needed for creating a supported Zr-rich pyrochlore (111) nanostructure, resembling the structure of single cerium atom catalysts. The specific atomic arrangement of this nanostructure allows to explain the improvement of the reducibility at low temperature. The reduction mechanism can be extrapolated to ceria-zirconia mixed oxides with pyrochlore-like cationic ordering, exposing Zr-rich (111) surfaces. The results gathered here provide key information to understand the redox behavior of these types of systems, which may contribute to improving the design of new ceria-zirconia based materials, with lower content of the lanthanide element, nearly 100% cerium atom utilization, and applications in environmental catalysis.
Collapse
Affiliation(s)
- Jose M. Montes-Monroy
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| | - Ramón Manzorro
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| | - Lidia E. Chinchilla
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| | - William E. Celín
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| | - Jose J. Calvino
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| | - Jose A. Pérez-Omil
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
- Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain
| |
Collapse
|
2
|
Insights from a Bibliometrics-Based Analysis of Publishing and Research Trends on Cerium Oxide from 1990 to 2020. Int J Mol Sci 2023; 24:ijms24032048. [PMID: 36768372 PMCID: PMC9916443 DOI: 10.3390/ijms24032048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 12/29/2022] [Accepted: 12/29/2022] [Indexed: 01/21/2023] Open
Abstract
The purpose of this study is to evaluate the literature for research trends on cerium oxide from 1990 to 2020 and identify gaps in knowledge in the emerging application(s) of CeONP. Bibliometric methods were used to identify themes in database searches from PubMed, Scopus and Web of Science Core Collection using SWIFT-Review, VOSviewer and SciMAT software programs. A systematic review was completed on published cerium oxide literature extracted from the Scopus database (n = 17,115), identifying themes relevant to its industrial, environmental and biomedical applications. A total of 172 publications were included in the systematic analysis and categorized into four time periods with research themes identified; "doping additives" (n = 5, 1990-1997), "catalysts" (n = 32, 1998-2005), "reactive oxygen species" (n = 66, 2006-2013) and "pathology" (n = 69, 2014-2020). China and the USA showed the highest number of citations and publications for cerium oxide research from 1990 to 2020. Longitudinal analysis showed CeONP has been extensively used for various applications due to its catalytic properties. In conclusion, this study showed the trend in research in CeONP over the past three decades with advancements in nanoparticle engineering like doping, and more recently surface modification or functionalization to further enhanced its antioxidant abilities. As a result of recent nanoparticle engineering developments, research into CeONP biological effects have highlighted its therapeutic potential for a range of human pathologies such as Alzheimer's disease. Whilst research over the past three decades show the versatility of cerium oxide in industrial and environmental applications, there are still research opportunities to investigate the potential beneficial effects of CeONP in its application(s) on human health.
Collapse
|
3
|
Kulal N, Bhat SS, Hugar V, Mallannavar CN, Lee SC, Bhattacharjee S, Vetrivel R, Shanbhag GV. Integrated DFT and experimental study on Co3O4/CeO2 catalyst for direct synthesis of dimethyl carbonate from CO2. J CO2 UTIL 2023. [DOI: 10.1016/j.jcou.2022.102323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
4
|
Polychronopoulou K, AlKhoori S, AlBedwawi S, Alareeqi S, Hussien AGS, Vasiliades MA, Efstathiou AM, Petallidou KC, Singh N, Anjum DH, Vega LF, Baker MA. Decoupling the Chemical and Mechanical Strain Effect on Steering the CO 2 Activation over CeO 2-Based Oxides: An Experimental and DFT Approach. ACS APPLIED MATERIALS & INTERFACES 2022; 14:33094-33119. [PMID: 35820019 PMCID: PMC9335529 DOI: 10.1021/acsami.2c05714] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Doped ceria-based metal oxides are widely used as supports and stand-alone catalysts in reactions where CO2 is involved. Thus, it is important to understand how to tailor their CO2 adsorption behavior. In this work, steering the CO2 activation behavior of Ce-La-Cu-O ternary oxide surfaces through the combined effect of chemical and mechanical strain was thoroughly examined using both experimental and ab initio modeling approaches. Doping with aliovalent metal cations (La3+ or La3+/Cu2+) and post-synthetic ball milling were considered as the origin of the chemical and mechanical strain of CeO2, respectively. Experimentally, microwave-assisted reflux-prepared Ce-La-Cu-O ternary oxides were imposed into mechanical forces to tune the structure, redox ability, defects, and CO2 surface adsorption properties; the latter were used as key descriptors. The purpose was to decouple the combined effect of the chemical strain (εC) and mechanical strain (εM) on the modification of the Ce-La-Cu-O surface reactivity toward CO2 activation. During the ab initio calculations, the stability (energy of formation, EOvf) of different configurations of oxygen vacant sites (Ov) was assessed under biaxial tensile strain (ε > 0) and compressive strain (ε < 0), whereas the CO2-philicity of the surface was assessed at different levels of the imposed mechanical strain. The EOvf values were found to decrease with increasing tensile strain. The Ce-La-Cu-O(111) surface exhibited the lowest EOvf values for the single subsurface sites, implying that Ov may occur spontaneously upon Cu addition. The mobility of the surface and bulk oxygen anions in the lattice contributing to the Ov population was measured using 16O/18O transient isothermal isotopic exchange experiments; the maximum in the dynamic rate of 16O18O formation, Rmax(16O18O), was 13.1 and 8.5 μmol g-1 s-1 for pristine (chemically strained) and dry ball-milled (chemically and mechanically strained) oxides, respectively. The CO2 activation pathway (redox vs associative) was experimentally probed using in situ diffuse reflectance infrared Fourier transform spectroscopy. It was demonstrated that the mechanical strain increased up to 6 times the CO2 adsorption sites, though reducing their thermal stability. This result supports the mechanical actuation of the "carbonate"-bound species; the latter was in agreement with the density functional theory (DFT)-calculated C-O bond lengths and O-C-O angles. Ab initio studies shed light on the CO2 adsorption energy (Eads), suggesting a covalent bonding which is enhanced in the presence of doping and under tensile strain. Bader charge analysis probed the adsorbate/surface charge distribution and illustrated that CO2 interacts with the dual sites (acidic and basic ones) on the surface, leading to the formation of bidentate carbonate species. Density of states (DOS) studies revealed a significant Eg drop in the presence of double Ov and compressive strain, a finding with design implications in covalent type of interactions. To bridge this study with industrially important catalytic applications, Ni-supported catalysts were prepared using pristine and ball-milled oxides and evaluated for the dry reforming of methane reaction. Ball milling was found to induce modification of the metal-support interface and Ni catalyst reducibility, thus leading to an increase in the CH4 and CO2 conversions. This study opens new possibilities to manipulate the CO2 activation for a portfolio of heterogeneous reactions.
Collapse
Affiliation(s)
- Kyriaki Polychronopoulou
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Sara AlKhoori
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Shaima AlBedwawi
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Seba Alareeqi
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department
of Chemical Engineering and Research and Innovation Center on CO2
and Hydrogen (RICH Center), Khalifa University
of Science and Technology, Abu
Dhabi 127788, United Arab
Emirates
| | - Aseel G. S. Hussien
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Michalis A. Vasiliades
- Department
of Chemistry, Heterogeneous Catalysis Laboratory, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Angelos M. Efstathiou
- Department
of Chemistry, Heterogeneous Catalysis Laboratory, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Klito C. Petallidou
- Department
of Chemistry, Heterogeneous Catalysis Laboratory, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Nirpendra Singh
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department
of Physics, Khalifa University of Science
and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Dalaver H. Anjum
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department
of Physics, Khalifa University of Science
and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Lourdes F. Vega
- Center
for Catalysis and Separations (CeCaS Center), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department
of Chemical Engineering and Research and Innovation Center on CO2
and Hydrogen (RICH Center), Khalifa University
of Science and Technology, Abu
Dhabi 127788, United Arab
Emirates
| | - Mark A. Baker
- The
Surface
Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 4DL, U.K.
| |
Collapse
|
5
|
Hinuma Y, Mine S, Toyao T, Shimizu KI. Trends in Surface Oxygen Formation Energy in Perovskite Oxides. ACS OMEGA 2022; 7:18427-18433. [PMID: 35694487 PMCID: PMC9178614 DOI: 10.1021/acsomega.2c00702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Perovskite oxides comprise an important class of materials, and some of their applications depend on the surface reactivity characteristics. We calculated, using density functional theory, the surface O vacancy formation energy (E Ovac) for perovskite-structure oxides, with a transition metal (Ti-Fe) as the B-site cation, to estimate the catalytic reactivity of perovskite oxides. The E Ovac value correlated well with the band gap and bulk formation energy, which is a trend also found in other oxides. A low E Ovac value, which is expected to result in higher catalytic activity via the Mars-van Krevelen mechanism, was found in metallic perovskites such as CaCoO3, BaFeO3, and SrFeO3. On the other hand, titanates had high E Ovac values, typically exceeding 4 eV/atom, suggesting that these materials are less reactive when O vacancy formation is involved in the reaction mechanism.
Collapse
Affiliation(s)
- Yoyo Hinuma
- Department
of Energy and Environment, National Institute
of Advanced Industrial Science and Technology (AIST), 1-8-31, Midorigaoka, Ikeda 563-8577, Japan
| | - Shinya Mine
- Institute
for Catalysis, Hokkaido University, N-21, W-10, 1-5, Sapporo 001-0021, Japan
| | - Takashi Toyao
- Institute
for Catalysis, Hokkaido University, N-21, W-10, 1-5, Sapporo 001-0021, Japan
- Elements
Strategy Initiative for Catalysts and Batteries, Kyoto University, Katsura, Kyoto 615-8520, Japan
| | - Ken-ichi Shimizu
- Institute
for Catalysis, Hokkaido University, N-21, W-10, 1-5, Sapporo 001-0021, Japan
- Elements
Strategy Initiative for Catalysts and Batteries, Kyoto University, Katsura, Kyoto 615-8520, Japan
| |
Collapse
|
6
|
Using XRD extrapolation method to design Ce-Cu-O solid solution catalysts for methanol steam reforming to produce H2: The effect of CuO lattice capacity on the reaction performance. Catal Today 2022. [DOI: 10.1016/j.cattod.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
7
|
Miran HA, Jaf ZN, Altarawneh M, Jiang ZT. An Insight into Geometries and Catalytic Applications of CeO 2 from a DFT Outlook. Molecules 2021; 26:6485. [PMID: 34770889 PMCID: PMC8588098 DOI: 10.3390/molecules26216485] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 11/18/2022] Open
Abstract
Rare earth metal oxides (REMOs) have gained considerable attention in recent years owing to their distinctive properties and potential applications in electronic devices and catalysts. Particularly, cerium dioxide (CeO2), also known as ceria, has emerged as an interesting material in a wide variety of industrial, technological, and medical applications. Ceria can be synthesized with various morphologies, including rods, cubes, wires, tubes, and spheres. This comprehensive review offers valuable perceptions into the crystal structure, fundamental properties, and reaction mechanisms that govern the well-established surface-assisted reactions over ceria. The activity, selectivity, and stability of ceria, either as a stand-alone catalyst or as supports for other metals, are frequently ascribed to its strong interactions with the adsorbates and its facile redox cycle. Doping of ceria with transition metals is a common strategy to modify the characteristics and to fine-tune its reactive properties. DFT-derived chemical mechanisms are surveyed and presented in light of pertinent experimental findings. Finally, the effect of surface termination on catalysis by ceria is also highlighted.
Collapse
Affiliation(s)
- Hussein A. Miran
- Department of Physics, College of Education for Pure Science, Ibn Al-Haitham, University of Baghdad, Baghdad 10071, Iraq;
| | - Zainab N. Jaf
- Department of Physics, College of Education for Pure Science, Ibn Al-Haitham, University of Baghdad, Baghdad 10071, Iraq;
| | - Mohammednoor Altarawneh
- Department of Chemical and Petroleum Engineering, United Arab Emirates University, Sheikh Khalifa Bin Zayed Street, Al-Ain 15551, United Arab Emirates
| | - Zhong-Tao Jiang
- Surface Analysis and Materials Engineering Research Group, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA 6150, Australia;
| |
Collapse
|
8
|
Pérez-Bailac P, Lustemberg PG, Ganduglia-Pirovano MV. Facet-dependent stability of near-surface oxygen vacancies and excess charge localization at CeO 2surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:504003. [PMID: 34479232 DOI: 10.1088/1361-648x/ac238b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/03/2021] [Indexed: 05/25/2023]
Abstract
To study the dependence of the relative stability of surface (VA) and subsurface (VB) oxygen vacancies with the crystal facet of CeO2, the reduced (100), (110) and (111) surfaces, with two different concentrations of vacancies, were investigated by means of density functional theory (DFT + U) calculations. The results show that the trend in the near-surface vacancy formation energies for comparable vacancy spacings, i.e. (110) < (100) < (111), does not follow the one in the surface stability of the facets, i.e. (111) < (110) < (100). The results also reveal that the preference of vacancies for surface or subsurface sites, as well as the preferred location of the associated Ce3+polarons, are facet- and concentration-dependent. At the higher vacancy concentration, theVAis more stable than theVBat the (110) facet whereas at the (111), it is the other way around, and at the (100) facet, both theVAand theVBhave similar stability. The stability of theVAvacancies, compared to that of theVB, is accentuated as the concentration decreases. Nearest neighbor polarons to the vacant sites are only observed for the less densely packed (110) and (100) facets. These findings are rationalized in terms of the packing density of the facets, the lattice relaxation effects induced by vacancy formation and the localization of the excess charge, as well as the repulsive Ce3+-Ce3+interactions.
Collapse
Affiliation(s)
- Patricia Pérez-Bailac
- Instituto de Catálisis y Petroleoquímica (ICP-CSIC), C/Marie Curie 2, 28049 Madrid, Spain
- PhD Programme in Applied Chemistry, Doctoral School, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 2, 28049 Ciudad Universitaria de Cantoblanco, Madrid, Spain
| | - Pablo G Lustemberg
- Instituto de Catálisis y Petroleoquímica (ICP-CSIC), C/Marie Curie 2, 28049 Madrid, Spain
- Instituto de Física Rosario (IFIR-CONICET), Ocampo y Esmeralda, S2000EKF Rosario, Santa Fe, Argentina
| | | |
Collapse
|
9
|
Huizenga C, Hratchian HP, Jarrold CC. Lanthanide Oxides: From Diatomics to High-Spin, Strongly Correlated Homo- and Heterometallic Clusters. J Phys Chem A 2021; 125:6315-6331. [PMID: 34265204 DOI: 10.1021/acs.jpca.1c04253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Small lanthanide (Ln) oxide clusters present both experimental and theoretical challenges because of their partially filled, core-like 4f n orbitals, a feature that results in a plethora of close-lying and fundamentally similar electronic states. These clusters provide a bottom-up approach toward understanding the electronic structure of defective or doped bulk material but also can offer a challenge to the theorists to find a method robust enough to capture electronic structure patterns that emerge from within the 4f n (0 < n < 14) series. In this Feature Article, we explore the electronic structures of small lanthanide oxide clusters that deviate from bulk stoichiometry using anion photoelectron spectroscopy and supporting density functional theory calculations. We will describe the evolution of electronic structure with oxidation and how LnxOy- cluster reactivities can be correlated with specific Ln-local orbital occupancies. These strongly correlated systems offer additional insights into how interactions between electrons and electronically complex neutrals can lead to detachment transitions that lie outside of the sudden one-electron detachment approximation generally assumed in anion photoelectron spectroscopy. With a better understanding of how we can control nominally forbidden transitions to sample an array of spin states, we suggest that more in-depth studies on the magnetic states of these systems can be explored. Extending these studies to other Ln-based materials with hidden magnetic phases, along with sequentially ligated single molecule magnets, could advance current understanding of these systems.
Collapse
Affiliation(s)
- Caleb Huizenga
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hrant P Hratchian
- Department of Chemistry and Chemical Biology, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| |
Collapse
|
10
|
Polychronopoulou K, AlKhoori AA, Efstathiou AM, Jaoude MA, Damaskinos CM, Baker MA, Almutawa A, Anjum DH, Vasiliades MA, Belabbes A, Vega LF, Zedan AF, Hinder SJ. Design Aspects of Doped CeO 2 for Low-Temperature Catalytic CO Oxidation: Transient Kinetics and DFT Approach. ACS APPLIED MATERIALS & INTERFACES 2021; 13:22391-22415. [PMID: 33834768 PMCID: PMC8153538 DOI: 10.1021/acsami.1c02934] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
CO elimination through oxidation over highly active and cost-effective catalysts is a way forward for many processes of industrial and environmental importance. In this study, doped CeO2 with transition metals (TM = Cu, Co, Mn, Fe, Ni, Zr, and Zn) at a level of 20 at. % was tested for CO oxidation. The oxides were prepared using microwave-assisted sol-gel synthesis to improve catalyst's performance for the reaction of interest. The effect of heteroatoms on the physicochemical properties (structure, morphology, porosity, and reducibility) of the binary oxides M-Ce-O was meticulously investigated and correlated to their CO oxidation activity. It was found that the catalytic activity (per gram basis or TOF, s-1) follows the order Cu-Ce-O > Ce-Co-O > Ni-Ce-O > Mn-Ce-O > Fe-Ce-O > Ce-Zn-O > CeO2. Participation of mobile lattice oxygen species in the CO/O2 reaction does occur, the extent of which is heteroatom-dependent. For that, state-of-the-art transient isotopic 18O-labeled experiments involving 16O/18O exchange followed by step-gas CO/Ar or CO/O2/Ar switches were used to quantify the contribution of lattice oxygen to the reaction. SSITKA-DRIFTS studies probed the formation of carbonates while validating the Mars-van Krevelen (MvK) mechanism. Scanning transmission electron microscopy-high-angle annular dark field imaging coupled with energy-dispersive spectroscopy proved that the elemental composition of dopants in the individual nanoparticle of ceria is less than their composition at a larger scale, allowing the assessment of the doping efficacy. Despite the similar structural features of the catalysts, a clear difference in the Olattice mobility was also found as well as its participation (as expressed with the α descriptor) in the reaction, following the order αCu > αCo> αMn > αZn. Kinetic studies showed that it is rather the pre-exponential (entropic) factor and not the lowering of activation energy that justifies the order of activity of the solids. DFT calculations showed that the adsorption of CO on the Cu-doped CeO2 surface is more favorable (-16.63 eV), followed by Co, Mn, Zn (-14.46, -4.90, and -4.24 eV, respectively), and pure CeO2 (-0.63 eV). Also, copper compensates almost three times more charge (0.37e-) compared to Co and Mn, ca. 0.13e- and 0.10e-, respectively, corroborating for its tendency to be reduced. Surface analysis (X-ray photoelectron spectroscopy), apart from the oxidation state of the elements, revealed a heteroatom-ceria surface interaction (Oa species) of different extents and of different populations of Oa species.
Collapse
Affiliation(s)
- Kyriaki Polychronopoulou
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
| | - Ayesha A. AlKhoori
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
| | - Angelos M. Efstathiou
- Department
of Chemistry, Heterogeneous Catalysis Lab, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Maguy Abi Jaoude
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
- Department
of Chemistry, Khalifa University of Science
and Technology, Main
Campus, Abu Dhabi 127788, UAE
| | - C. M. Damaskinos
- Department
of Chemistry, Heterogeneous Catalysis Lab, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Mark A. Baker
- The
Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 4DL, U.K.
| | - Alia Almutawa
- Department
of Mechanical Engineering, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
| | - Dalaver H. Anjum
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
- Department
of Physics, Khalifa University of Science
and Technology, Main
Campus, Abu Dhabi 127788, UAE
| | - Michalis A. Vasiliades
- Department
of Chemistry, Heterogeneous Catalysis Lab, University of Cyprus, 1 University Avenue, University Campus, 2109 Nicosia, Cyprus
| | - Abderrezak Belabbes
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
| | - Lourdes F. Vega
- Center
for Catalysis and Separations, Khalifa University
of Science and Technology, Main Campus, Abu Dhabi 127788, UAE
- Research
and Innovation Center on CO2 and H2 (RICH),
and Chemical Engineering Department, Khalifa
University, Abu Dhabi 127788, UAE
| | - Abdallah Fathy Zedan
- National
Institute of Laser Enhanced Science, Cairo
University, Giza 12613, Egypt
| | - Steven J. Hinder
- The
Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 4DL, U.K.
| |
Collapse
|
11
|
Strong texture tuning along different crystalline directions in glass-supported CeO 2 thin films by ultrasonic spray pyrolysis. Sci Rep 2021; 11:2006. [PMID: 33479316 PMCID: PMC7820345 DOI: 10.1038/s41598-021-81353-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/05/2021] [Indexed: 12/04/2022] Open
Abstract
The strong facet-dependent performance of glass-supported CeO2 thin films in different applications (catalysis, smart windows, etc.) has been the target of diverse fundamental and technological approaches. However, the design of accurate, cost-effective and scalable methods with the potential for large-area coverage that produce highly textured glass-supported CeO2 thin films remains a technological challenge. In the present work, it is demonstrated that under proper tuning conditions, the ultrasonic spray pyrolysis technique enables one to obtain glass-supported polycrystalline CeO2 films with noticeable texture along both the (100) and (111) directions, as well as with randomly oriented crystallites (no texture). The influence of flow rates, solution molarity, and substrate temperature on the texture and morphological characteristics, as well as optical absorption and Raman response of the deposited films, is evaluated. The obtained results are discussed on the basis of the combined dependence of the CeO2-exposed surfaces on the thermodynamic stability of the corresponding facets and the reaction kinetics, which modulate the crystallite growth direction.
Collapse
|
12
|
Shi Q, Wang Y, Guo S, Han ZK, Ta N, Li G, Baiker A. NO reduction with CO over CuO x/CeO 2 nanocomposites: influence of oxygen vacancies and lattice strain. Catal Sci Technol 2021. [DOI: 10.1039/d1cy01161h] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The morphology-dependent population of oxygen vacancies in CuOx/CeO2 nanocomposites used for NO reduction with CO and its pivotal role in the reaction mechanism are examined in this combined experimental and first-principles study.
Collapse
Affiliation(s)
- Quanquan Shi
- College of Science, College of Materials Science and Art Design, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Yuhang Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Song Guo
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Zhong-Kang Han
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Moscow, 143026, Russia
| | - Na Ta
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Gao Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Alfons Baiker
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, Hönggerberg, HCl, CH-8093 Zurich, Switzerland
| |
Collapse
|
13
|
Ju M, Wang J, Huang J, Zhang C, Jin Y, Sun W, Li S, Chen Y. The Microstructure and Electronic Properties of Yttrium Oxide Doped With Cerium: A Theoretical Insight. Front Chem 2020; 8:338. [PMID: 32411670 PMCID: PMC7198891 DOI: 10.3389/fchem.2020.00338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/01/2020] [Indexed: 11/13/2022] Open
Abstract
Trivalent Cerium (Ce3+) doped Yttrium Oxide (Y2O3) host crystal has drawn considerable interest due to its popular optical 5d-4f transition. The outstanding optical properties of Y2O3:Ce system have been demonstrated by previous studies but the microstructures still remain unclear. The lacks of Y2O3:Ce microstructures could constitute a problem to further exploit its potential applications. In this sense, we have comprehensively investigated the structural evolutions of Y2O3:Ce crystals based on the CALYPSO structure search method in conjunction with density functional theory calculations. Our result uncovers a new rhombohedral phase of Y2O3:Ce with R-3 group symmetry. In the host crystal, the Y3+ ion at central site can be naturally replaced by the doped Ce3+, resulting in a perfect cage-like configuration. We find an interesting phase transition that the crystallographic symmetry of Y2O3 changes from cubic to rhombohedral when the impurity Ce3+ is doped into the host crystal. With the nominal concentration of Ce3+ at 3.125%, many metastable structures are also identified due to the different occupying points in the host crystal. The X-ray diffraction patterns of Y2O3:Ce are simulated and the theoretical result is comparable to experimental data, thus demonstrating the validity of the lowest energy structure. The result of phonon dispersions shows that the ground state structure is dynamically stable. The analysis of electronic properties indicate that the Y2O3:Ce possesses a band gap of 4.20 eV which suggests that the incorporation of impurity Ce3+ ion into Y2O3 host crystal leads to an insulator to semiconductor transition. Meanwhile, the strong covalent bonds of O atoms in the crystal, which may greatly contribute to the stability of ground state structure, are evidenced by electron localization function. These obtained results elucidate the structural and bonding characters of Y2O3:Ce and could also provide useful insights for understanding the experimental phenomena.
Collapse
Affiliation(s)
- Meng Ju
- School of Physical Science and Technology, Southwest University, Chongqing, China.,College of Computer and Information Engineering, Hubei Normal University, Huangshi, China
| | - Jingjing Wang
- College of Computer and Information Engineering, Hubei Normal University, Huangshi, China
| | - Jing Huang
- School of Physical Science and Technology, Southwest University, Chongqing, China
| | - Chuanzhao Zhang
- Department of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, China
| | - Yuanyuan Jin
- Department of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, China
| | - Weiguo Sun
- Centre for Science at Extreme Conditions and School of Physics and Astronomy, Scottish Universities Physics Alliance (SUPA), University of Edinburgh, Edinburgh, United Kingdom
| | - Shichang Li
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing, China
| | - Yunhong Chen
- College of Computer and Information Engineering, Hubei Normal University, Huangshi, China
| |
Collapse
|
14
|
Recent Advances on the Rational Design of Non-Precious Metal Oxide Catalysts Exemplified by CuOx/CeO2 Binary System: Implications of Size, Shape and Electronic Effects on Intrinsic Reactivity and Metal-Support Interactions. Catalysts 2020. [DOI: 10.3390/catal10020160] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Catalysis is an indispensable part of our society, massively involved in numerous energy and environmental applications. Although, noble metals (NMs)-based catalysts are routinely employed in catalysis, their limited resources and high cost hinder the widespread practical application. In this regard, the development of NMs-free metal oxides (MOs) with improved catalytic activity, selectivity and durability is currently one of the main research pillars in the area of heterogeneous catalysis. The present review, involving our recent efforts in the field, aims to provide the latest advances—mainly in the last 10 years—on the rational design of MOs, i.e., the general optimization framework followed to fine-tune non-precious metal oxide sites and their surrounding environment by means of appropriate synthetic and promotional/modification routes, exemplified by CuOx/CeO2 binary system. The fine-tuning of size, shape and electronic/chemical state (e.g., through advanced synthetic routes, special pretreatment protocols, alkali promotion, chemical/structural modification by reduced graphene oxide (rGO)) can exert a profound influence not only to the reactivity of metal sites in its own right, but also to metal-support interfacial activity, offering highly active and stable materials for real-life energy and environmental applications. The main implications of size-, shape- and electronic/chemical-adjustment on the catalytic performance of CuOx/CeO2 binary system during some of the most relevant applications in heterogeneous catalysis, such as CO oxidation, N2O decomposition, preferential oxidation of CO (CO-PROX), water gas shift reaction (WGSR), and CO2 hydrogenation to value-added products, are thoroughly discussed. It is clearly revealed that the rational design and tailoring of NMs-free metal oxides can lead to extremely active composites, with comparable or even superior reactivity than that of NMs-based catalysts. The obtained conclusions could provide rationales and design principles towards the development of cost-effective, highly active NMs-free MOs, paving also the way for the decrease of noble metals content in NMs-based catalysts.
Collapse
|