We have synthesized and tested a highly active Cu doped mesoporous CeO catalyst system for the low temperature water-gas shift (WGS) reaction. While typical oxide-supported copper WGS catalysts are characterized by high copper loadings (30-40%), the morphological properties of the mesoporous CeO material enable high catalytic activity at copper loadings as low as 1%. Operando X-ray diffraction, in situ X-ray absorption near-edge structure spectroscopy (XANES), and operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) methods were used to probe the interactions between the metal and mesoporous oxide components under reaction conditions. Copper was observed to undergo reduction from oxide to metal under WGS conditions at 150 °C, while the CeO lattice was observed to expand upon heating, indicating Ce formation correlated with CO production. The active state of the catalysts was confirmed by in situ XANES to contain Cu and partially reduced CeO. DRIFTS analysis revealed carboxyl species bound to copper during reduction, as well as formate and carbonate surface species on ceria. Lower concentrations of copper were observed to foster enhanced metal-support interactions.
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http://dx.doi.org/10.1039/c7cp02378b | DOI Listing |
J Am Chem Soc
January 2025
Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Exsolution is a promising approach for fabricating oxide-supported metal nanocatalysts through redox-driven metal precipitation. A defining feature of exsolved nanocatalysts is their anchored metal-oxide interface, which exhibits exceptional structural stability in (electro)catalysis. However, the electronic interactions at this unique interface remain unclear, despite their known impact on catalytic performance.
View Article and Find Full Text PDFRSC Adv
January 2025
Laboratory of Clean Low-Carbon Energy, Department of Thermal Science and Energy Engineering, University of Science and Technology of China Hefei 230023 PR China.
Crafting highly dispersed active metal sites on catalysts is an optimal method for improving the catalytic reactivity and stability, as it would improve atomic utilization efficiency, enhance reactant adsorption and activation ability through unique geometric and electronic properties. In this study, two synthesis methods were employed (ammonia evaporation (AE) and the impregnation method (IM)) to load Rh species onto the ZSM-5 support in order to attain tunable dispersivity, during which a 1.25-fold increase in the total yield of liquid oxygenated products (32 433.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Key Lab of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
ConspectusFor chemical reactions with complex pathways, it is extremely difficult to adjust the catalytic performance. The previous strategies on this issue mainly focused on modifying the fine structures of the catalysts, including optimization of the geometric/electronic structure of the metal nanoparticles (NPs), regulation of the chemical composition/morphology of the supports, and/or adjustment of the metal-support interactions to modulate the reaction kinetics on the catalyst surface. Although significant advances have been achieved, the catalytic performance is still unsatisfactory.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India.
Heterogeneous catalysts have emerged as a potential key for closing the carbon cycle by converting carbon dioxide (CO) into value-added chemicals. In this work, we report a highly active and stable ceria (CeO)-based electronically tuned trimetallic catalyst for CO to CO conversion. A unique distribution of electron density between the defective ceria support and the trimetallic nanoparticles (of Ni, Cu, Zn) was established by creating the strong metal support interaction (SMSI) between them.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemical and Biomolecular Engineering, National University of Singapore, 117585, Singapore.
Establishing optimized metal-support interaction (MSI) between active sites and the substrate is essential for modulating the adsorption properties of key reaction intermediates during catalysis, thereby enhancing the catalytic performance. In this study, catalyst composites with varying degrees of MSI are constructed using ruthenium (Ru) and different carbon nanotubes, and their performance for alkaline hydrogen evolution reaction (HER) is systematically investigated. Detailed kinetic assessments reveal that catalysts with a strong MSI exhibit superior HER activity.
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