Kim Hyun You, Henkelman Graeme
Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-0165, United States.
J Phys Chem Lett. 2012 Aug 16;3(16):2194-9. doi: 10.1021/jz300631f. Epub 2012 Jul 31.
DFT+U calculations of CO oxidation by Au13 nanoclusters (NCs) supported on either CeO2 or doped (X-Ce)O2 (X = Au, Pt, Pd, Ti, Ru, Zr) show that doping the CeO2 support accelerates CO oxidation by the Mars-van Krevelen mechanism at the Au-(X-Ce)O2 interface. We find that Au, Pd, Pt, and Ti dopants significantly lower the vacancy formation energy of the CeO2 support and that electron donation from the supported Au13 NC shifts the vacancy formation energy of (X-Ce)O2 and determines the final vacancy formation energy of Au13@(X-Ce)O2. The vacancy formation energy of Au13@(X-Ce)O2 is a good reactivity descriptor for CO oxidation at the Au-(X-Ce)O2 interface and a screening factor for dopant selection. Our results confirm that the catalytic activity of oxide-supported Au catalysts can be modified by the chemical composition of the support and suggest that chemical modification of the oxide support is promising for the optimization of oxidation catalysis by supported Au NCs/nanoparticles.
对负载在CeO₂或掺杂（X-Ce）O₂（X = Au、Pt、Pd、Ti、Ru、Zr）上的Au₁₃纳米团簇（NCs）进行的CO氧化的DFT+U计算表明，掺杂CeO₂载体通过Mars-van Krevelen机制在Au-(X-Ce)O₂界面加速了CO氧化。我们发现，Au、Pd、Pt和Ti掺杂剂显著降低了CeO₂载体的空位形成能，并且负载的Au₁₃ NC的电子给予改变了（X-Ce）O₂的空位形成能，并决定了Au₁₃@(X-Ce)O₂的最终空位形成能。Au₁₃@(X-Ce)O₂的空位形成能是Au-(X-Ce)O₂界面CO氧化的良好反应性描述符和掺杂剂选择的筛选因子。我们的结果证实，氧化物负载的Au催化剂的催化活性可以通过载体的化学成分进行调节，并表明氧化物载体的化学修饰对于优化负载的Au NCs/纳米颗粒的氧化催化具有前景。
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