| Affiliation: | 1. CNR-ICCOM & IPCF, Consiglio Nazionale delle Ricerche, Pisa, Italy;2. Materials Science Division, Argonne National Laboratory, Lemont, IL, USA;3. Harish-Chandra Research Institute, HBNI, Jhunsi, Allahabad, India;4. Institut für Physik, Universit?t Rostock, Rostock, Germany;5. X-ray Science Division, Argonne National Laboratory, Lemont, IL, USA;6. Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-, India;7. East Tokyo Laboratory, Genesis Research Institute, Inc., Ichikawa, Chiba, Japan;8. Cluster Research Laboratory, Toyota Technological Institute: in, East Tokyo Laboratory, Genesis Research Institute, Inc. Ichikawa, Chiba, Japan;9. Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, USA;10. Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA;11. Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA, USA |
| Abstract: | A combined experimental and theoretical investigation of Ag‐Pt sub‐nanometer clusters as heterogeneous catalysts in the CO→CO2 reaction (COox) is presented. Ag9Pt2 and Ag9Pt3 clusters are size‐selected in the gas phase, deposited on an ultrathin amorphous alumina support, and tested as catalysts experimentally under realistic conditions and by first‐principles simulations at realistic coverage. In situ GISAXS/TPRx demonstrates that the clusters do not sinter or deactivate even after prolonged exposure to reactants at high temperature, and present comparable, extremely high COox catalytic efficiency. Such high activity and stability are ascribed to a synergic role of Ag and Pt in ultranano‐aggregates, in which Pt anchors the clusters to the support and binds and activates two CO molecules, while Ag binds and activates O2, and Ag/Pt surface proximity disfavors poisoning by CO or oxidized species. |
