| AVS 65th International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Tuesday Sessions |
| Session HC+SS-TuM |
| Session: | Nanochemistry in Heterogeneous Catalysis |
| Presenter: | Timothy Gorey, University of Utah |
| Authors: | T. Gorey, University of Utah E. Baxter, University of Utah A. Cass, University of Utah S. Anderson, University of Utah B. Zandkarimi, University of California at Los Angeles A. Alexandrova, University of California at Los Angeles |
| Correspondent: | Click to Email |
Size-selected cluster catalysts are powerful tools that enable us to probe and characterize specific catalytic reaction mechanisms controlled by the particle’s size. By combining deposition of atomically-selected Pt clusters, with ALD to selectively add Sn atoms to the clusters, we obtain Pt-Sn alloy clusters with exactly known numbers of Pt atoms, and a narrow distribution of Sn atoms. In addition to being a powerful experimental tool, having size-selected model catalysts with well-defined compositions allow detailed theoretical simulations, providing insight into cluster structure, and the mechanistic origins of the size and alloying effects observed experimentally. It is found that tin alloying has a large and beneficial effect on both the branching between intact ethylene desorption vs. dehydrogenation/carbon deposition, and on the thermal stability of the clusters at temperatures to 700 K. Theoretical predictions for the structures and electronic properties of the thermally accessible ensemble of isomers are used to rationalize the observed effects in detail.
*Work supported by the United States Air Force Office of Scientific Research (AFOSR FA9550-16-1-0141)