| AVS 63rd International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Wednesday Sessions |
| Session HC+SS-WeM |
| Session: | Bridging Gaps in Heterogeneously-catalyzed Reactions |
| Presenter: | Donna Chen, University of South Carolina |
| Authors: | D.A. Chen, University of South Carolina A.S. Duke, University of South Carolina K. Xie, University of South Carolina A.J. Brandt, University of South Carolina T.D. Maddumapatabandi, University of South Carolina |
| Correspondent: | Click to Email |
The chemical activities of bimetallic Pt-Re clusters supported on TiO2(110) and single-crystal Pt-Re alloy surfaces are investigated as model systems for understanding Pt-Re catalysts in the water gas shift (WGS) reaction. The activities of these Pt-Re bimetallic surfaces are studied in a microreactor coupled to an ultrahigh vacuum chamber so that the surfaces can be characterized by X-ray photoelectron spectroscopy (XPS) before and after reaction. Bimetallic clusters consisting of a Re core covered by a Pt shell have turnover frequencies that are almost twice as high as that of the pure Pt clusters at 160 °C. Furthermore, the Re in the active bimetallic clusters remains in its metallic state because Re is not readily oxidized when it remains subsurface; there is no evidence that ReOx is active in promoting the WGS reaction. Pure Re clusters are not active for the WGS reaction, and bimetallic clusters with significant Re at the surface are less active than pure Pt clusters. Surface Re is oxidized under reaction conditions and sublimes as Re2O7. Post-reaction infrared spectroscopy studies show that CO and hydroxyls are detected on the surface.