Rh-Mo bimetallic cluster-derived catalysts for CO hydrogenation
- Univ. of Delaware, Newark, DE (United States)
Recent investigations in the catalytic chemistry literature have focused on molybdenum promoted rhodium catalysts with particular emphasis on organometallic-derived Rh-Mo catalysts. The intention of this present work is to develop Rh-MNo bimetallic catalysts using Rh/Mo bimetallic clusters as precursors. Preliminary investigation of CpMoRh(CO){sub 3}(PPh{sub 3}){sub 2}-derived Rh-Mo/Al{sub 2}O{sub 3} and Rh-Mo/SiO{sub 2} catalysts are reported. While the catalysts tested thus far have somewhat lower activities for CO hydrogenation than other Mo-promoted Rh catalysts in the literature, these catalysts indeed exhibit superior oxygenate selectives. This special selectivity of the cluster-derived bimetallic catalyst may be related to the following factors: (1) Molybdenum promotion, as has been confirmed by many researchers, can increase activity and improve the oxygenate selectivity; (2) A strong Rh-Mo bond in the precursor, which may be a double bond as evidenced by its short bond length (2.588{angstrom}), might be maintained to some extent in the derived catalyst and promote Rh more effectively; (3) Phosphorus present on the surface, while often considered to be an inhibitor to metallic catalysts, may block some active sites on the surface for hydrocarbon formation and decrease hydrocarbon selectivity. Furthermore, phosphorus oxide, if present, can be an acidic promotor and could influence the formation of oxygenate (4) Inherent acid-base properties of the supports.
- OSTI ID:
- 141303
- Report Number(s):
- CONF-930304--
- Country of Publication:
- United States
- Language:
- English
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