This three-year award will support U.S.-France cooperative research in chemical engineering between John Falconer of the University of Colorado and Nicole Floquet of the Laboratory for Research of Solids at the University of Bourgogne. The investigators will study the properties of catalysts that selectively catalyze formation of dimethyldichlorosilane, a precursor to silicone polymers. The reaction of solid silicon and gaseous methyl chloride, which will be studied in this project, is the critical step in the production of silicone polymers. The U.S. investigator brings to this collaboration expertise in catalysis. This is complemented by the French investigator's expertise in solid-state analysis. Silicone polymers have wide applications in modern technology. They are used as sealants, lubricants, and hydraulic fluids. High-quality polymers require a pure monomer, in this case, dimethyldichlorosilane, and it is this issue that is addressed in the proposal.