Dr. Harry Gafney, Department of Chemistry, CUNY Queens College, is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program of the Chemistry Division for the assembly of mulitcomponent catalytic sites in porous silica matrices for the photocatalyzed conversion of carbon dioxide to methane with visible light. The photocatalyzed conversion of carbon dioxide to methane, an eight-electron reduction, can occurs when carbon dioxide adsorbs onto an "activating site" in a silica matrix, and nearby photoactivated tungsten oxide transfers the reducing equivalents and hydrogen from coadsorbed water. This project aims at determining how adsorption activates carbon dioxide, and how the reaction, currently driven by <310-nm light, can be driven with visible light. It will determine if the shifts to longer wavelength that accompany metal oxide particle growth within the silica matrices occur with a corresponding shift in the photoaction spectrum. The silica matrices will be tailored to increase the number of carbon dioxide activating sites . Energy conversion and greenhouse gas emissions are societal concerns that must be addressed. Methane is being more widely used as a fuel, particularly in urban public transit systems. This application examines photocatalytic systems that utilize visible light to convert carbon dioxide to methane thereby amplifying energy output while minimizing greenhouse gas emission. The project also will serve to educate and train undergraduate, graduate, and postdoctoral students.
