9224318 Robert Kuntz This is an investigation of the influence structure and bonding of molybdenum-sulfur complexes on the efficiency and mechanism of the photocatalytic reduction of acetylene or water. The electrons for these reductions come from band-gap irradiation of small-particle titania suspensions which serve as a "support" for the molybdenum complexes. Specific catalysts studied include monomeric and dimeric forms of molybdenum(V) and molybdenum(VI) with ligands containing sulfur and/or oxygen. An objective is the identification of the species exhibiting high efficiency for trapping conduction-band electrons and catalyzing reduction of small molecules. Isotherms for adsorption and structures of adsorbed species are investigated for various molybdenum-sulfur solution species using ultraviolet and Raman spectroscopies; the studies are done in solution or on solid surfaces in contact with solution. Similar studies are done after irradiation, including the examination of substrates and the determination of the oxidation state of the catalyst by chemical methods. The use of light-driven catalysts (photocatalysis) offers the potential to convert abundant and inexpensive materials to useful products. Better understanding to improve efficiency is needed, but these processes offer relatively cheap routes to some valuable products. They will also reduce fossil fuel consumption (especially when solar radiation can be used) and be environmentally benign.
