(97d) Preparation of Silver-Platinum Bimetallic Catalysts Via Electroless Deposition

Bimetallic catalysts are typically prepared using either successive impregnation or co-impregnation of the metallic catalyst, which leases to the formation of individual supported metals as well as bimetallic catalysts. An alternative approach for the preparation of bimetallic catalysts is the use of electroless deposition (ED) of reducible metal salts onto other metals. ED is a process for the deposition of metallic components by a controlled chemical reaction that is catalyzed by the pre-existing metal (catalysis) or the metal which is being deposited (auto-catalysis). In this study electroless deposition of Ag is carried out using an aqueous bath containing HCHO as the reducing agent, AgNO3 as the reducible metal salt, and Pt (as Pt/SiO2) as the pre-existing metal. Final Ag weight loadings are a function of AgNO3, HCHO, and concentration of surface Pt sites. A working rate equation that relates the rate of deposition of the Ag onto Pt surfaces using the above variables has been developed. Preliminary kinetic evaluation of these catalysts for the hydrogenation of 3,4 epoxy-1-butene will be discussed.