Synthesis of Supported Bimetal Catalysts using Galvanic Deposition Method

Abstract

Supported bimetallic catalysts have been studied because of their enhanced catalytic properties due to metal-metal interactions compared with monometallic catalysts. We focused on galvanic deposition (GD) as a bimetallization method, which achieves well-defined metal-metal interfaces by exchanging heterogeneous metals with different ionisation tendencies. We have developed Ni@Ag/SiO₂ catalysts for CO oxidation, Co@Ru/Al₂ O₃ catalysts for automotive three-way reactions and Pd-Co/Al₂ O₃ catalysts for methane combustion by using the GD method. In all cases, the catalysts prepared by the GD method showed higher catalytic activity than the corresponding monometallic and bimetallic catalysts prepared by the conventional co-impregnation method. The GD method provides contact between noble and base metals to improve the electronic state, surface structure and reducibility of noble metals.

Keywords: Bimetallic catalysts; Galvanic deposition; Heterogeneous catalysts.