Advances in Physical Mixture Catalysts as a Heterogeneous Catalytic Strategy: A Review

Metal alloys are widely recognized for their high catalytic activity in the field of heterogeneous catalysis. This enhanced performance arises from various alloying effects between the constituent atoms within multimetallic particles. Recently, our research group discovered that physically separating metals from their alloyed state and forming a physical mixture can further enhance catalytic performance across a range of reactions, including thermochemical and electrochemical processes. In this catalytic system, each type of metal serves as an active site for a distinct subreaction. These subreactions are effectively coupled through the intimate contact between catalytic components, which facilitates the transfer of reaction intermediates across the carbon support. In this review, we discuss recent advances in understanding this catalytic effect, with special interest in thermocatalysis and electrocatalysis. While significant progress has been made in improving reaction rates, future research should also focus on enhancing product selectivity and expanding the application of this approach to photochemical reactions.