Metal overlayer on metal carbide substrate: unique bimetallic properties for catalysis and electrocatalysis

Transition metal carbides often display electronic and catalytic properties that are similar to Pt-group metals. In this tutorial review, we describe the feasibility of replacing the Pt-group metal component in bimetallic systems with metal carbides. By supporting a metal monolayer on a carbide substrate, these bimetallic surfaces exhibit similar catalytic and electrocatalytic activity to the corresponding Pt-based bimetallic systems while demonstrating the advantages of lower cost and higher thermal stability. Another promising aspect is that the carbide substrates often promote the formation of small, flat metal particles with novel catalytic properties. We review the synthesis, characterization, and utilization of carbide-supported metal surfaces in heterogeneous catalysis and electrocatalysis. An overview is given for both theoretical and experimental investigations, and trends are drawn from the literature. We also discuss opportunities for future research on carbide-supported metal surfaces.