Low-Temperature Direct Electrochemical Methanol Reforming Enabled by CO-Immune Mo-based Hydrogen Evolution Catalysts

Hydrogen storage in the form of intermediate artificial fuels such as methanol is important for future chemical and energy applications, and the electrochemical regeneration of hydrogen from methanol is thermodynamically favorable compared to direct water splitting. However, CO produced from methanol oxidation can adsorb to H 2 evolution catalysts and drastically reduce catalyst activity. In this study, we report and explore the origins of CO immunity in Mo-containing H 2 evolution catalysts. Unlike conventional catalysts such as Pt or Ni, Mo-based catalysts display remarkable immunity to CO poisoning. The origin of this behavior in NiMo appears to arise from the apparent inability of CO to bind Mo in electrocatalytic conditions, with mechanistic consequences for the HER in these systems. This specific property of Mo-based HER catalysts makes them ideal in environments where poisons may be present.