Sustainable conversion of natural gas to hydrogen using transition metal carbides

CH4 is a H-rich compound and can be considered as a source of H2, but all the CH4 reforming-based H2 production reactions are highly endothermic in nature. So, using a catalyst becomes compulsory for the economic feasibility of the H2 produced by CH4 reforming. However, the applied catalysts become inactive due to coke deposition, oxidation, and metal sintering. TMCs resist coke formation and have a high affinity toward the oxides. TMCs also possess noble-metal like electronic properties and surface catalytic behavior. All these characteristics make TMCs the potential candidates for catalyzing CH4 reforming-based H2 production reactions. This review focuses on the use of Mo2C and WC, the two important TMCs, for catalyzing CH4 reforming-based H2 production reactions, with special emphasis on the challenges involved, and strategies adopted to improve the catalytic role of TMCs by engineering the precursor and synthesizing method/conditions (use different precursors, synthesizing methods and process conditions), structure (designing a dual M-MC (M = metal) active site by adding a promoter, and in-addition using support), and reaction conditions. This review will also guide for designing an efficient TMC catalyst for catalyzing CH4 reforming-based H2 production reactions, for achieving future research goals.