Highly Dispersed Copper over β-Mo2C as an Efficient and Stable Catalyst for the Reverse Water Gas Shift (RWGS) Reaction

Cu-oxide catalysts have a tendency to deactivate dramatically in reverse water gas shift (RWGS) reaction, because of the aggregation of supported copper particles at high temperatures. Herein, β-Mo2C, which is a typical type of transition-metal carbide, has been demonstrated to be capable of dispersing and stabilizing copper particles. Cu/β-Mo2C catalysts exhibit good catalytic activity and stability for the RWGS reaction. Under relatively high weight hourly space velocity (WHSV = 300 000 mL/g/h), the optimized 1 wt % Cu/β-Mo2C exhibits superior activity over traditional oxide-supported Pt- and Cu-based catalysts. The activity was well-maintained in a 40 h stability test, and the catalyst shows stable reactivity in a six-cycle start-up cool-down experiment. Detailed structure characterizations demonstrate that the strong interaction between Cu and β-Mo2C effectively promotes the dispersion of supported copper and prevents the aggregation of Cu particles, which accounts for the extraordinary activity and stability for the RWGS reaction.