Exploration of earth-abundant transition metals (Fe, Co, Ni) doped on W18O49 system as electrocatalysts for urea productiont

The conversion of inert N-2 and CO2 into urea by electrocatalytic technology not only reduces the cost of urea synthesis in future, but also alleviates the environmental pollution problem caused by carbon emission in traditional industrial production. However, facing downside factors such as strong competitive reactions and unclear reaction mechanism, the design of high-performance urea catalysts is imminent. This study demonstrates that W18O49 system doped heteronuclear metals (TM = Fe, Co, Ni) can effectively solve the problem of competitive adsorption between N-2 and CO2 and realize the co-adsorption of N-2 and CO2 at diverse sites. Their theoretical limiting voltages for urea production on TM-W18O49 (TM = Fe, Co, Ni) systems are -0.46 V, -0.42 V and -0.52 V, respectively. The results are all lower than that of the contrastive voltage in pristine W18O49 system (-0.91 V), further indicating the rationality and necessity of single-atom doped strategy for the co-reduction of two molecules. Specially, Co-W18O49 can theoretically inhibit the side reactions of NRR, CO2RR, and HER, which deserve future experimental exploration in future. The study suggests that doping heteronuclear metal into transition metal oxides is a feasible scheme to solve competitive adsorption and improve catalytic performance.