Mutual promotion effect of Ni and Mo2C encapsulated in N-doped porous carbon on bifunctional overall urea oxidation catalysis

Abstract Efficient hydrogen production from water splitting was crucial for sustainable energy society and yet impeded by sluggish anodic water oxidation and urea oxidation had been considered as alternative reaction due to the much lower oxidation potential. Rational design of highly efficient cost-effective electrocatalysts for urea oxidation was therefore urgent for the development of hydrogen production from overall urea oxidation. Herein, the Ni/Mo2C@CN catalyst consisted of porous carbon shell and heterojunction Ni/Mo2C core was constructed by an in-situ self-confinement synthesis strategy. The mutual promotion effect of Ni and Mo2C can boost the urea oxidation and hydrogen evolution reactions at the same time. Only 1.51 V applied potential was needed to achieve stable 10 mA/cm2 overall urea oxidation on the Ni/Mo2C@CN catalyst. By considering the great stability resulted from the protection effect of the carbon shell, practical application potential of Ni/Mo2C@CN in overall urea oxidation was achieved.