文摘
Development of a high-performance electrocatalyst for an oxygen reduction reaction with a low-cost bulk production method is crucial for practical applications of metal–air batteries, oxygen sensors, fuel cells, and so on. Here, we developed a bulk production method for nitrogen- and ferrum-doped nanoporous carbon microspheres as a high-performance ORR catalyst. The process involved hydrothermal carbonization of starch with iron ions as catalysts to catalyze the formation of carbon spheres and annealing the carbon spheres in an NH<sub>3sub> atmosphere. NH<sub>3sub> was used not only as the nitrogen source to form the N-doped carbon material but also to etch the carbon to produce a nanoporous carbon material, which has high surface area and pore volume. As a highly available, accessible, and recyclable biomass, starch can be used to achieve a cheap electrocatalyst. The proposed approach is simple and scalable. The typical product has excellent activity in alkaline media and high activity in acidic media. The typical product is a competitive substitution for commercial Pt/C in a zinc–air battery. This work proposes a new design strategy for bulk production of the excellent nonprecious metal catalysts from cheap biomass.