Bulk Production of Nonprecious Metal Catalysts from Cheap Starch as Precursor and Their Excellent Electrochemical Activity

Abstract

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 NH3 atmosphere. NH3 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...