Designing Non-Precious Metal M–N/C Electrocatalysts for Renewable Energy Conversion Reactions

Abstract

Non-precious metal catalysts (NPMCs) have emerged as alternatives to expensive precious metal (Pt, Ir, or Ru) based electrocatalysts in renewable energy conversion reactions, including oxygen reduction reaction (ORR). Among various NPMCs, M–N/C (M = transition metal) catalysts have been suggested as the most promising class of NPMCs, owing to their high catalytic activity. In this presentation, we show our recent efforts toward M–N/C ORR electrocatalysts. We developed a general design strategy based on “silica-protective-layer-assisted” method that can preferentially generate ORR-active Fe–Nx sites towards highly efficient Fe–N/C electrocatalysts. The prepared Fe–N/C catalysts showed excellent ORR activity in alkaline and acidic electrolytes, and demonstrated high current and power densities for both acidic and alkaline polymer electrolyte fuel cells. In addition, the synthetic strategy was extended to Co–N/C and Ni–N/C catalysts, which respectively demonstrated promises in hydrogen evolution reaction and CO2 reduction reaction.