Solid phase microwave-assisted fabrication of Fe-doped ZIF-8 for single-atom Fe-N-C electrocatalysts on oxygen reduction

Abstract Fe–N–C endowed with inexpensiveness, high activity, and excellent anti-poisoning power have emerged as promising candidate catalysts for oxygen reduction reaction (ORR). Single-atom Fe–N–C electrocatalysts derived from Fe-doped ZIF-8 represent the top-level ORR performance. However, the current fabrication of Fe-doped ZIF-8 relies on heavy consumption of time, energy, cost and organic solvents. Herein, we develop a rapid and solvent-free method to produce Fe-doped ZIF-8 under microwave irradiation, which can be easily amplified in combination with ball-milling. After rational pyrolysis, Fe–N–C catalysts with atomic FeN4 sites well dispersed on the hierarchically porous carbon matrix are obtained, which exhibit exceptional ORR performance with a half-wave potential of 0.782 V (vs. reversible hydrogen electrode (RHE)) and brilliant methanol tolerance. The assembled direct methanol fuel cells (DMFCs) endow a peak power density of 61 mW cm−2 and extraordinary stability, highlighting the application perspective of this strategy.