Degradation: A critical challenge for M–N–C electrocatalysts

Atomically dispersed transition metal (M) and nitrogen (N) co-doped carbon (M–N–C) electrocatalysts hold excellent application potentials for several critical reactions required in electrochemical conversion processes and energy storage devices, including oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. Despite significant progress achieved in the past few decades, their commercialization is hindered by their fast degradation. This perspective article outlines the historical development of M–N–C electrocatalysts, the current understanding of their active catalytic sites, and crucial degradation mechanisms. We highlight that many methods used to tailor M–N–C electrocatalysts likely cause contradictory effects on activity and stability. More emphasis is needed to address their degradation issues under industry-relevant working conditions.