Due to the growing demand for energy and impending environmental issues, fuel cells have attracted significant attention as an alternative to conventional energy technologies.

As a promising and important carbon source, utilization of carbon dioxide (CO₂) can effectively solve the energy crisis caused by fossil resource consumption and the environmental problems arising from the emission of CO₂.

Fuel cell is an electrochemical device, which can directly convert the chemical energy of fuel into electric energy, without heat process, not limited by Carnot cycle, high energy conversion efficiency, no noise and pollution.

The systematic summarization of synthesis–structure–property–mechanism correlations provides guidance for the rational design of an atomically dispersed M–N–C catalyst for the ORR.