Enhancing CO 2 electroreduction to CH 4 over Cu nanoparticles supported on N-doped carbon.

The electroreduction of CO 2 to CH 4 has attracted extensive attention. However, it is still a challenge to achieve high current density and faradaic efficiency (FE) for producing CH 4 because the reaction involves eight electrons and four protons. In this work, we designed Cu nanoparticles supported on N-doped carbon (Cu-np/NC). It was found that the catalyst exhibited outstanding performance for the electroreduction of CO 2 to CH 4 . The FE toward CH 4 could be as high as 73.4% with a high current density of 320 mA cm -2 . In addition, the mass activity could reach up to 6.4 A mg Cu -1 . Both experimental and theoretical calculations illustrated that the pyrrolic N in NC could accelerate the hydrogenation of *CO to the *CHO intermediate, resulting in high current density and excellent selectivity for CH 4 . This work conducted the first exploration of the effect of N-doped species in composites on the electrocatalytic performance of CO 2 reduction.