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

Abstract

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.

Abstract

The pyrrolic N in Cu-np/NC composites can enhance the activation of H ₂O, resulting in excellent selectivity for CH ₄ and high current density.