Amorphous N_xC Coating Promotes Electrochemical CO₂ Deep Reduction to Hydrocarbons over Ag Nanocatalysts

The electrochemical conversion of CO₂ into high value-added hydrocarbon products provides a promising path to reduce the dependence on fossil energy and close carbon cycle. Cu-based catalyst is so far the only material that can effectively realize this process, limiting the optional catalysts for industrial application. Therefore, it is urgent to design other strategies to boost hydrocarbon products beyond Cu-based materials. Here, the N_xC shell is constructed on the surface of Ag nanoparticle core (core–shell structure Ag@N_xC) to boost the formation of CH₄ and CH₂CH₂. The N_xC shell does not modify the electronic property of Ag but prolongs the residence time of the CO intermediate to enhance the C–C coupling and deep reduction, which are proved by in situ ATR-SEIRAS. In addition, the activated H₂O molecules could provide sufficient adsorbed H to enhance the further reduction of the carbonaceous intermediate during the CO₂ reduction reaction. As a result, the Faradaic efficiency (FE) of the hydrogen evolution reaction is enhanced over the Ag@N_xC-2 catalyst (∼12% at −1.4 V vs RHE), and the FEs of CH₄ and CH₂CH₂ are significantly enhanced (above 43.8 and 8.4%, respectively). Our findings provide a strategy to achieve the conversion of CO₂ into hydrocarbon products over non-Cu-based catalysts.