Nitrogen Defects in Porous Carbons with Adjacent Silver Nanoclusters for Efficient CO2 Reduction

Abstract

AbstractElectrochemical CO2 reduction is an environmentally sustainable way for CO2 conversion and utilization, the development of which needs highly efficient catalysts. Ag‐based materials are one kind of electrocatalyst that are catalytically active for CO2 reduction to CO. In this work, Ag clusters were fabricated on nitrogen‐doped porous carbon nanomaterials by a high‐temperature annealing method. The well‐dispersion of Ag sites on nitrogen‐doped carbons (Ag/NC) promoted CO production. As a result, Ag/NC showed a maximum Faradaic efficiency of 94 % at −0.7 V versus reversible hydrogen electrode (vs RHE) at room temperature. In addition, Ag/NC showed good CO2 reduction stability, and the CO Faradaic efficiency remained stable at about 90 % at −0.7 V vs RHE for 12 h. Density functional theory calculation indicated that the cooperation of Ag and N‐dopings effectively reduced the activation energy barrier of CO2 reduction relative to hydrogen evolution reaction and thus effectively promoted the electrocatalytic reduction of CO2 molecules to CO. This method provides a new idea for the synthesis of CO2 reduction catalysts with higher activity, selectivity and stability.