▎ 摘　　要

Inspired by the recent experimental synthesis of graphene nanoribbons (GNRs) and theoretical research on their edge-decoration, we comprehensively studied the electrocatalytic performance of GNRs edge-decorated with Cu for CO2 reduction. Compared to zigzag GNRs, the Cu-terminated armchair GNRs with a width of n = 3p + 2 were more efficient catalysts for producing methanol from CO2 with a free energy barrier of less than 0.5 eV, offering the advantages of a lower overpotential and higher selectivity than bulk Cu and other graphene-supported Cu structures. On the other hand, the competing hydrogen evolution reaction could be effectively suppressed by Cu-terminated armchair GNRs. Hence, the edge-decorated GNRs offer great flexibility for tuning the catalytic efficiency and selectivity for CO2 electroreduction.