Regulation mechanism of nanotwin on selective CO dimerization pathway into C2 products

The surface environment plays an indispensable role in the electrocatalysis of the CO2 reduction reaction (CO2RR). Being one of the V-shaped nanotwins, the Cu n-ary sumation 3(111) nanotwin boundary (NTB) features two junctions of NTB with the (111) surface, designated as the summit and valley, leading to more relaxed structural fields. In contrast to the ideal Cu (111) surface, the d-band center of Cu situated on the summit position of 6NTB is shifted to the Fermi level by 0.11 eV, thus modifying the adsorption capacity. Sequentially, the CO dimerization is strongly focused on the summit position (01-02 site pair), revealing a synergistic effect. The mechanism provides an explanation for the detection of eight possible C-C coupling pathways. Furthermore, these findings disclose dissimilarities in the activity of Cu (111) and NTB-(111) with respect to C2 products, and provide new ideas for the mechanistic studies of the copper-catalyzed CO2RR.