Double Tuning of the Local Environment on Cu Nanoparticles Towards Enhanced C2+ Selectivity.

Electrochemical reduction of carbon dioxide into multi-carbon products provides a scheme to synthesize high value-added feedstocks and carbon-based fuels via renewable electricity, which has attracted wide attention. At present, Cu is one of the promising materials for electro-catalyzing CO2 to multi-carbon products. However, the product distribution of Cu catalysts is relatively wide. Here, boron (B)-doped Cu nanoparticles (NPs) with plentiful defects is prepared, which synergistic effects work together to regulate the local environment on the electrode surface, thereby effectively promoting the reduction of carbon dioxide to multicarbon (C2+) products in the neutral electrolyte. Especially, the enhanced local environment increases the *CO intermediate and OH- adsorption, which in turn reduces the energy barrier of the CC coupling step. The results reveal that C2+ Faradaic efficiency (FE) of boron-doped Cu NPs (B-Cu-1) is approximately 75% and the stability is up to 30 h at -1.1 V (vs. RHE). Density functional theory calculations further make it clear that the B-induced defects and Cuδ+ increase the adsorption of *CO intermediate, favoring the C2+ pathways. This work paves a simple and effective method for promoting C2+ production through double tuning of the local environment during CO2 reduction reaction (CO2RR).