Confinement and interface engineering of CuSiO3 nanotubes for enhancing CO2 electroreduction to C2+ products

Electrochemical CO 2 reduction (ECR) to C 2+ products is an efficient method to accomplish intermittent energy storage and CO 2 utilization. Developing high-selectivity electrocatalysts for C 2+ products, especially C 2+ alcohols, have attracted more attention but still remains a major challenge. Here, three kinds of short nanotube (<100 nm), long nanotube (>100 nm), and long nanotube-assembled hollow sphere CuSiO 3 catalysts with different confined space are fabricated for boosting the ECR to produce C 2+ products selectivity. Long CuSiO 3 nanotubes exhibit a higher yield of C 2+ alcohols (26.8 %) and more satisfactory Faraday efficiency (FE) of 69.5 % for C 2+ products than short nanotubes and nanotube-assembled hollow spheres. The confinement effect of long CuSiO 3 nanotubes is conducive to promoting the dimerization of the key reaction intermediate (*CO), inhibiting the diffusion of protons and the side-reaction hydrogen evolution reaction (HER). The formed Cu 0 /Cu + interfaces in CuSiO 3 nanotubes promote the dimerization reactions of adsorbed *CO. The synergistic effect of nanotubes confinement and Cu 0 /Cu + interfaces facilitate the C C coupling reaction to C 2+ products via ECR.