Aluminum-Doped Mesoporous Copper Oxide Nanofibers Enabling High-Efficiency CO2 Electroreduction to Multicarbon Products

Copper is the most promising catalyst for the electrocatalytic conversion of CO2 into multicarbon (C2+) products but it is often plagued by low selectivity and productivity. Here, we report that aluminum (Al)-doped mesoporous copper oxide nanofibers (Cu-Al MONFs) can exhibit excellent performance in the electrocatalytic reduction of CO2 to C2+ products, with the remarkable C2+ Faradaic efficiency of 76.4% at a high current density of 600 mA cm–2. In sharp contrast, the comparative CuO nanofibers exhibit extremely severe hydrogen evolution (FE up to ∼70%) and limited C2+ products under the same condition. Detailed investigations indicate that the introduction of Al not only induces the formation of a mesoporous structure during the etching process but also adjusts the electronic structure of Cu via doping, which optimize the intermediate binding and C–C coupling on the Cu-Al MONFs. This work provides new inspiration for exploring high-performance Cu-based materials for electrocatalytic reduction of CO2.