Highly efficient ampere-level CO2 reduction to multicarbon products via stepwise hollow-fiber penetration electrodes

Efficient C2+ production from CO2 electrocatalytic reduction exhibits significant promise but suffers from low selectivity and undesired side reactions. Stepwise electroreductions of CO2 to CO and then to C2+ products can benefit from the perfect cooperation of the first high CO production efficiency and the subsequent favorable C-C coupling kinetics of CO. Herein, by virtue of serial Ag and Cu hollow-fiber penetration electrodes, a high-efficiency CO2 electroreduction to C2+ products is achieved with a partial current density of 1.8 A cm−2 and a faradaic efficiency of 90.5 %. Experimental results and density functional theory calculations demonstrate that the synergetic combination of unique penetration effect induced by hierarchical micro/nanostructured hollow fiber configurations and regulated electronic structures by chloride ion adsorption, is responsible for the superior activity. This work provides a facile tactic and encouraging headway to design applicable efficient CO2 electrocatalytic reduction systems towards high-value C2+ chemicals.