Active Oxygenated Structure-Intensified CO 2 Capture Enables Efficient Electrochemical Ethylene Production Over Carbon Nanofibers.

The pursuit of high efficacy C-C coupling during the electrochemical CO 2 reduction reaction remains a tremendous challenge owing to the high energy barrier of CO 2 activation and insufficient coverage of the desired intermediates on catalytic sites. Inspired by the concept of capture-coupled CO 2 activation, we fabricated quinone-grafted carbon nanofibers via an in situ oxidative carbonylation strategy. The quinone functionality of carbon nanofibers promotes the capture of CO 2 followed by activation. At a current density of 400 mA cm -2 , the Faradaic efficiency of ethylene reached 62.9 %, and a partial current density of 295 mA cm -2 was achieved on the quinone-rich carbon nanofibers. The results of in situ spectroscopy and theoretical calculations indicated that the remarkable selectivity enhancement in ethylene originates from the quinone structure, rather than the electronic properties of Cu particles. The interaction of quinone with CO 2 increases the local *CO coverage and simultaneously hinders the co-adsorption of *H on Cu sites, which greatly reduces the energy barrier for C-C coupling and restrains subsequent *CO protonation. The modulation strategy involving specific oxygenated structure, as an independent degree of freedom, guides the design of functionalized carbon materials for tailoring the selectivity of desired products during the CO 2 capture and reduction.