Operando Synthesis of High-Curvature Copper Thin Films for CO(2) Electroreduction

As the sole metal that could reduce CO(2) to substantial amounts of hydrocarbons, Cu plays an important role in electrochemical CO(2) reduction, despite its low energy efficiency. Surface morphology modification is an effective method to improve its reaction activity and selectivity. Different from the pretreated modification method, in which the catalysts self-reconstruction process was ignored, we present operando synthesis by simultaneous electro-dissolution and electro-redeposition of copper during the CO(2) electroreduction process. Through controlling the cathodic potential and CO(2) flow rate, various high-curvature morphologies including microclusters, microspheres, nanoneedles, and nanowhiskers have been obtained, for which the real-time activity and product distribution is analyzed. The best CO(2) electro-reduction activity and favored C(2)H(4) generation activity, with around 10% faradic efficiency, can be realized through extensively distributed copper nanowhiskers synthesized under 40 mL/min flow rate and −2.1 V potential.