In situ nanostructuring and stabilization of polycrystalline copper electrodes with organic salt additives promotes CO_2 reduction to ethylene

Abstract

The electrocatalytic conversion of CO₂ to hydrocarbons using renewable energy provides a sustainable pathway to produce carbon-neutral fuels and value-added chems. However, a great challenge remains to develop efficient and robust electrocatalysts with high selectivity profile for any single product, at low overpotential. To this end, nanostructured copper electrodes have shown enhanced selectivity for C-C coupled products during CO₂ electroredn. reaction (CO₂RR). Nevertheless, inexpensive means to maintain structural stability during catalysis remain a challenge to sustained activity and selectivity. Herein, we report the combination of polycryst. copper and pyridinium-based additives as a simple system to achieve and maintain high selectivity of up to 60-70 % for C≥2 products, for 43h, in 0.1M KHCO₃. Several roles have been demonstrated for the org. additive, including: the formation of "nanocube-like" nanostructures by corrosion of the copper surface; the stabilization of the nanostructures during catalysis by formation of a protective org. layer; and the promotion of C≥2 products. Overall, this simple and cheap technic opens promising opportunities in preserving nanostructures during catalysis and could be applied to many systems already reported in the literature.

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