Promotion of CO₂ Electrochemical Reduction via Cu Nanodendrites

The electrochemical conversion of carbon dioxide (CO2) to fuels and chemicals is an opportunity for sustainable energy research that can realize both renewable energy storage and negative carbon cycle feedback. However, the selective generation of multicarbon products is challenging because of the competitive hydrogen evolution reaction (HER) and protonation of the reacting adsorbate. Copper-based materials have been the most commonly studied catalysts for CO2 electroreduction due to their ability to produce a substantial amount of C2 products. Here, we report that a nanodendrite configuration can improve the electrocatalytic performance of Cu catalysts, especially multicarbon product formation, while suppressing HER and methane production. The abundant conductive networks derived from the fractal copper dendritic structures with a high electrochemically active surface area (ECSA) facilitate electron transport and mass transfer, leading to superior kinetics for the formation of multicarbon products from CO2 electroreduction. As a result, approximately 70–120% higher ethylene and 60–220% higher C3 (n-PrOH and propanal) yields with lower onset potentials were produced over Cu nanodendrites compared to the initial Cu particles. This work opens an avenue for promoting CO2 electrochemical reduction to multicarbon products by catalyst configuration modulation.