Electrochemical reduction of CO₂ to multi-carbon chemicals over Cu-derived catalysts is currently restricted by the low faradaic efficiency (FE) and production rate of C₂₊ products. Here, we report tandem gas diffusion electrodes yielding C₂₊ products at simultaneously high FE and production rate via sequential CO₂ reduction on two independent, selective, and adjacent catalyst layers. The tandem electrodes possess the intrinsic benefits of lower onset potential and higher partial current densities of C₂₊ products compared to bare copper electrodes. Through balancing the CO generation and consumption rates, the FEs of both C₂₊ products and C₂H₄ for tandem electrodes can be maximized to exceed those for bare copper electrodes. The optimized Cu/Ni-N-C tandem electrode, which comprises sequential Cu and Ni-N-C catalyst layers, reaches FE of 62% and partial current density of 415 mA cm⁻² for C₂H₄ at −0.70 V versus RHE.

目前，低法拉第效率（FE）和C ₂₊产品的生产率限制了用Cu衍生的催化剂将CO ₂电化学还原为多碳化学物质。在这里，我们报告了串联气体扩散电极，通过在两个独立的，选择性的和相邻的催化剂层上进行连续的CO ₂还原，可以同时以高FE和高生产率获得C ₂₊产物。与裸铜电极相比，串联电极具有C ₂₊产品较低的起始电势和较高的部分电流密度的固有优势。通过平衡CO的产生和消耗速率，C ₂₊产品和C ₂ H ₄的FE均串联电极的最大数量可以超过裸铜电极的最大数量。相对于RHE，对于C ₂ H ₄，包括顺序的Cu和Ni-NC催化剂层的优化Cu / Ni-NC串联电极达到FE为62％，分流密度为415 mA cm ^-2。