The promise and challenge of electrochemical mitigation of CO₂ calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO₂ electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO₂ conversion to CO and HCOO^–. With a cobalt phthalocyanine-based cathode catalyst, the CO-selective cell starts to operate at a 0.26 V overpotential and reaches a Faradaic efficiency of 94% and a partial current density of 31 mA/cm² at a 0.56 V overpotential. With a SnO₂-based cathode catalyst, the HCOO^–-selective cell starts to operate at a 0.76 V overpotential and reaches a Faradaic efficiency of 82% and a partial current density of 113 mA/cm² at a 1.36 V overpotential. In contrast to previous studies, we found that the overpotential reduction from using the alkaline electrolyte is mostly contributed by a pH gradient near the cathode surface.

中文翻译：

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基于非贵金属催化剂的高性能电化学CO ₂还原电池

电化学减轻CO ₂的前景和挑战要求在催化剂和反应器水平上进行创新。在这项工作中，借助我们的高性能和富含地球的CO ₂电还原催化剂材料，我们开发了碱性微流电解槽，以实现高能效，选择性，快速和持久的CO ₂转化为CO和HCOO ^–。使用钴酞菁基阴极催化剂，CO选择性电池开始在0.26 V的超电势下运行，并在0.56 V的超电势下达到94％的法拉第效率和31 mA / cm ²的分电流密度。借助基于SnO ₂的阴极催化剂，HCOO ^–选择性电池开始在0.76 V的超电势下工作，并在1.36 V的超电势下达到82％的法拉第效率和113 mA / cm ²的部分电流密度。与以前的研究相反，我们发现使用碱性电解质引起的过电势降低主要是由阴极表面附近的pH梯度引起的。