The conversion of CO₂ to CO is demonstrated in an electrolyzer flow cell containing a bipolar membrane at current densities of 200 mA/cm² with a Faradaic efficiency of 50%. Electrolysis was carried out by delivering gaseous CO₂ at the cathode with a silver catalyst integrated in a carbon-based gas diffusion layer. Nonprecious nickel foam in a strongly alkaline electrolyte (1 M NaOH) was used to mediate the anode reaction. While a configuration where the anode and cathode were separated by only a bipolar membrane was found to be unfavorable for robust CO₂ reduction, a modified configuration with a solid-supported aqueous layer inserted between the silver-based catalyst layer and the bipolar membrane enhanced the cathode selectivity for CO₂ reduction to CO. We report higher current densities (200 mA/cm²) than previously reported for gas-phase CO₂ to CO electrolysis and demonstrate the dependence of long-term stability on adequate hydration of the CO₂ inlet stream.

中文翻译：

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带有双极膜的流通池中气态CO ₂到CO的电解

在包含双极膜的电解池流通池中，以200 mA / cm ^2的电流密度和法拉第效率为50％证明了CO ₂向CO的转化。电解是通过在阴极处输送气态CO ₂以及集成在碳基气体扩散层中的银催化剂来进行的。使用强碱性电解液（1 M NaOH）中的非贵金属泡沫镍来介导阳极反应。虽然发现阳极和阴极仅被双极性膜隔开的配置不利于坚固的CO ₂还原后，在银基催化剂层和双极性膜之间插入了固体支撑的水层，从而获得了改进的构型，从而提高了将CO ₂还原为CO的阴极选择性。我们报道了更高的电流密度（200 mA / cm ²）用于气相CO ₂到CO的电解，并证明了长期稳定性对CO ₂入口物流充分水合的依赖性。