Direct electrochemical conversion of CO₂ capture solutions (instead of gaseous CO₂) to valuable chemicals can circumvent the energy-intensive CO₂ regeneration and pressurization steps, but the performance of such processes is limited by the sluggish release of CO₂ and the use of energy-consuming bipolar membranes (BPMs). Herein, we discovered that an ammonium bicarbonate (NH₄HCO₃)-fed electrolyzer outperforms the state-of-the-art KHCO₃ electrolyzers largely because of its favorable thermal decomposition property, which allows for a 3-fold increase in the in situ CO₂ concentration, a maximum 23% increase in formate faradaic efficiency, and a 35% reduction in cell voltage by substituting BPM with an anion exchange membrane (AEM). We then demonstrated an integrated process by combining NH₄HCO₃ electrolysis with CO₂ capture by on-site generated ammonia from the electroreduction of nitrate, which features a remarkable 99.8% utilization of of CO₂ capturing agent. Such a multipurpose process offers a sustainable route for the simultaneous removal of N wastes and streamlined CO₂ capturing and upgrading.

中文翻译：

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氨介导的 CO2 捕获和直接电还原生成甲酸盐

_{将 CO 2}捕获溶液（而不是气态 CO ₂ ）直接电化学转化为有价值的化学品可以绕过能源密集型 CO ₂再生和加压步骤，但此类过程的性能受到 CO ₂缓慢释放和使用耗能双极膜 (BPM)。在此，我们发现以碳酸氢铵 (NH ₄ HCO ₃ ) 为原料的电解槽的性能优于最先进的 KHCO _{3电解槽，这主要是因为它具有良好的热分解性能，可以使原位电解槽的}原位增加 3 倍二氧化碳_{_}通过用阴离子交换膜 (AEM) 替代 BPM，甲酸盐法拉第效率最多可提高 23%，电池电压可降低 35%。然后，我们展示了一个集成工艺，将 NH ₄ HCO ₃电解与硝酸盐电还原现场产生的氨捕获 CO _{2相结合，其特点是 CO 2}捕获剂的利用率高达 99.8% 。这种多用途工艺为同时去除 N 废物和简化 CO ₂捕获和升级提供了可持续途径。