The deployment of electrolyzers that convert CO₂ into chemicals and fuels requires appropriate integration with upstream carbon capture processes. To this end, the electrolytic conversion of aqueous (bi)carbonate offers the opportunity to avoid the energy-intensive steps currently used to extract pressurized CO₂ from carbon capture solutions. We demonstrate here that an optimized silver gas diffusion electrode (GDE) architecture enables conversion of model carbon capture solutions (i.e., 3 M KHCO₃) into CO at partial current densities (J_CO) greater than 100 mA cm^–2 with CO₂ utilization rates of ∼70%. These results exceed the performance of any previously reported liquid-fed CO₂ electrolyzers and rival gas-fed devices. We were able to hit these metrics through the systematic design of gas diffusion layer (GDL) components (e.g., polytetrafluoroethylene) and catalyst layer constituents (i.e., Nafion, silver) on CO production. A key finding of this work is that hydrophobic GDE components (which are common to gas-fed CO₂RR electrolyzers) decrease in situ CO₂ generation and thus the formation of the final CO product. These findings show a clear path toward industrially relevant reactors that couple electrolytic CO₂ conversion with carbon capture.

中文翻译：

---

用于将碳酸氢盐转化为CO的电极

部署将CO ₂转化为化学物质和燃料的电解槽需要与上游的碳捕获过程进行适当整合。为此，碳酸（碳酸氢盐）水溶液的电解转化提供了避免目前用于从碳捕获溶液中提取加压的CO ₂的高能耗步骤的机会。我们在此证明，一种优化的银气扩散电极（GDE）架构能够在CO ₂大于100 mA cm ^–2的部分电流密度（J _CO）下将模型碳捕获溶液（即3 M KHCO ₃）转化为CO。利用率约70％。这些结果超过了以前报道的任何液态CO ₂电解槽和竞争对手的气态设备的性能。通过对CO生产中气体扩散层（GDL）组件（例如，聚四氟乙烯）和催化剂层成分（即，Nafion，银）的系统设计，我们能够达到这些指标。这项工作的关键发现是疏水性GDE组分（气态CO ₂ RR电解器常见）减少了原位CO _2的生成，从而减少了最终CO产品的形成。这些发现表明，将电解的CO ₂转化与碳捕获结合起来的工业相关反应器是一条清晰的道路。