Electrochemical reduction of carbon dioxide (CO₂) is an appealing approach toward tackling climate change associated with atmospheric CO₂ emissions. This approach uses CO₂ as the carbon feedstock to produce value‐added chemicals, resulting in a carbon‐neutral (or even carbon‐negative) process for chemical production. Many efforts have been devoted to the development of CO₂ electrolysis devices that can be operated at industrially relevant rates; however, limited progress has been made, especially for valuable C₂₊ products. Herein, a nanoporous copper CO₂ reduction catalyst is synthesized and integrated into a microfluidic CO₂ flow cell electrolyzer. The CO₂ electrolyzer exhibits a current density of 653 mA cm⁻² with a C₂₊ product selectivity of ≈62% at an applied potential of −0.67 V (vs reversible hydrogen electrode). The highly porous electrode structure facilitates rapid gas transport across the electrode–electrolyte interface at high current densities. Further investigations on electrolyte effects reveal that the surface pH value is substantially different from the pH of bulk electrolyte, especially for nonbuffering near‐neutral electrolytes when operating at high currents.

中文翻译：

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一种用于还原二氧化碳的高多孔铜电催化剂

电化学还原二氧化碳（CO ₂）是解决与大气CO ₂排放相关的气候变化的一种有吸引力的方法。这种方法使用CO ₂作为碳原料来生产增值化学品，从而实现了碳中性（甚至是碳负性）过程的化学生产。已经进行了许多努力来开发可以在工业上相关的速率下操作的CO ₂电解装置。但是，进展有限，特别是对于有价值的C ₂₊产品。在此，合成了纳米多孔铜CO ₂还原催化剂并将其整合到微流CO ₂流通池电解槽中。一氧化碳₂电解槽在-0.67 V施加的电势下（相对于可逆氢电极）显示出653 mA cm ^-2的电流密度和≈62％的C ₂₊产物选择性。高度多孔的电极结构可在高电流密度下促进气体快速穿过电极与电解质的界面传输。对电解质影响的进一步研究表明，表面pH值与散装电解质的pH值存在显着差异，尤其是在大电流条件下使用非缓冲性近中性电解质时。