The deployment of gas diffusion electrodes (GDEs) for the electrochemical CO₂ reduction reaction (CO2RR) has enabled current densities an order of magnitude greater than those of aqueous H cells. The gains in production, however, have come with stability challenges due to rapid flooding of GDEs, which frustrate both laboratory experiments and scale-up prospects. Here, we investigate the role of carbon gas diffusion layers (GDLs) in the advent of flooding during CO2RR, finding that applied potential plays a central role in the observed instabilities. Electrochemical characterization of carbon GDLs with and without catalysts suggests that the high overpotential required during electrochemical CO2RR initiates hydrogen evolution on the carbon GDL support. These potentials impact the wetting characteristics of the hydrophobic GDL, resulting in flooding that is independent of CO2RR. Findings from this work can be extended to any electrochemical reduction reaction using carbon-based GDEs (CORR or N₂RR) with cathodic overpotentials of less than −0.65 V versus a reversible hydrogen electrode.

中文翻译：

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碳基气体扩散层在气体扩散电极池中减少CO ₂电化学作用中的驱替作用

部署用于化学CO ₂的气体扩散电极（GDE）还原反应（CO2RR）使电流密度比水性H电池高一个数量级。然而，由于GDE的快速泛滥，产量的增加带来了稳定性方面的挑战，这挫败了实验室实验和扩大规模的前景。在这里，我们研究了二氧化碳扩散层（GDLs）在CO2RR期间洪水泛滥中的作用，发现所施加的电势在观察到的不稳定性中起着核心作用。含或不含催化剂的碳GDL的电化学表征表明，电化学CO2RR期间所需的高超电势引发了碳GDL载体上的氢释放。这些电势会影响疏水性GDL的润湿特性，从而导致泛滥而与CO2RR无关。相对于可逆氢电极，其阴极超电势小于-0.65 V（₂ RR）。