Nafion is a widely used fluoropolymer that is often mixed with electrocatalysts to facilitate proton transport. In contrast to these Nafion-catalyst composites, this work studies electrodes covered by Nafion overlayers for the CO₂ reduction reaction. By varying the thickness, substrates, and voltage, we perform a detailed study of the effect of Nafion overlayers on metal and carbon mesh electrodes for CO₂ reduction. Depending on the thickness of the Nafion membrane, CO₂ reduction occurs at either the polymer–electrolyte interface or electrode–polymer interface. A Nafion overlayer of 15 μm on a Cu electrode enables an extraordinarily high yield of CH₄ production (88% Faradaic efficiency) at a low overpotential (540 mV) via the stabilization of metal-bound CO intermediates. To the best of our knowledge, this yield is the highest for electrocatalytic CO₂ reduction to CH₄ production at room temperature reported.

中文翻译：

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在质子可渗透膜的存在下，以极高的法拉第效率将电化学CO2还原为甲烷

Nafion是一种广泛使用的含氟聚合物，通常与电催化剂混合以促进质子运输。与这些Nafion催化剂复合材料相比，这项工作研究了Nafion覆盖层覆盖的电极用于CO ₂还原反应。通过改变厚度，基板和电压，我们对Nafion覆盖层对金属和碳网电极上的CO ₂还原效果进行了详细研究。根据Nafion膜的厚度，在聚合物-电解质界面或电极-聚合物界面处都会发生CO ₂还原。铜电极上15μm的Nafion覆盖层可在低过电势（540 mV）的情况下实现CH ₄生产的极高产量（法拉第效率为88％）通过稳定与金属结合的一氧化碳中间体。据我们所知，在室温下，该收率是电催化将CO ₂还原为CH ₄的最高产量。