Cu-based materials are promising electrocatalysts for CO₂/CO conversion as they allow synthesis of useful multicarbon products. However, a greater understanding of how catalyst preparation impacts product selectivity is needed. Now, Hee-Tae Jung, Christopher Hahn, Joel Ager and colleagues in South Korea and the USA show that a key feature of a Cu catalyst’s ability to form ethylene is the presence of an abundance of ‘reservoir’ sites that bind CO but do not convert it.

Using a gas diffusion electrode cell equipped with a Cu catalyst, the researchers explore the dynamic response of the system when the feed is abruptly switched between an inert gas (Ar) and CO. They observe that CO reduction begins immediately on switching from Ar to CO, but that when going from CO to Ar, there is a delay of several seconds. Amongst other variables, the length of this delay is dependent on the Cu catalyst preparation, with the longest delay occurring when using a catalyst derived from an oxide material.

铜基材料是有前景的CO ₂ /CO转化电催化剂，因为它们可以合成有用的多碳产品。然而，需要更好地了解催化剂制备如何影响产物选择性。现在，Hee-Tae Jung、Christopher Hahn、Joel Ager 及其韩国和美国的同事表明，Cu 催化剂形成乙烯能力的一个关键特征是存在大量的“储存库”位点，这些位点可以结合 CO，但不结合 CO。转换它。

研究人员使用配备 Cu 催化剂的气体扩散电极电池，探索了当进料在惰性气体 (Ar) 和 CO 之间突然切换时系统的动态响应。他们观察到，从 Ar 切换到 CO 后，CO 立即开始还原，但是从 CO 到 Ar 时，有几秒钟的延迟。除其他变量外，该延迟的长度取决于铜催化剂的制备，当使用源自氧化物材料的催化剂时出现最长的延迟。