Copper is well known in fundamental electrocatalysis research due to its ability to selectively reduce CO₂ to C₂ products. Recent, more applied studies have revealed that electrolyzers based on Cu electrocatalysts can reach current densities of up to hundreds of mA cm⁻². This opens up the opportunity for industrial application of Cu-based electrocatalysts. However, the stability of copper must first be assessed. In this communication we investigate the electrochemical corrosion behavior of copper in a broad pH window relevant to CO₂ reduction applications. Using an electrochemical on-line inductively coupled plasma mass spectrometer (ICP-MS), we quantify Cu dissolution during anodic oxidation and during the reduction of electrochemically formed oxide species. We show that electrochemical oxidation of Cu leads to high dissolution in neutral and highly alkaline environments, while an intermediate pH of around 9–10 leads to minimal dissolution. The obtained results are discussed in relation to the CO₂ reduction reaction to set a benchmark for stable Cu-based electrocatalysts.

铜由于能够选择性地将CO ₂还原为C ₂产物而在基础电催化研究中众所周知。最近，更多的应用研究表明，基于铜电催化剂的电解槽可以达到高达数百mA cm ^-2的电流密度。这为铜基电催化剂的工业应用开辟了机会。但是，必须首先评估铜的稳定性。在此交流中，我们研究了在与CO ₂有关的宽pH窗口中铜的电化学腐蚀行为减少应用。使用电化学在线电感耦合等离子体质谱仪（ICP-MS），我们可以量化在阳极氧化过程中以及在电化学形成的氧化物物种还原过程中Cu的溶解度。我们表明，铜的电化学氧化导致在中性和高度碱性环境中的高度溶解，而中间pH值约为9-10则导致最小的溶解。讨论了与CO ₂还原反应有关的所得结果，以为稳定的铜基电催化剂设定基准。