Revealing and redirecting the dynamic evolution of active species in efficient electrochemical CO2 reduction (ECR) catalysts is challenging. By observing the chemical and morphological evolution in highly efficient ECR catalysts at the nanoscale via operando soft X-ray microscopy, we identified the dynamic transformation of cationic Cu species during operation. The surface Cu2+ phases, observed during a dynamic phase transformation of Cu(OH)2, additionally boost C–C coupling activity beyond the capability of metallic Cu phases. We suggest that copper(II)-carbonate-hydroxide species could dynamically persist under a cathodic environment. By observing the Cu+ phase during the phase transformation and the formation of surface Cu2+ species, we were able to electrochemically redirect low-active catalysts into high-active catalysts for C–C coupling. Density functional theory calculations also support that Cu2+ species could contribute to C–C coupling activity enhancement via ∗CO adsorption energy modulation.

中文翻译：

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CO2 电催化的时空活性相析出


揭示和重定向高效电化学 CO2 还原 （ECR） 催化剂中活性物质的动态演变具有挑战性。通过原位软 X 射线显微镜在纳米尺度上观察高效 ECR 催化剂的化学和形态演变，我们确定了阳离子 Cu 物种在运行过程中的动态转变。在 Cu（OH）2 的动态相变过程中观察到的表面 Cu2+ 相还提高了 C-C 耦合活性，超出了金属 Cu 相的能力。我们认为铜 （II） -碳酸盐-氢氧化物物质可以在阴极环境中动态地持续存在。通过观察相变过程中的 Cu+ 相和表面 Cu2+ 物种的形成，我们能够电化学地将低活性催化剂重定向到高活性催化剂中，用于 C-C 耦合。密度泛函理论计算也支持 Cu2+ 物质可以通过 ∗CO 吸附能量调制促进 C-C 耦合活性增强。