Electrocatalytic CO2 reduction (ECR) is a promising approach for achieving carbon neutrality due to its ability to convert CO2 to valuable chemicals. Recent advances have significantly enhanced the ECR performance of various catalysts by tuning their oxidation states, particularly for Cu-based catalysts that can reduce CO2 to multiple products. However, the oxidation state of copper (OSCu), especially Cu+, changes during the reaction process, posing significant challenges for both catalyst characterization and performance. In this review, the current understanding of the effect of oxidation states on product selectivity was first discussed. A comprehensive overview of in situ/operando characterization techniques, used to monitor the dynamic evolution of oxidation states during ECR, was then provided. Various strategies for stabilizing oxidation states through modification of catalysts and manipulation of external conditions were discussed. This review aimed to deepen the understanding of oxidation states in ECR and enlighten the development of more efficient electrocatalysts.

中文翻译：

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了解用于电催化 CO2 还原的 Cu 基催化剂的氧化态


电催化 CO2 还原 （ECR） 是实现碳中和的一种很有前途的方法，因为它能够将 CO2 转化为有价值的化学品。最近的进展通过调整各种催化剂的氧化态，显著提高了其 ECR 性能，特别是对于可以将 CO2 还原为多种产物的铜基催化剂。然而，铜的氧化态 （OSCu），尤其是 Cu+，在反应过程中会发生变化，这对催化剂的表征和性能都构成了重大挑战。在这篇综述中，首先讨论了目前对氧化态对产品选择性影响的理解。然后全面概述了用于监测 ECR 期间氧化态动态演变的原位/原位表征技术。讨论了通过催化剂改性和操纵外部条件来稳定氧化态的各种策略。本文旨在加深对 ECR 中氧化态的理解，并为开发更高效的电催化剂提供启发。