Catalytic CO_x (CO and CO₂) hydrogenation to valued chemicals is one of the promising approaches to address challenges in energy, environment, and climate change. H₂O is an inevitable side product in these reactions, where its existence and effect are often ignored. In fact, H₂O significantly influences the catalytic active centers, reaction mechanism, and catalytic performance, preventing us from a definitive and deep understanding on the structure-performance relationship of the authentic catalysts. It is necessary, although challenging, to clarify its effect and provide practical strategies to tune the concentration and distribution of H₂O to optimize its influence. In this review, we focus on how H₂O in CO_x hydrogenation induces the structural evolution of catalysts and assists in the catalytic processes, as well as efforts to understand the underlying mechanism. We summarize and discuss some representative tuning strategies for realizing the rapid removal or local enrichment of H₂O around the catalysts, along with brief techno-economic analysis and life cycle assessment. These fundamental understandings and strategies are further extended to the reactions of CO and CO₂ reduction under an external field (light, electricity, and plasma). We also present suggestions and prospects for deciphering and controlling the effect of H₂O in practical applications.

中文翻译：

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了解和调整 H2O 对催化 CO 和 CO2 加氢的影响


催化 CO_x（CO 和 CO₂）加氢制有价值的化学品是应对能源、环境和气候变化挑战的有前途的方法之一。H₂O 是这些反应中不可避免的副产物，它的存在和影响经常被忽视。事实上，H₂O 显着影响催化活性中心、反应机理和催化性能，使我们无法对真实催化剂的结构-性能关系进行明确和深入的理解。尽管具有挑战性，但有必要阐明其影响并提供实用策略来调整 H₂O 的浓度和分布以优化其影响。在这篇综述中，我们重点介绍了 CO_x 加氢反应中的 H₂O 如何诱导催化剂的结构演变并协助催化过程，以及了解潜在机制的努力。我们总结并讨论了一些具有代表性的调谐策略，以实现催化剂周围 H₂O 的快速去除或局部富集，并进行了简短的技术经济分析和生命周期评估。这些基本理解和策略进一步扩展到外部场（光、电和等离子体）下 CO 和 CO₂ 还原的反应。我们还为在实际应用中破译和控制 H₂O 的影响提出了建议和展望。