The oxygen reduction reaction (ORR) is a key component for many clean energy technologies and other industrial processes. However, the low selectivity and the sluggish reaction kinetics of ORR catalysts have hampered the energy conversion efficiency and real application of these new technologies mentioned before. Recently, tremendous efforts have been made in mechanism understanding, electrocatalyst development and system design. Here, a comprehensive and critical review is provided to present the recent advances in the field of the electrocatalytic ORR. The two-electron and four-electron transfer catalytic mechanisms and key evaluation parameters of the ORR are discussed first. Then, the up-to-date synthetic strategies and in situ characterization techniques for ORR electrocatalysts are systematically summarized. Lastly, a brief overview of various renewable energy conversion devices and systems involving the ORR, including fuel cells, metal–air batteries, production of hydrogen peroxide and other chemical synthesis processes, along with some challenges and opportunities, is presented.

中文翻译：

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选择性氧还原反应：机理理解、催化剂设计和实际应用


氧还原反应 (ORR) 是许多清洁能源技术和其他工业过程的关键组成部分。然而，ORR催化剂的低选择性和缓慢的反应动力学阻碍了上述新技术的能量转换效率和实际应用。最近，人们在机理理解、电催化剂开发和系统设计方面做出了巨大努力。在此，我们对电催化 ORR 领域的最新进展进行了全面而批判性的回顾。首先讨论了ORR的二电子和四电子转移催化机制和关键评估参数。然后系统总结了ORR电催化剂的最新合成策略和原位表征技术。最后，简要概述了涉及 ORR 的各种可再生能源转换装置和系统，包括燃料电池、金属空气电池、过氧化氢生产和其他化学合成过程，以及一些挑战和机遇。