Zhao Yonggui, Adiyeri Saseendran Devi Prasad, Huang Chong, Triana Carlos A, Marks Walker R, Chen Hang, Zhao Han, Patzke Greta R
Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
Chem Rev. 2023 May 10;123(9):6257-6358. doi: 10.1021/acs.chemrev.2c00515. Epub 2023 Mar 21.
The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are core steps of various energy conversion and storage systems. However, their sluggish reaction kinetics, i.e., the demanding multielectron transfer processes, still render OER/ORR catalysts less efficient for practical applications. Moreover, the complexity of the catalyst-electrolyte interface makes a comprehensive understanding of the intrinsic OER/ORR mechanisms challenging. Fortunately, recent advances of / characterization techniques have facilitated the kinetic monitoring of catalysts under reaction conditions. Here we provide selected highlights of recent / mechanistic studies of OER/ORR catalysts with the main emphasis placed on heterogeneous systems (primarily discussing first-row transition metals which operate under basic conditions), followed by a brief outlook on molecular catalysts. Key sections in this review are focused on determination of the true active species, identification of the active sites, and monitoring of the reactive intermediates. For in-depth insights into the above factors, a short overview of the metrics for accurate characterizations of OER/ORR catalysts is provided. A combination of the obtained time-resolved reaction information and reliable activity data will then guide the rational design of new catalysts. Strategies such as optimizing the restructuring process as well as overcoming the adsorption-energy scaling relations will be discussed. Finally, pending current challenges and prospects toward the understanding and development of efficient heterogeneous catalysts and selected homogeneous catalysts are presented.
析氧反应（OER）和氧还原反应（ORR）是各种能量转换和存储系统的核心步骤。然而，它们缓慢的反应动力学，即苛刻的多电子转移过程，仍然使得OER/ORR催化剂在实际应用中的效率较低。此外，催化剂-电解质界面的复杂性使得全面理解OER/ORR的内在机制具有挑战性。幸运的是，表征技术的最新进展促进了对反应条件下催化剂的动力学监测。在此，我们提供了OER/ORR催化剂近期机理研究的精选亮点，主要侧重于多相体系（主要讨论在碱性条件下运行的第一行过渡金属），随后简要展望分子催化剂。本综述的关键部分集中在确定真正的活性物种、识别活性位点以及监测反应中间体。为了深入了解上述因素，我们提供了用于准确表征OER/ORR催化剂的指标的简短概述。所获得的时间分辨反应信息和可靠的活性数据相结合，将指导新型催化剂的合理设计。我们将讨论诸如优化重构过程以及克服吸附能标度关系等策略。最后，介绍了在理解和开发高效多相催化剂和选定的均相催化剂方面当前面临的挑战和前景。
