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Tracking the Role of Defect Types in Co3O4 Structural Evolution and Active Motifs during Oxygen Evolution Reaction
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2023-01-18 , DOI: 10.1021/jacs.2c10515
Rongrong Zhang 1, 2, 3 , Lun Pan 1, 4, 5 , Beibei Guo 1 , Zhen-Feng Huang 1, 4, 5 , Zhongxin Chen 3 , Li Wang 1, 4, 5 , Xiangwen Zhang 1, 4, 5 , Zhiying Guo 6 , Wei Xu 6 , Kian Ping Loh 2, 3 , Ji-Jun Zou 1, 4, 5
Affiliation  

Dynamic reconstruction of catalyst active sites is particularly important for metal oxide-catalyzed oxygen evolution reaction (OER). However, the mechanism of how vacancy-induced reconstruction aids OER remains ambiguous. Here, we use Co3O4 with Co or O vacancies to uncover the effects of different defects in the reconstruction process and the active motifs relevant to alkaline OER. Combining in situ characterization and theoretical calculations, we found that cobalt oxides are converted to an amorphous [Co(OH)6] intermediate state, and then the mismatched rates of *OH adsorption and deprotonation lead to irreversible catalyst reconstruction. The stronger *OH adsorption but weaker deprotonation induced by O defects provides the driving force for reconstruction, while Co defects favor dehydrogenation and reduce the reconstruction rate. Importantly, both O and Co defects trigger highly OER-active bridge Co sites in reconstructed catalysts, of which Co defects induce a short Co–Co distance (3.38 Å) under compressive lattice stress and show the best OER activity (η10 of 262 mV), superior to reconstructed oxygen-defected Co3O4-VO10 of 300 mV) and defect-free Co3O410 of 320 mV). This work highlights that engineering defect-dependent reconstruction may provide a rational route for electrocatalyst design in energy-related applications.

中文翻译:

跟踪缺陷类型在 Co3O4 结构演化和析氧反应中活性基序中的作用

催化剂活性位点的动态重建对于金属氧化物催化的析氧反应(OER)尤为重要。然而,空缺引起的重建如何帮助 OER 的机制仍然不明确。在这里,我们使用具有 Co 或 O 空位的 Co 3 O 4来揭示重建过程中不同缺陷的影响以及与碱性 OER 相关的活性基序。结合原位表征和理论计算,我们发现钴氧化物转化为无定形 [Co(OH) 6] 中间状态,然后 *OH 吸附和去质子化的不匹配速率导致不可逆的催化剂重建。O缺陷引起的*OH吸附更强但去质子化较弱,为重建提供了驱动力,而Co缺陷有利于脱氢并降低重建速率。重要的是,O 和 Co 缺陷都会触发重构催化剂中高 OER 活性的桥 Co 位点,其中 Co 缺陷在压缩晶格应力下会导致短的 Co-Co 距离 (3.38 Å),并显示出最佳的 OER 活性(η 10为 262 mV ),优于重建的缺氧 Co 3 O 4 -V O(η 10为 300 mV)和无缺陷的 Co 3 O 410为 320 mV)。这项工作强调,工程缺陷相关的重建可能为能源相关应用中的电催化剂设计提供一条合理的途径。
更新日期:2023-01-18
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