Elucidation of Factors That Govern the 2e/2H+ vs 4e/4H+ Selectivity of Water Oxidation by a Cobalt Corrole

Cite this: J. Am. Chem. Soc. 2020, 142, 50, 21040–21049
Publication Date (Web):December 1, 2020
Copyright © 2020 American Chemical Society
Article Views
Read OnlinePDF (4 MB)
Supporting Info (1)»


Considering the importance of water splitting as the best solution for clean and renewable energy, the worldwide efforts for development of increasingly active molecular water oxidation catalysts must be accompanied by studies that focus on elucidating the mode of actions and catalytic pathways. One crucial challenge remains the elucidation of the factors that determine the selectivity of water oxidation by the desired 4e/4H+ pathway that leads to O2 rather than by 2e/2H+ to H2O2. We now show that water oxidation with the cobalt–corrole CoBr8 as electrocatalyst affords H2O2 as the main product in homogeneous solutions, while heterogeneous water oxidation by the same catalyst leads exclusively to oxygen. Experimental and computation-based investigations of the species formed during the process uncover the formation of a Co(III)–superoxide intermediate and its preceding high-valent Co–oxyl complex. The competition between the base-catalyzed hydrolysis of Co(III)–hydroperoxide [Co(III)–OOH] to release H2O2 and the electrochemical oxidation of the same to release O2 via [Co(III)–O2] is identified as the key step determining the selectivity of water oxidation.

Supporting Information

Jump To

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/jacs.0c08654.

  • Details of the experimental procedure, materials, additional electrochemical and spectroscopic data, and coordinates of the optimized geometries (PDF)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Cited By

This article is cited by 5 publications.

  1. Kan Zhang, Yuan Lu, Qianqian Zou, Jie Jin, Yoonjun Cho, Yuqing Wang, Yan Zhang, Jong Hyeok Park. Tuning Selectivity of Photoelectrochemical Water Oxidation via Facet-Engineered Interfacial Energetics. ACS Energy Letters 2021, 6 (11) , 4071-4078. https://doi.org/10.1021/acsenergylett.1c01831
  2. Guo Chen, Ze-Wen Chen, Yuan-Mei Wang, Piao He, Chao Liu, Hai-Xia Tong, Xiao-Yi Yi. Efficient Electrochemical Water Oxidation Mediated by Pyridylpyrrole-Carboxylate Ruthenium Complexes. Inorganic Chemistry 2021, 60 (20) , 15627-15634. https://doi.org/10.1021/acs.inorgchem.1c02251
  3. Qi-Fa Chen, Yu-Hua Guo, Yi-Han Yu, Ming-Tian Zhang. Bioinspired molecular clusters for water oxidation. Coordination Chemistry Reviews 2021, 448 , 214164. https://doi.org/10.1016/j.ccr.2021.214164
  4. Yuliang Li, Ni Wang, Haitao Lei, Xialiang Li, Haoquan Zheng, Hongyan Wang, Wei Zhang, Rui Cao. Bioinspired N4-metallomacrocycles for electrocatalytic oxygen reduction reaction. Coordination Chemistry Reviews 2021, 442 , 213996. https://doi.org/10.1016/j.ccr.2021.213996
  5. Xiaotong Jin, Xialiang Li, Haitao Lei, Kai Guo, Bin Lv, Hongbo Guo, Dandan Chen, Wei Zhang, Rui Cao. Comparing electrocatalytic hydrogen and oxygen evolution activities of first-row transition metal complexes with similar coordination environments. Journal of Energy Chemistry 2021, 115 https://doi.org/10.1016/j.jechem.2021.08.068