Identifying Intermediates in Electrocatalytic Water Oxidation with a Manganese Corrole Complex

Xialiang Li, Xue Peng Zhang, Mian Guo, Bin Lv, Kai Guo, Xiaotong Jin, Wei Zhang, Yong Min Lee, Shunichi Fukuzumi, Wonwoo Nam, Rui Cao

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Water nucleophilic attack (WNA) on high-valent terminal Mn-oxo species is proposed for O-O bond formation in natural and artificial water oxidation. Herein, we report an electrocatalytic water oxidation reaction with MnIIItris(pentafluorophenyl)corrole (1) in propylene carbonate (PC). O2was generated at the MnV/IVpotential with hydroxide, but a more anodic potential was required to evolve O2with only water. With a synthetic MnV(O) complex of 1 , a second-order rate constant,k2(OH-), of 7.4 × 103M-1s-1was determined in the reaction of the MnV(O) complex of 1 with hydroxide, whereas its reaction with water occurred much more slowly with ak2(H2O) value of 4.4 × 10-3M-1s-1. This large reactivity difference of MnV(O) with hydroxide and water is consistent with different electrocatalytic behaviors of 1 with these two substrates. Significantly, during the electrolysis of 1 with water, a MnIV-peroxo species was identified with various spectroscopic methods, including UV-vis, electron paramagnetic resonance, and infrared spectroscopy. Isotope-labeling experiments confirmed that both O atoms of this peroxo species are derived from water, suggesting the involvement of the WNA mechanism in water oxidation by a Mn complex. Density functional theory calculations suggested that the nucleophilic attack of hydroxide on MnV(O) and also WNA to 1e--oxidized MnV(O) are feasibly involved in the catalytic cycles but that direct WNA to MnV(O) is not likely to be the main O-O bond formation pathway in the electrocatalytic water oxidation by 1

Original languageEnglish
Pages (from-to)14613-14621
Number of pages9
JournalJournal of the American Chemical Society
Volume143
Issue number36
DOIs
StatePublished - 15 Sep 2021

Fingerprint

Dive into the research topics of 'Identifying Intermediates in Electrocatalytic Water Oxidation with a Manganese Corrole Complex'. Together they form a unique fingerprint.

Cite this