Sulfur Coordination Effects on the Stability and Activity of a Ruthenium-Based Water Oxidation Catalyst

Jing Yang; Junxue An; Lianpeng Tong; Baihua Long; Ting Fan; Lele Duan

doi:10.1021/acs.inorgchem.8b03199

Sulfur Coordination Effects on the Stability and Activity of a Ruthenium-Based Water Oxidation Catalyst

Inorg Chem. 2019 Mar 4;58(5):3137-3144. doi: 10.1021/acs.inorgchem.8b03199. Epub 2019 Feb 20.

Authors

Jing Yang¹, Junxue An², Lianpeng Tong³, Baihua Long¹, Ting Fan⁴, Lele Duan¹

Affiliations

¹ Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology (SUSTech) , Shenzhen , 518055 , P. R. China.
² Department of Pharmacy , Uppsala University , Uppsala , SE-75123 , Sweden.
³ Department of Chemistry and Chemical Engineering , Guangzhou University , Guangzhou , 510006 , P. R. China.
⁴ School of Chemistry and Chemical Engineering , South China University of Technology , Guangzhou 510641 , P. R. China.

PMID: 30785733
DOI: 10.1021/acs.inorgchem.8b03199

Abstract

Water oxidation is regarded as the bottleneck of the water splitting and the development of water oxidation catalysts is of importance in the view of reducing reaction barriers and promoting water oxidation efficiency. Recently, the Sun group has disclosed a family of highly active water oxidation catalysts, [Ru(bda)(L)₂] (bda^2- = 2,2'-bipyridine-6,6'-dicarboxylate; L = N-containing ligands). Herein, we replaced the bda^2- ligand with a 2,2'-bipyridine-6,6'-dicarbothioate (bct^2-) ligand and prepared a mononuclear ruthenium complex [Ru(bct)(pic)₂] (Ru-bct, pic = 4-picoline). Less equatorial ligand distortion is observed for Ru^II-bct which displays improved stability than Ru^II-bda. The Ru-bct complex undergoes chemical-structural evolution during electrochemical and chemical oxidation, generating Ru-bda as the intrinsic active species to afford water oxidation. This study provides an example to understand structure-stability-reactivity relationship of molecular water oxidation catalysts.