Water Oxidation by a Neoteric Dinuclear Mn(II) Electrocatalyst in Aqueous Medium

Abstract

The employment of manganese complexes towards electrocatalytic water oxidation has gained immense interest among the scientific communities. In this present study, the reaction of Mn(CH 3 COO) 2 •4H 2 O with the novel ligand (2-([2,2':6',2"-terpyridin]-4'-yl)quinoline-8-ol) (8hq-tpy) affords a dinuclear manganese complex, [Mn II (8hq-tpy)(H 2 O)] 2 (PF 6 ) 2 (Mn 1). Various spectroscopic techniques have been implemented for characterization purposes, and Mn 1 is employed as electrocatalysts towards water oxidation catalysis in the aqueous medium. Electrocatalytic responses in the aqueous medium at pH 6.0 lead to the electrodeposition of heterogeneous species (MnO X ) which enables the oxidation event at an applied potential of 1.24 V vs. NHE with O 2 liberation of 50.2 μmol/L. The XPS analysis performed after executing bulk electrolysis, provide evidence for the generation of Mn IV = O as the active species formed by the catalyst precursor complex Mn 1, contributing to O 2 evolution during the electrocatalytic water oxidation process.