WVI–OH functionality on polyoxometalates for water reduction to molecular hydrogen†
Abstract
Grafting a WVI–(OH)2 functionality on the surface of polyoxometalates (POMs) makes the concerned POM compounds, Na6[{CoII(H2O)3}2{WVI(OH)2}2{(BiIIIWVI9O33)2}]·8H2O (1) and Na4(Himi)2[{MnII(H2O)3}2{WVI(OH)2}2{(BiIIIWVI9O33)2}]·28H2O (2) prominent heterogeneous electrocatalysts for water reduction to molecular hydrogen. We have identified that the WVI–(OH)2 functionality acts as the active site for electrocatalytic hydrogen evolution reaction (HER). The chances of in situ generation and participation of secondary species (metal nanoparticles etc.) in the present electrocatalysis have been eliminated by performing controlled experiments. The electrocatalysts 1 and 2 are stable enough towards HER up to 1000 cycles of cyclic voltammetric measurement and 10 hours chronoamperometry. The relevant turnover frequencies of 1 and 2 are 0.593 s−1 and 0.634 s−1 respectively exhibiting high efficiency towards electrocatalytic HER. This work has potential to generalize that POMs having M–OH functionality attached on its cluster surface would function as catalysts for HER.
- This article is part of the themed collection: FOCUS: Metal and Metal-Containing Clusters