A Fast Soluble Carbon-Free Molecular Water Oxidation Catalyst Based on Abundant Metals

Abstract

Traditional homogeneous water oxidation catalysts are plagued by instability under the reaction conditions. We report that the complex [Co4(H2O)2(PW9O34)2]10-, comprising a Co4O4 core stabilized by oxidatively resistant polytungstate ligands, is a hydrolytically and oxidatively stable homogeneous water oxidation catalyst that self-assembles in water from salts of earth-abundant elements (Co, W, and P). With [Ru(bpy)3]3+ (bpy is 2,2'-bipyridine) as the oxidant, we observe catalytic turnover frequencies for O2 production > or = 5 s(-1) at pH = 8. The rate's pH sensitivity reflects the pH dependence of the four-electron O2-H2O couple. Extensive spectroscopic, electrochemical, and inhibition studies firmly indicate that [Co4(H2O)2(PW9O34)2]10- is stable under catalytic turnover conditions: Neither hydrated cobalt ions nor cobalt hydroxide/oxide particles form in situ.

Cobalt‐Bridged Ionic Liquid Polymer on a Carbon Nanotube for Enhanced Oxygen Evolution Reaction Activity

“…A relative turnover frequency (TOF) of 0.29 s −1 is obtained at overpotential 400 mV (details in Supporting Information). This is comparable with some homogeneous catalysts 16. Figure S10 shows a decreasing capacitance with increasing IL/Co ratio.…”

Charge photo-accumulation and photocatalytic hydrogen evolution under visible light at an iridium(iii)-photosensitized polyoxotungstate

“…[1][2][3][4] In the past decades, molecular approaches have mostly focused on one hand on the design of photosensitive systems displaying long-lived photo-induced charge separation states to permit further electron transfers 5-10 and, on the other hand, on catalysts able to use these photogenerated charges for achieving either oxygen [11][12][13][14][15][16][17][18] or hydrogen evolution. [19][20][21][22][23][24] As these two reactions are multi-electronic processes while photosensitizers deliver electrons and holes sequentially, the charges need to be directed to a charge accumulation site.…”

Binuclear [(cod)(Cl)Ir(bpi)Ir(cod)]+ for Catalytic Water Oxidation

“…18 In case of [1]PF 6 no significant catalyst deactivation was observed after 2 hours and at least 1000 turnovers. …”