A molecular catalyst for water oxidation that binds to metal oxide surfaces

Abstract

Molecular catalysts are known for their high activity and tunability, but their solubility and limited stability often restrict their use in practical applications. Here we describe how a molecular iridium catalyst for water oxidation directly and robustly binds to oxide surfaces without the need for any external stimulus or additional linking groups. On conductive electrode surfaces, this heterogenized molecular catalyst oxidizes water with low overpotential, high turnover frequency and minimal degradation. Spectroscopic and electrochemical studies show that it does not decompose into iridium oxide, thus preserving its molecular identity, and that it is capable of sustaining high activity towards water oxidation with stability comparable to state-of-the-art bulk metal oxide catalysts.

Electrochemical Water Oxidation Catalyzed by an In Situ Generated α‐Co(OH)2 Film on Zeolite‐Y Surface

“…[1][2][3][4][5][6][7] Among these, ah eterogeneous electrocatalyst is of particulari nterest because it offers extra stability, and the relevant electrocatalytic method can directly be implemented into devices. [8][9][10][11][12] The known heterogeneous WOCs are metal oxides, including spinel oxides, monomeric, dimeric,a nd tetrameric molecular complexes, polyoxometalates (POMs) and POM-supported metal complexes,v arious nano-materials, electrodeposited metals from aqueous solutionso fm etal salts, amorphous metal-oxide thin-films, and metal-organic framework (MOF)-containing compounds. [2,[13][14][15][16][17] Although this large body of molecular transition-metal catalysts and active metal-oxide materials has been developed for water oxidation, substantial challenges remain for the ultimate goal of an efficient, inexpensive, and robust electrocatalyst.…”

Water Oxidation by Ruthenium Complexes Incorporating Multifunctional Bipyridyl Diphosphonate Ligands

“…Owing to demands imposed by unprecedented levels of worldwide energy consumption and changes to the global climate, this goal has become more than a scientific curiosity. Reaching this milestone requires the development of water oxidation catalysts capable of promoting this half reaction efficiently, at high rates, and for long periods of time.Known molecular catalysts for water oxidation include both multinuclear [2] and mononuclear complexes; [3] single-site catalysts are a particular case of each of these types. [4] Molecular systems are attractive because of the potential to tune their properties by varying the ligand and/or metal.…”

The Principle of Photoelectrochemical Water Splitting

“…Molecular catalysts have advantages of high activity and tunability [48]. The first homogeneous catalyst for PEC is a rutheniumbased catalyst.…”