Development of water oxidation catalysts to replace costly noble metals in commercial electrolyzers and solar fuel cells has been an unmet need preventing global development of hydrogen fuel technologies. In this context researchers at Rutgers University have developed novel transition metal oxide spinel catalysts having a M4O4 core for electrolysis of water molecules and hydrocarbons. In particular they have found that materials in one of the two crystalline forms of LiCo2O4 namely low-temperature cubic spinel Li1+yCo2O4 (y ≤ 1) are highly active in catalyzing water oxidation. These materials were obtained by evaporation of an aqueous solution of LiNO3 Co(NO3)2.6H2O citric acid and urea at 80 C followed by calcination at low temperatures. They also found that topotactic delithiation of spinel Li1+yCo2O4 by dilute aqueous sulfuric acid treatment leads to a lithium-deficient spinel Li1+y-xCo2O4 (0 ≤ x ≤ 0.6) that has a surface area and catalytic activity similar to those of the parent material. The activity of the prepared materials for photocatalytic water oxidation was assessed by monitoring oxygen evolution using a thermostatted Clark-type electrode. Given the ease of synthesis stability and high turnover frequency of the above-described Li1+yCo2O4 spinel catalysts and their corresponding delithiated materials these materials could be used in commercial elecrolyzers among other applications such as oxidation or functionalization of hydrocarbons.
These materials could be used in commercial elecrolyzers among other applications such as oxidation or functionalization of hydrocarbons.