A copper(II) coordination compound under water-oxidation reaction at neutral conditions: decomposition on the counter electrode

In the context of energy storage, the oxygen-evolution reaction (OER, 2H(2)O -> O-2 + 4H(+) + 4e(-)) through the water-oxidation reaction is a thermodynamically uphill reaction in overall water splitting. In recent years, copper(II) coordination compounds have been extensively used for the OER. However, challenges remain in finding the mechanism of the OER in the presence of these metal coordination compounds. Herein, the electrochemical OER activity is investigated in the presence of a copper(II) coordination compound at pH approximate to 7. While the investigations on finding true catalysts for the OER are focused on the working electrode, herein, for the first time, the focus is on the decomposition of copper(II) coordination compound (CuL3, L: 2,2 '-bipyridine N,N '-dioxide) during the OER on the counter electrode toward the precipitation of copper(i) oxide and metallic Cu.

Automated summary

In the context of energy storage, the oxygen-evolution reaction (OER) through water-oxidation is an uphill reaction. Copper(II) coordination compounds have been widely used for OER, but understanding the mechanism in the presence of these compounds remains a challenge. This study investigates the electrochemical OER activity of a copper(II) coordination compound at pH 7 and focuses on the decomposition process.