Intrinsically stable in situ generated electrocatalyst for long-term oxidation of acidic water at up to 80 °C

Electrochemical water splitting in acidic conditions offers important advantages over that in alkaline systems, but the technological progress is limited by the lack of inexpensive and efficient anode catalysts that can stably operate at a low pH and elevated temperature. Here we demonstrate oxygen evolution catalysts that are based on non-noble metals, are formed in situ during electrooxidation of acidic water and exhibit a high stability in operation due to a self-healing mechanism. The highly disordered mixed metal oxides generated from dissolved cobalt, lead and iron precursors sustain high water oxidation rates at reasonable overpotentials. Moreover, utilizing a sufficiently robust electrode substrate allows for a continuous water oxidation at temperatures up to 80 °C and rates up to 500 mA cm−2 at overpotentials below 0.7 V with an essentially flat support and with no loss in activity. This robust operation of the catalysts is provided by the thermodynamically stable lead oxide matrix that accommodates homogeneously distributed catalytic dopants. Electrochemical water splitting in acidic conditions is limited by the lack of inexpensive and stable anode catalysts. Now, Simonov and colleagues report a non-noble metal-based oxygen evolution catalyst formed in situ that exhibits high stability for acidic water oxidation due to a self-healing mechanism.