Amorphous Cobalt Vanadium Oxide as a Highly Active Electrocatalyst for Oxygen Evolution

作者：Liardet, Laurent; Hu, Xile^*

来源：ACS Catalysis, 2018, 8(1): 644-650.

DOI：10.1021/acscatal.7b03198

• oxygen evolution reaction
• cobalt vanadium oxide
• electrocatalyst
• volcano plot
• amorphous materials

The water-splitting reaction provides a promising mechanism to store renewable energies in the form of hydrogen fuel. The oxidation half-reaction, the oxygen evolution reaction (OER), is a complex four-electron process that constitutes an efficiency bottleneck in water splitting. Here we report a highly active OER catalyst, cobalt vanadium oxide. The catalyst is designed on the basis of a volcano plot of metal-OH bond strength and activity. The catalyst can be synthesized by a facile hydrothermal route. The most active pure-phase material (a-CoVOx) is X-ray amorphous and provides a 10 mA cm(-2) current density at an overpotential of 347 mV in 1 M KOH electrolyte when immobilized on a flat substrate. The synthetic method can also be applied to coat a high-surface-area substrate such as nickel foam. On this three-dimensional substrate, the a-CoVOx catalyst is highly active, reaching 10 mA cm(-2) at 254 mV overpotential, with a Tafel slope of only 35 mV dec(-1). This work demonstrates a-CoVOx as a promising electrocatalyst for oxygen evolution and validates M-OH bond strength as a practical descriptor in OER catalysis.

• 出版日期2018-1