(515k) Amorphous Cobalt-Cerium Binary Metal Oxides As High Performance Electrocatalyst for Oxygen Evolution Reaction

The amorphous Co-Ce binary metal oxides Co_1-yCe_yO_x prepared by the photochemical metal-organic deposition (PMOD) method are developed as high performance electrocatalysts for oxygen evolution reaction (OER). The influence of Ce content on the OER activity is investigated in terms of geometric and electronic factors. Ce can remarkably enhance the OER activity of CoO_x due to the synergistic effect of surface area, Co³⁺ content, and metal-OH bond strength when the content of Ce is less than 60%. Co_0.9Ce_0.1O_x supported on fluorine-doped tin oxide (FTO) coated glass substrate shows overpotential of 320 (2) mV at 10 mA cm^-2 in 1 M KOH solution. The OER mechanism exploration reveals that the rate determining step changes with the Ce content due to the variation of metal-OH bond strength. This work sheds light on the design of high-performance yet cost-effective OER catalysts.