Carbon-modified multicomponent-doped Cr₂O₃ oxide: An efficient and ultra stable electrocatalyst for oxygen evolution reaction and water splitting

Oxygen evolution reaction (OER) plays an important role in the energy conversion industry. Despite the prevalent reliance on noble metals for their superior catalytic attributes, their high cost and limited availability present significant challenges. Reducing the use of noble metals in catalysts while maintaining catalytic activity and stability in various chemical environments is a major challenge in heterogeneous catalysis. In this study, we have strategically enhanced the catalytic performance of the Cr₂O₃ oxide by introducing multiple transition metal dopants to modulate its electronic structure. It is found that doping Ni/Co/Cu/Ru into the Cr₂O₃ oxide results in the best OER performance, which outperforms RuO₂ and other reported materials. We further improved the cycling stability of the multi-component catalyst by coating amorphous carbon on its surface. Specifically, with an OER overpotential of merely 210 mV at 10 mA cm⁻² and a low Tafel slope of 59.5 mV dec⁻¹, the catalyst exhibits remarkable catalytic efficiency. More importantly, it can withstand high current tests exceeding 100 mA cm⁻² for over 80 h without significant degradation of its OER catalytic performance. In addition, the catalyst exhibits exceptional hydrogen evolution reaction (HER) performance which is close to Pt/C, making it suitable for use as a bifunctional water splitting device. These findings have opened up a new field for the design and application of multi-component catalysts.