上海科技大学知识管理系统

Developing inexpensive, efficient, and stable electrocatalysts for oxygen evolution reaction (OER) is crucial in energy conversion devices. The high cost and insufficient stability of the state-of-the-art IrO2 electrocatalysts for OER have restricted their widespread applications. In this work, La1-xPrxCoO3 perovskites with different Pr doping concentrations (x = 0, 0.25, 0.5, 0.75, 1) were investigated as alternative and inexpensive OER electrocatalysts. The OER activity was observed to increase with Pr doping and was maximum at the 50 mol % doping concentration. The overpotential of La0.5Pr0.5CoO3 was reduced to 312 mV at 10 mA.cm(-2), which was significantly smaller than 371 mV of LCO and even superior to that of the commercial IrO2 catalysts (341 mV). Furthermore, La-0.5Pr0.5CoO3 showed more stable performance in long-term tests compared with Pr0.5Ba0.5CoO3 and La0.6Sr0.4CoO3. X-ray diffraction analysis showed phase transition from a rhombohedral to an orthorhombic structure with Pr doping. Based on X-ray photoelectron spectrum analysis, the enhanced OER activity of La0.5Pr0.5CoO3 was correlated to electron occupation close to the Fermi level and the hybridization of O 2p and Co 3d bands, which facilitated the electron transfer process of the OER. Our work is therefore expected to provide a facile method of designing high-performance and stable OER perovskite catalysts through an approach based on electronic occupation regulation.