Study of OER electrocatalysts performance of Fe/Mn doped pyrochlorestructure

Pyrochlore is considered as the most promising catalytic materials for its open structure and readily tuning characteristics by doping appropriate ions. In this paper, we report a simple and efficient sol-gel method to synthesizeY2Ru1.9Mn0.1O7-δ and Y2Ru1.9Fe0.1O7-δ to promote oxygen evolution. It was found that the introduction of Mn/Fe into YRO enhanced the catalytic activity. Through qualitative and quantitative analysis of oxygen vacancies by means of XPS and TG, a mass of oxygen vacancies wasintroducedin the pyrochlore structure due to exotic Mn and Fe, which act as active sites to promote catalytic performance. Subsequent stability tests found that the doped Fe ions significantly increased the stability of the structure while Mn ions are inverse. To further investigate the activity of Y2Ru1.9Mn0.1O7-δ and Y2Ru1.9Fe0.1O7-δ, the first principles calculation was used. It indicates that the lower the oxygen vacancy formation energy, the better the catalytic activity. In light of the improvement of Y2Ru1.9Fe0.1O7-δ stabilty, the first-principles calculation results show that it is due to the Fe ion presence increased the surface dissolution energy and strengthen the covalence between Ru–O of the matrix, which effectively inhibiting the exsolution of Ru.