Mn-Doped RuO<sub>2</sub> Nanocrystals as Highly Active Electrocatalysts for Enhanced Oxygen Evolution in Acidic Media
Shi Chen, Hao Huang, Peng Jiang, Yang Kang, Jiefeng Diao, Shipeng Gong, Shuai Liu, Minxue Huang, Hui Wang, Qianwang Chen
Abstract
Currently, RuO2 is a benchmark acidic oxygen evolution reaction (OER) catalyst. Nevertheless, its wide applications are always restricted by slow dynamics and limited durability. This paper reports a type of Mn-doped RuO2 nanocrystals for boosting the OER catalytic performance in acidic media. The catalyst (named Mn-RuO2) is prepared through annealing of Ru-exchanged Mn-based derivative at 300 °C. Such Mn-RuO2 exhibits excellent acidic OER activity, with an overpotential of 158 mV at 10 mA cm–2 and a stability of 5000 cycles in the presence of sulfuric acid (0.5 mol/L). Both structural characterization and theoretical analysis show that the Mn doping in RuO2 can tune the d-band center of Ru active sites and lower antibonding surface-adsorbate states, which leads to a decreased free energy of the rate-determining step, ultimately enhancing the intrinsic activity of RuO2.