The design and synthesis of oxygen evolution reaction (OER) electrocatalysts that operate efficiently and stably under acidic conditions are important for the preparation of green hydrogen energy. The low intrinsic catalytic activity and poor acid resistance of commercial RuO₂ limit its further development, and the construction of heterointerface structures is the most promising strategy to break through the intrinsic activity limitation of electrocatalysts. Herein, we synthesized spherical and oxygen vacancy-rich heterointerface MnO₂/RuO₂ using morphology control, which promoted the kinetics of the oxygen evolution reaction with the interaction between oxygen vacancies and the oxide heterointerface. MnO₂/RuO₂ was reported to be an acidic OER catalyst with excellent performance and stability, requiring only an ultra-low overpotential of 181 mV in 0.5 M H₂SO₄ to achieve a current density of 10 mA cm⁻². The catalyst activity remained essentially unchanged in a 140 h stability test with an ultra-high mass activity (858.9 A g⁻¹@ 1.5 V), which was far superior to commercial RuO₂ and most previously reported noble metal-based acidic OER catalysts. The experimental results showed that the effect of more oxygen vacancies and the heterointerfaces of manganese ruthenium oxides broke the intrinsic activity limitation, provided more active sites for the OER, accelerated reaction kinetics, and improved the stability of the catalyst. The excellent performance of the catalyst suggests that MnO₂/RuO₂ provides a new idea for the design and study of heterointerfaces in metal oxide nanomaterials.

中文翻译：

---

具有丰富氧空位的异质界面 MnO2/RuO2 可增强酸性介质中的析氧能力

设计和合成在酸性条件下高效稳定运行的析氧反应（OER）电催化剂对于制备绿色氢能源具有重要意义。商业RuO ₂较低的本征催化活性和较差的耐酸性限制了其进一步发展，而异质界面结构的构建是突破电催化剂本征活性限制的最有前途的策略。在此，我们通过形貌控制合成了球形且富含氧空位的异质界面MnO_{​​ 2} /RuO ₂，​​通过氧空位与氧化物异质界面之间的相互作用促进了析氧反应的动力学。据报道， MnO ₂ /RuO _{2是一种具有优异性能和稳定性的酸性OER催化剂，在0.5 MH 2} SO ₄中仅需要181 mV的超低过电位即可实现10 mA cm ^-2的电流密度。该催化剂活性在140小时稳定性测试中基本保持不变，具有超高质量活性（858.9 A g ^-1 @ 1.5 V），远远优于商业RuO ₂和大多数先前报道的贵金属基酸性OER催化剂。实验结果表明，更多氧空位和锰钌氧化物异质界面的作用打破了本征活性限制，为OER提供了更多的活性位点，加速了反应动力学，提高了催化剂的稳定性。催化剂优异的性能表明MnO ₂ /RuO ₂为金属氧化物纳米材料异质界面的设计和研究提供了新的思路。