MnO2-0.39IrOx复合氧化物用于酸性介质中水氧化反应的性能

通过Adams方法成功制备MnO₂-0.39IrO_x(0.39为Ir/Mn的原子比)催化剂并将其用于酸性介质中高效析氧反应(OER)。电化学测试发现，MnO₂-0.39IrO_x仅需253 mV的过电势即可驱动10 mA·cm^-2的水氧化电流密度，并可稳定运行200 h。在1.50 V(vs RHE)电势下，MnO₂-0.39IrO_x的贵金属Ir的质量活性为61.3 mA·mg^-1，是IrO₂的35.8倍，说明MnO₂掺杂大大提升了贵金属利用率。结构分析发现MnO₂-0.39IrO_x独特的片状结构大幅度提高了催化剂的电化学活性表面积，并且Ir位点与Mn位点之间存在一定的电子相互作用。催化过程分析表明，MnO₂-0.39IrO_x表面出现一定的重构现象，并且Mn组分对Ir位点的化学环境实现了持续优化，从而实现了催化剂的高效酸性OER性能。

Performance of MnO2-0.39IrOx composite oxides for water oxidation reaction in acidic media

MnO₂-0.39IrO_x (0.39 was the atomic ratio of Ir/Mn) catalysts were successfully prepared by the Adams method and applied for efficient oxygen precipitation reaction (OER) in an acidic medium. During the electrochemical measurement, MnO₂-0.39IrO_x enabled the water oxidation process to reach a current density of 10 mA·cm^-2 with an overpotential of only 253 mV and maintained a stable test for more than 200 h. In addition, the noble metal Ir mass activity of MnO₂-0.39IrO_x was 61.3 mA·mg^-1 at a potential of 1.50 V (vs RHE), which was 35.8 times higher than that of IrO₂, increasing the precious metal utilization. Structural analysis revealed that the unique lamellar structure of MnO₂-0.39IrO_x substantially improves the electrochemically active surface of the catalysts and that there are certain electronic interactions between the Ir sites and the Mn sites. The analysis of the catalytic process showed that the MnO₂-0.39IrO_x surface showed some reconfiguration phenomenon and the Mn components achieved a continuous optimization of the chemical environment of the Ir sites, which led to the efficient acidic OER performance of the catalyst.