Performance of MnO2-0.39IrOx composite oxides for water oxidation reaction in acidic media
MnO2-0.39IrOx(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 electrochemi-cal measurement,MnO2-0.39IrOx 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 MnO2-0.39IrOx 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 MnO2-0.39IrOx 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 MnO2-0.39IrOx 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 perfor-mance of the catalyst.
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