Abstract:

Anode electrode in proton exchange membrane （PEM） water electrolysis suffers a strongly oxidative environment under high cell voltage. At the same time， due to the high price of iridium， developing oxygen evolution electrode with low cost， high activity and stability is facing great challenges. In this paper， iridium catalyst is dispersed on WO₃ nano-array by facile operation of impregnation method. The obtained Ir@WO₃ electrode shows well activity and huge potential for application in PEM electrolytic water oxygen evolution electrode. By optimizing impregnation amount of iridium precursor， electrode exhibits disordered and porous structure with homogeneous Ir distribution at 0.15 mg_Ir·cm^-2. The related membrane electrode exhibits a single-cell performance of 2.3 A·cm^-2 at 2.0 V and tafel slope in mass transfer region of 360 mV·dec^-1. This electrode reveals obvious advantages in improving Ir mass activity （15.5 A·g_Ir^-1 at 2.0 V） and reducing mass transfer resistance， whose Ir mass activity is superior to sprayed Ir black electrode. The mentioned preparation method and structure design in this study have certain value to establish the low-cost and high activity PEM water electrolysis electrode.

Key words: PEM water electrolysis, anode catalyst, ordered array, immersion