Synthesis and characterization of novel high-performance composite electrocatalysts for the oxygen evolution in solid polymer electrolyte (SPE) water electrolysis

Novel Ru0.3Ir0.7O2/Pt-0.15 composite electrocatalysts for the oxygen evolution in solid polymer electrolyte (SPE) water electrolysis were prepared by a two-step method. The intermediate Pt black with or without heat treatment (the final samples marked as C-1 and C-2 respectively) was firstly synthesized by a conventional reduction method with ultrasonic dispersion. The composite electrocatalysts were then prepared by impregnation-reduction method with ultrasonic dispersion followed by fusion treatment. The influence of heat treatment of intermediate Pt black on the properties of the composites was explored. The as-prepared composites were characterized by XRD, BET, SEM, EDX, CV and LP. The catalytic performance of the as-prepared electrocatalysts has also been investigated in a 20 cm(2) SPE electrolytic cell using Nafion (R) 117 as an electrolyte with the loading of noble metals of 1.8 mg cm(-2) at anode and 0.3 mg cm(-2) at cathode. It shows that the catalytic performance of samples C-1 and C-2 is obviously higher than that of commercial PtIrO2 electrocatalyst and the catalytic activity of C-1 electrocatalyst for the oxygen evolution is evidently higher than that of C-2 electrocatalyst in the whole range of cell voltage. The cell voltage was only 1.76 V and 1.90 V when the current density is 1.0 A cm(-2) and 1.5 A cm(-2) respectively using sample C-1 as anode electrocatalyst. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.