Study of the Effect of Calcination Temperature on the Morphology and Activity of Iridium Oxide Electrocatalyst Supported on Antimony Tin Oxide (ATO) for PEM Electrolyser Technology

摘要

Iridium oxide nanoparticles supported on Antimony Tin oxide (ATO) have been widely used for the oxygen evolution reaction in polymer electrolyte membrane (PEM) electrolysis. In this paper the morphology, crystallinity and performance for the oxygen evolution reaction (OER) activity of the catalyst iridium oxide supported on ATO at various calcination temperatures will be reported. The supported catalyst was synthesized using a modified Polyol method and calcined at temperatures of 200, 350, 500 and 700℃. The electrocatalysts were physically characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Brunauer, Emmett and Teller (BET) surface area measurements. The catalysts were also electrochemically characterized by cyclic voltammetry (CV) in a typical three electrode system. The main focus of this work is to study the effect of calcination temperatures on the morphology of iridium oxide nano particles as a function of temperature and degree of crystallization. We find that iridium oxide nano particles synthesized with Polyol method has amorphous structure and calcining at temperatures higher than 400℃ increases the particle size and changes its structure from amorphous to crystalline. It also was found that the amorphous iridium nano particles are highly active and efficient catalyst toward OER, while calcining the catalyst decreases the electrochemically active surface area and its activity.