Study On Novel Oxygen Evolution Electrocatalyst Loaded On SiC For Solid Polymer Electrolyzer

Compared with the traditional alkaline water electrolysis technology, the solid polymer (SPE) water electrolysis technology has great advantages in high efficiency and product purity, which is extensively applied in hydrogen production, astronautics, military etc. The preparation of oxygen electrode catalyst with high activity and good stability has been one of the key questions for SPE electrolysis. At present, the related researches of SPE oxygen electrode catalyst have been mainly focused on Pt, Ir, Ru or their oxides, however, the high cost of these noble metal catalysts restrict the commercialization of SPE water electrolysis technology.In order to reduce the cost of the SPE water electrolysis technology, the research of loaded catalyst to reduce the noble metal amount is an important direction. The RuO₂ and RuO₂-IrO₂ catalysts loaded on nano-powders of TiN, TiC and SiC with high relative surface were prepared and the products were characterized by X-diffraction spectroscopy (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Their behaviors as anodic electrocatalyst for the SPE electricity analysis were investigated by electrochemical method.The results indicate that TiN and TiC nano-powders experienced were oxidized and changed into TiO₂ partially under high temperature calcination, however, SiC had better thermal stability. The oxygen evolution abilities of RuO₂/SiC, RuO₂/TiC and RuO₂/TiN were then evaluated and the results show that the RuO₂/SiC catalyst has a better catalysis performance in oxygen evolution which makes SiC be a potential candidate as the carriers of loaded-type electrocatalyst.RuO₂/SiC catalysts with different RuO₂ contents were prepared by the colloid sedimentation and their oxygen evolution abilities were also evaluated. The appearance of ruthenium in the catalyst which is harmful to the electrochemical performance of the obtained electrode could be restrained via the colloid sedimentation compared with the traditional dipping-thermal decomposition method. Furthermore, the oxygen evolution abilities were affected by the content of RuO₂, The particle size and the oxygen evolution abilities of the obtained catalyst increased along with the increment of RuO₂ content. IrO₂-RuO₂ catalyst loaded on SiC was further prepared by colloid precipitation method to enhance the stability of RuO₂. The study indicates that the solid solution of RuO₂-IrO₂ can be deposited on the surface of SiC with good combination.The noble metal catalysts for oxygen evolution loaded on SiC will become one kind of prospective catalysts in the application of SPE water electrolysis.