Study Of Electrocatalytic Properties On TiN Based IrO₂+Ta₂O₅

TiN based IrO₂+Ta₂O₅ coating electrodes and powder electrocatalyst were first prepared by thermodecomposition method in the region from 420℃to 560℃. Electrochemical and physicochemical methods have been used to investigate their morphological structure, electrocatalytic activity in comparison with Ti based coating electrodes . The electrocatalytical activity of the powder catalyst of IrO₂+Ta₂O₅ supported on nanoparticle TiN has been studied primarily for fuel cell and water electrolysis with SPE (Solid Polymer Electrolytes) technology. Some promising conclusions are as follows:In case of TiN based IrO₂+Ta₂O₅ coating anode, preparing temperature had a significant effect on their morphology and electrocatalytical activities. The XRD results showed that TiN film could be detected in the region of preparing temperatures from 420℃to 540℃, but decomposed at 560℃; The SEM and EIS results indicate that TiN based oxide layers exhibited a cracked-mud and porous morphology. Crack increased and porosity decreased with increasing the preparation temperature observed by SEM, and the electrocatalytical activity for oxygen evolution increased with decreasing the preparation temperature attained by EIS and anodic polarization curves. The results showed that Ti and TiN based coating oxides all exhibited the highest activity at 420℃. The coating anodes based on TiN have similar high electrochemical activities with the Ti-based anodes. Life time of the anode prepared at 460℃with TiN base was superior to that of the traditional Ti based coating anode. It is feasible using TiN as support for IrO₂-Ta₂O₅ coating anode.In case of TiN based IrO₂+Ta₂O₅ coating cathode, the results showed that there existed TiN substrates on the electrodes. The best electrocatalytic activity occurs at 420℃. Electrode potential for hydrogen evolution on the coating layer was -0.26 V(vs.SCE). The Tafel slope was -40 mVdec-1 in low over-potential region of hydrogen evolution. The structure...