There is little study on the preparation of non-conductive silica support for the fuel cell. It is expected that the sulfonation site in sulfonated silica (sSiO₂) support can enhance the proton transfer property rather than the electron transfer. Therefore, we synthesize the sulfonated silica-supported Pt electrocatalyst for a bifunctional oxygen electrode in unitized regenerative fuel cell (URFC). A novel catalyst based on platinum on sulfonated SiO₂ support aims for stabilizing cycle performance of URFC. It means that the usage of alternative sSiO₂ is focused on suppressing the corrosion of support, whereas carbon support for the conventional oxygen electrode shows significant degradation in electrolyzer mode. In this study, the nano-morphology of our catalyst is confirmed by XRD and TEM. Electrochemical performances are analyzed by cyclic voltammetry (CV). Our new catalyst (46.1%) shows higher and stable performance during cyclic process due to the enhanced proton conduction property and low corrosion of the sulfonated silica support rather than the conventional Pt/C catalyst (45.3%). This means that the sulfonic acid functional group on the silica support can increase proton conductivity in the catalyst layer. Therefore, the ohmic resistance can decrease in the unit cell. Therefore, the sulfonated silica supported Pt electrocatalyst can be a promising candidate for bifunctional electrocatalyst in URFC.