The Bifuctional Electrocatalyst SiO2-SO3H Supported Pt for Unitized Regenerative Fuel Cells

Abstract

For enhance the electrochemcial performance of URFC system, the novel combination of sulfonated silica-supported Pt electrocatalyst were synthesized. The investigated electrochemical surface area values are 23.02 and 22.96 m2/g for the Pt black and 80 wt% Pt/SiO2-SO3H catalysts, respectively. The bifunctional (oxygen reduction reaction (ORR) and oxygen evolution reaction (OER)) performance in URFC system were carried out through fuel cell and water electrolyzer modes for Pt/C, Pt/SiO2, and Pt/SiO2-SO3H electrocatalysts. The determined round-trip energy conversion efficiency of Pt/C, Pt/SiO2, and Pt/SiO2-SO3H are 45.3, 44.6 and 46.1 %, respectively. Comparatively, the Pt/SiO2-SO3H electrocatalyst shows an improved electrocatalytic performance than Pt/C and Pt/SiO2 electrocatalysts. Due to presence of sulfonic acid functional group on the support material (SiO2–SO3H), the proton conduction has intensified in the catalyst layer during the URFC unit cell operation. Based on the performance data, the sulfonated silica-supported Pt electrocatalyst (Pt/SiO2-SO3H electrocatalyst) identified as a efficient bifuntional electrocatalyst material for further development in URFC applications. Key Words : Unitized regenerative fuel cell (URFC), Electrocatalyst, Sulfonated silica (s-SiO2), Oxygen reduction reaction (ORR) Figure 1