Surface-sulfonation and fuel cell properties of phenylsilsesquioxane-based particles

An inorganic–organic hybrid of phenylsilsesquioxane-silica (PhSiO3/2–SiO2) nanoparticle was prepared by sol–gel process, and a high proton-conducting electrolyte was synthesized by surface-sulfonation of phenyl groups of the particles. Chlorosulfonic acid was used as a sulfonation agent. The PhSiO3/2–SiO2 particles are chemically stable as well as flexible. The proton conductivity of the pelletized sample reached about 10− 2 S/cm at 80 °C and 80% relative humidity (RH). The open circuit voltage (OCV) of the single cell prepared using the pelletized sample as an electrolyte for a H2-air fuel cell increased with increasing the RH of the cell. The maximum power density of ~ 40 mW/cm2 and OCV of 0.9 V was obtained at 80 °C and 95% RH.