Silica-decorated carbon-Pt electrocatalyst synthesis via single-step polyol method for superior polymer electrolyte fuel cell performance, durability and stack operation under low relative humidity

摘要

Stable hybrid silica decorated carbon composite is realized for improving oxygen reduction kinetics, performance and stability of polymer electrolyte fuel cell. Synthesis of platinum on an optimum level of silica decorated into carbon via single-step polyol method with minimum loading of platinum (0.15 mg cm(-2)) shows superior power density of 1.45 W cm(-2) in relation to platinum on carbon. The optimum composition of silica decorated carbon preserves 70% of the electrochemical active surface area of platinum even after 6000 cycles from 1 to 1.5 V. The water retention ability for silica is responsible for maintaining the humidity within the triple phase boundary of the membrane electrode assembly, which in turn increases the fuel cell performance and stability even up to 100 h under low humidity. Besides, air-cooled prototype 15 cell stack is assembled comprising the above electrocatalyst which exhibits the power output of 100 W at 10 V under 40% relative humidity.