Regulating the Mesoporous Structure of Carbon Nanospheres by a Local Ablation Method for High-Performance PEMFC Catalysts

Pt-based catalysts are the most widely used catalysts in proton exchange membrane fuel cells (PEMFCs). However, the catalytic activity cannot be fully expressed by the pore structure of current commercial catalysts. In this work, the pore structure of available commercial carbon black (4–7 nm), which is beneficial for Pt catalytic activity, was successfully regulated by using perchloric acid (HClO4) as a pore-forming agent. The generated carbon nanospheres are denoted as NCB (new carbon black), with a pore volume in the 4–7 nm region (V4–7 nm) increasing from 0.107 cm3/gcarbon to 0.164 cm3/gcarbon. Pt-embedded catalysts on NCB (Pt/NCB) were synthesized by the impregnation method. The Pt/NCB catalyst exhibited oxygen reduction reaction (ORR) activity comparable to that of the original porous carbon-supported Pt catalyst under the suppression of ionomers. Moreover, the proton conduction resistance of the Pt/NCB catalyst layer decreased from 78 Ω·cm2 to 57 Ω·cm2, a decrease of 26.9%. The Pt/NCB catalyst layer also displayed excellent oxygen transport performance, and the oxygen gain voltage (OGV) was lower than that of the Pt catalyst with commercial porous carbon support. Overall, the local ablation method with HClO4 as a pore-forming agent is an effective way to fabricate accessible pores on easily available commercial carbon black, contributing to highly efficient catalytic activity