Polymer electrolyte fuel cells employing electrodes with gas-diffusion layers of mesoporous carbon derived from a sol-gel route

Abstract

Sol-gel derived mesoporous carbon (MC) for the preparation of gas-diffusion layer (GDL) and its ameliorating effect on the performance of polymer electrolyte fuel cells (PEFCs) is reported. MC with a specific surface area of 370 m²/g, pore diameter of 6.7 nm and pore volume of 0.45 cm³/g has been synthesized by co-assembly of a tri-block copolymer, namely pluronic-F127, as a structure directing agent, and a mixture of phloroglucinol and formaldehyde as carbon precursor. X-ray diffraction and transmission electron microscopy have been employed to examine the structural properties of the MC. Surface morphology of the GDL comprising MC has been studied by scanning electron microscopy. A peak power density of 0.53 W/cm² at a load current-density of 1.1 A/cm² is achieved for the PEFC employing electrodes with GDL of MC compared to the peak power density of 0.47 W/cm² at a load current-density of 0.93 A/cm² for the PEFC employing electrodes with GDL of commercial Vulcan XC-72R carbon, while operating at 70 ° C with H₂ and air feeds at atmospheric pressure.