Improved mass transfer using a pore former in cathode catalyst layer in the direct methanol fuel cell

The cathode catalyst layer in direct methanol fuel cells (DMFCs) was prepared using polystyrene beads as a pore former. Field emission scanning electron microscopy showed that the catalyst layer with the pore former contained pores with a uniform shape and size. Mercury intrusion porosimetry showed that the pore former increased the volume of secondary pores in the catalyst layer. The electrochemical properties of the membrane electrode assembly (MEA) were evaluated by current–voltage polarization measurements, electrochemical impedance spectroscopy and cyclic voltammetry. These results suggest that the catalyst layer with the pore former reduces the mass transfer resistance and improves the cell performance by approximately 50% through modification of its morphology.

► Fabrication of catalyst layer with polystyrene beads as pore former in DMFC.
► The secondary pores of the catalyst layer were enhanced by the pore former.
► The modification of pore structure improves the single cell performance.