Investigate on ionomer adsorption behavior of high specific surface area mesoporous support for proton exchange membrane fuel cell.

Carbon support has an important influence on the catalyst ink properties. The interaction between carbon support, solvent, and ionomer determines the dispersion of ink clusters. In this study, the effects of dispersion time, solvent, and ionomer on the cluster properties are studied. It is found that the shear time of 8 h is conducive to the fragmentation of catalyst particles, and isopropanol and ionomer D2020 has good dispersion for mesoporous carbon support with high specific surface area. The median diameter of catalyst clusters is effectively reduced from 1537 to 1014 nm, and 10 wt% solid content of ink is more conducive to slit coating. The increase of the ionomer content is helpful to reduce the catalyst layer cracks. When the mass ratio of dry ionomer to carbon(I/C) is larger than 0.85, the cracks of the catalyst layer are significantly reduced. The results of I–V curve tests show that when I/C = 0.85, the cell has the best polarization performance. The single cell voltage is 0.709 V at 1 A cm−2, and the power density is 1128.51 mW cm−2 at 2 A cm−2. The results of electrochemical impedance spectroscopy (EIS) are also consistent with the polarization curve test results. • The influence of ionomer on catalyst ink and fuel cell performance are analyzed. • The clusters size, Zeta potential and rheology of the ink are investigated. • The shear time, type of solvent and ionomer of the ink are optimized. • The I/C ratio and the solid content of the ink are optimized. • MEA with optimized parameters has good electrochemical performance. [ABSTRACT FROM AUTHOR]