Investigation of Solvent Effects on the Dispersion of Carbon Agglomerates and Nafion Ionomer Particles in Catalyst Inks Using Ultra Small Angle X-Ray Scattering and Cryo-TEM

摘要

In a catalyst ink, the solvent plays a critical role for the dispersion of both Nafion ionomer and Pt/C catalyst particles. In this work, different solvents were used to study the solvent effects on the dispersion of catalyst inks. The size and micro-geometry of ionomer particles and carbon black particles in different solvents were derived from the USAXS data and directly observed using cryo-TEM. It was found that the particle size of XC-72 carbon black decreased when dispersed with Nafion ionomer in ethanol and glycerol solvents. The particle size of the XC-72 dispersed in the ethanol + Nafion solvent was larger than that in the glycerol + Nafion solvent.