Preparation of Pt/C Catalyst By Particle ALD, Fuel Cell Electrode Fabrication and Testing

Supported platinum catalysts are in common use for hydrogen fuel cells due to their efficacy for both the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). We have functionalized carbon black supports and deposited Pt nanoparticles using atomic layer deposition (ALD). In a gas-phase atomic-layer by layer process that separates the removal of organic from an organometallic, ALD was performed using trimethyl(methylcyclopentadienyl)platinum(IV) as the metal precursor reacted with either oxygen or hydrogen as the second precursor. Platinum ALD produces nanoparticles with sizes and loading depending on how many cycles are employed. The use of oxygen as a second precursor has a higher deposition rate, but particles have a larger range of sizes and are less dispersed compared to using hydrogen. Deposition on the functionalized carbon produces more uniform particle sizes and finer distribution. Electrodes were fabricated and tested. This presentation will focus on the Pt/C catalyst preparation and electrode performance using a PEM fuel cell test stand.