Electrocatalyst Design in Proton Exchange Membrane Fuel Cells for Automotive Application

Improved Oxygen Reduction Activity and Durability of Dealloyed PtCox Catalysts for Proton Exchange Membrane Fuel Cells: Strain, Ligand, and Particle Size Effects

“…Thus, these results indicate that both catalysts are composed of Pt-dominated surfaces and Co-rich cores. A more surface-sensitive Δμ-XANES analysis reported elsewhere shows that there is some Co in the (near)­surface regions of both catalysts under in situ conditions. Therefore, the ligand effects caused by the interactions between surface Pt and subsurface Co cannot be excluded, although it is unclear whether they play an important role in modifying the electronic properties of Pt in the surfaces of PtM NPs as compared to the concomitant strain effects. ,, …”

Impact of Nickel Ions on the Oxygen Reduction Reaction Kinetics of Pt and on Oxygen Diffusion through Ionomer Thin Films

“…Introduction of metal cations into the ionomer can occur from leaching from the Pt-base metal catalyst during electrode preparation and PEFC operation. 11,12 The amounts of base metals leached from the catalyst are significant with respect to the number of sulfonate groups in the ionomer present in the cathode catalyst layer (CCL). Myers et al found that during preparation of an ink from a commercial PtCo catalyst, 1000 equivalent weight (EW) PFSA, and an n-propanol-rich solvent, the amount of Co leached from the catalyst is enough to occupy 26% of the sulfonate groups in the CCL ionomer (ionomer to carbon ratio, I/C, of 0.9), rising to 52% for an ink comprising the same PtCo catalyst, 800 EW ionomer, and an aqueous-rich solvent (I/C = 0.7).…”