Simple Modification to Minimize Ionomer Poisoning in Carbodiimide Synthesized Pt-Rare Earth Catalysts
Year: 2026
Type: preprint
Abstract: Platinum rare earth (Pt-RE) alloys show promise as oxygen reduction reaction catalysts due to their improved activity and durability over conventional Pt-based catalysts. However, their synthesis has remained relatively complicated due to REs high affinity for oxygen. Recently, carbodiimide-mediated synthesis has shown promise under relatively moderate conditions, although it results in nanoparticle formation mostly on the carbon support exterior. We introduce a simple “wet-mix” modification that allows metallic precursors to diffuse into the pores of the Ketjenblack support as nucleation sites, affording a larger proportion of nanoparticles inside of the pores of the carbon black. XRD, HR-TEM, XPS and XAS, indicate higher Pt 2 Gd formation for the conventional carbodiimide route; our synthesis produces Pt 2 Gd with a small fraction of polycrystalline PtGd. Rotating-disk electrode studies showed that a high ionomer loading does not depress the mass activity, specific activity, or ECSA of the wet-synthesized catalyst. We validate this work in 12 cm 2 single-cell PEMFC studies under H 2 /O 2 , with specific activity improvement of 2.27×, and mass activity improvement of 3.04×. While the durability of the catalyst has not significantly improved, we propose reduced ionomer poisoning of the Pt 2 Gd catalyst resulting from our simple “wet-mix” modification to the carbodiimide route improves ORR activity.
Source: ChemRxiv
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7222926581