Ultralow-Pt Titanium Carbide Anode Electrocatalyst for Durable Polymer Electrolyte Fuel Cells

Abstract

Sustained operation of proton exchange membrane fuel cells (PEMFCs) at ultralow Pt loadings is limited by anode degradation: in conventional Pt/C, corrosion of the carbon support and Pt loss drive activity decay while reformate-fed and high-temperature operation add CO poisoning. Replacing the exposed carbon surface with a more robust carbide addresses both limits. Here, we report a titanium carbide (TiC) supported Pt anode in which strong Pt–TiC interactions stabilize Pt as isolated atoms and subnanometer clusters. Density functional theory (DFT) calculations show strong Pt binding on both TiC (100) and TiC (111) and spontaneous H2 dissociation at Pt–C interfacial sites. In a phosphoric acid-doped polybenzimidazole (PA-PBI) membrane electrode assembly (MEA) at 150 °C under a CO-containing H2 stream, the 1 wt % Pt/TiC anode delivers a peak power density comparable to a commercial 10 wt % Pt/C reference with four times less Pt and shows no decay over 100 h. At an ultralow loading of 0.015 mgPt cm–2, the catalyst sustains stable power density of 0.16 W cm–2 for ∼100 h in a Nafion-based MEA at 80 °C, corresponding to 10.7 WmgPt–1of anode Pt. These results identify TiC support engineering as a promising strategy for durable low-Pt anodes across low- and high-temperature PEMFCs, with improved performance retention under CO-containing feed at 150 °C.