Improving stability of high temperature polymer electrolyte membrane fuel cell using Nb4N5/C composite support

Abstract

The stability of support materials is crucial for the application of high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs), and the corrosion of conventional carbon support poses a significant challenge. In this study, a new type of composite support material, carbon composite niobium nitride (Nb4N5/C) was developed and investigated. Physical characterization demonstrated that Nb4N5 has a unique micro-flower morphology with a large specific surface area, making it an ideal support for Pt nanoparticles. X-ray photoelectron spectroscopy (XPS) analysis revealed that the addition of Nb4N5 reduced the displacement of d-band center of Pt and weakened the bonding between adsorbed oxygen and Pt. The Pt/Nb4N5/C-based catalyst demonstrated better stability than Pt/C after undergoing an accelerated durability test (ADT) of 5000 cycles, indicating the effectiveness of introducing this transition metal nitrides (TMNs) to enhance catalyst stability. Moreover, in the single-cell test at high temperature, the HT-PEMFC based on the Pt/Nb4N5/C catalyst exhibited an impressive peak power density of 520.48 mW cm−2 at 150 °C. After the durability test, it only suffered a decrease of 5.2%, which is more stable than the commercial Pt/C (11.7%), suggesting it is promising candidate for practical HT-PEMFC applications.