A low-melting-point metal doping strategy for the synthesis of small-sized intermetallic Pt5Ce fuel cell catalysts

• Published in: Nano research Vol. 17; no. 9; pp. 8112 - 8118
• Main Authors: Zou, Zi-Jun, Yin, Shi-Yi, Tang, Yao, Zhong, Sheng-Liang, Wang, Lei, Xu, Shi-Long, Liang, Hai-Wei
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.09.2024; Springer Nature B.V
• Subjects: Accelerated tests; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Cadmium; Catalysts; Cathodes; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Crystal lattices; Doping; Electrocatalysts; Electrochemistry; Electrodes; Fuel cells; Fuel technology; Gallium; Heavy metals; High temperature; Intermetallic compounds; Lanthanum; Lattice vacancies; Materials Science; Melting; Melting points; Nanoparticles; Nanotechnology; Platinum; Proton exchange membrane fuel cells; Research Article; Stability tests; Surface area; P; fuel cells; Ce; small-sized; intermetallic compound catalysis; low-melting-point metal
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-024-6800-5

Carbon-supported platinum-lanthanum (Pt-Ln) intermetallic compound (IMC) nanoparticles with high activity and robust stability have been demonstrated as promising cathode catalysts for proton-exchange membrane fuel cells. However, the preparation of Pt-Ln IMC catalysts needs high-temperature annealing treatment that inevitably causes nanoparticle sintering, resulting in significant reduction of the electrochemical surface area and mass-based activity. Here, we prepare small-sized M-doped Pt 5 Ce (M = Ga, Cd, and Sb) IMCs catalysts via a low-melting-point metal doping strategy. We speculate that the doping of low-melting-point metals can facilitate the generation of vacancies in the crystal lattice through thermal activation and thus reduce the kinetic barriers for the formation of intermetallic Pt 5 Ce catalysts. The prepared Ga-doped Pt 5 Ce catalyst exhibits a higher electrochemical active surface area (81 m 2 ·g Pt −1 ) and a larger mass activity (0.45 A·mg Pt −1 at 0.9 V) over the undoped Pt 5 Ce and commercial Pt/C catalysts. In the membrane electrode assembly test, the Ga-doped Pt 5 Ce cathode delivers a power density of 0.98 W·cm −2 at 0.67 V, along with a voltage loss of only 27 mV at 0.8 A·cm −2 at the end of accelerated stability test.