Construction of highly durable electrocatalysts by pore confinement and anchoring effect for the oxygen reduction reaction

Abstract

Developing highly stable and efficient catalysts for the oxygen reduction reaction is important for the long-term operation of proton exchange membrane fuel cells. Herein, combined with the impregnation method, chains of N-doped carbon spheres with abundant pores synthesized by a simple and versatile nanoemulsion assembly strategy have been used to prepare platinum catalysts (Pt-PC-300) via pore confinement and anchoring effect, which enhances the interaction between the metal and the carbon support and thus hinders the metal agglomeration and fall off during the catalytic process. The structure and composition of the materials were characterized by HRTEM, XRD, BET, TEM, SEM, XAS and XPS. Under acidic conditions, Pt-PC-300 showed better catalytic performance in oxygen reduction reaction (ORR) than Pt supported by carbon (XC-72) and commercial Pt/C. Specifically, the Pt-PC-300 catalyst exhibited a similar half-wave potential but much better stability in comparison with the commercial Pt/C because of the pore-confined structure and anchoring effect, the synergy of which provides a new way to develop stable ORR catalysts.