High performance Pt–Nb2O5/C electrocatalysts for methanol electrooxidation in acidic media

Abstract

Nb2O5 incorporated Vulcan carbon XC-72R is prepared by solid-state reaction under intermittent microwave heating (IMH) method and the Pt nanoparticles were dispersed by microwave-assisted polyol process. The electrocatalyst samples were characterized by PXRD, TEM, XPS and the performance for methanol electrooxidation was studied in 0.5molL−1 H2SO4 aqueous solutions by cyclic voltammetry, chronopotentiometry and chronoamperometry. The physicochemical characterization reveals that Nb2O5 and Pt nanoparticles were evenly deposited on Vulcan carbon XC-72R. Electrochemical experiments showed that methanol electrooxidation performance is dependent on the amount of Nb2O5 loading and the peak current densities of methanol electrooxidation is significantly higher (∼80%) on Pt–Nb2O5(2:2)/C than Pt–Ru(2:1)/C. Furthermore, Pt–Nb2O5(2:2)/C electrocatalyst exhibited slower current decay with time than Pt–Ru(2:1)/C, suggesting good tolerance behavior towards CO-like intermediates. The enhanced electrode response is attributed to the synergistic effect between Pt and Nb2O5. This work shows that Pt–Nb2O5/C is a promising anode catalyst for direct methanol fuel cells in terms of its activity and stability towards methanol electrooxidation.