Synthesis and stability of Pt3Co and Pt0.7≤X≤1Co films voltammetrically activated in acidic medium for methanol fuel cell application

Abstract

Pt-Co thin films have been prepared by means of electrodeposition method, due to the interest of this alloy as catalyst in acid fuel cells. As the stability of the catalyst is fundamental to consider its applicability, the behavior of the films as a function of the composition during voltammetry activation in acidic medium has been studied. The Pt3Co films show high stability, maintaining their morphology, X-ray diffraction profile, composition and high surface area, and show good catalytic behaviour for methanol electro-oxidation in acidic medium. However, the Pt0.7≤x≤1Co films present low stability and evolve during the test to flatter films of lower effective area and Pt3Co stoichiometry, by losing cobalt. Only Pt-Co electrodeposited films of defined compositions show the enough stability and properties to be used as good materials for electro-oxidation processes in acidic media.