Development of Pt-based catalysts towards methanol electrooxidation as promising materials for the anode of a direct methanol fuel cell

Abstract

One of the significant drawbacks of the Direct Methanol Fuel Cells is the overpotential for the methanol oxidation reaction, which strongly limits the efficiency of this fuel cell. Furthermore, CO poisoning of Pt is considered to be a severe problem for these devices. In this work, electrocatalysts with suitable properties and outstanding performance have been developed for the oxidation reaction of methanol. PtCu and PtCuRu type materials have been synthesized through a relatively uncomplex, fast, highly reproducible, and easily scalable method. In turn, these materials have been subjected to a selective chemical dissolution process to enrich their surface with a higher density of active sites and surface defects. Evidence of alloy formation was found, specifically through XPS measurements on Ru 3d level. Besides, it was observed that with the trimetallic catalysts, which contain not only Cu but also Ru, the onset of CO electrooxidation is substantially reduced. Moreover, the leaching treatment further improves this value. This same trend was observed in the evaluation of methanol oxidation. Regarding the specific and mass activities, PtCuRu-le exhibits almost 240% and 195% higher SA and MA than commercial Pt, respectively.