Enhanced performance for proton conducting fuel cells at low temperature

Abstract

A platinum-cobalt-iron ternary alloy is deposited on a TiO2-coated multi-walled carbon nanotube support (PtCoFe/MWCNT-TiO2) using a two-step hydrothermal method and evaluated as an anode catalyst for direct methanol fuel cells. Catalysts with different weight ratios of Pt:Co:Fe (3:1:1, 1:1:1 and 1:3:3) on MWCNT-TiO2 are prepared and examined. The Pt3Co1Fe1/MWCNT-TiO2 catalyst shows higher catalytic activity and stability compared to the 1:1:1 and 1:3:3 catalysts for the methanol oxidation reaction in acidic media. Cyclic voltammetry analysis shows a maximum mass activity for Pt3Co1Fe1/MWCNT-TiO2 of 4.17 A mg(Pt)(-1) (vs. Ag/AgCl) with a low onset potential in 0.4 M H2SO4 and 0.3 M CH3OH solution. A single fuel cell based on Pt3Co1Fe1/MWCNT-TiO2 anode catalyst exhibits a maximum power density of 117.94 mW cm(-2) at 50 degrees C in 1.3 M CH3OH, which is significantly higher than that of the Pt1Co1Fe1/MWCNT-TiO2, Pt1Co3Fe3/MWCNT-TiO2, and Pt/MWCNT catalysts. (C) 2018 Elsevier Ltd. All rights reserved.