The Role of a Sn Promoter on an Anodic Pt Electrocatalyst Prepared over H2O2-Functionalized Carbon Supports for Direct Ethanol Fuel Cell (DEFC) Applications

Abstract

Multiwalled carbon nanotubes and Vulcan carbon were functionalized with a 30 %v/v hydrogen peroxide solution and employed as supports for Pt and PtSn catalysts prepared by the polyol method. PtSn catalysts with a Pt loading of 20 wt.% and a Pt:Sn atomic ratio equal to 3:1 were evaluated in the ethanol electrooxidation reaction. The effects of the oxidizing treatment on the surface area and the surface chemical nature were analyzed through N2adsorption, isoelectric point, and temperature-programmed desorption measurements. Results showed that the H2O2treatment affects the surface area of the carbons to a great extent. Characterization results indicated that the performance of the electrocatalysts strongly depends both on the presence of Sn and on the support functionalization. PtSn/CNT-H2O2electrocatalyst displays a high electrochemical surface area and enhanced catalytic activity for ethanol oxidation in comparison to other catalysts in the present study.