Effect of Sn content on Pt/CNT electrocatalysts for direct ethanol fuel cell application

Abstract

Several bimetallic PtSn catalysts supported on multiwalled carbon nanotubes for ethanol electro‐oxidation were prepared by conventional impregnation‐reduction method. The Pt loading was kept at 20 wt.% and Pt:Sn atomic ratios of 5:1, 3:1, and 1:1 were selected. The catalysts were structurally characterized by temperature programmed reduction, X‐ray diffraction, X‐ray photoelectron spectroscopy, H2 chemisorption, cyclohexane dehydrogenation reaction, and transmission electron microscopy. The electrochemical characterization of the electrocatalytic materials was carried out in acid medium by cyclic voltammetry, linear sweep voltammetry, chronoamperometry, and CO stripping techniques. Among the different stoichiometries tested, the Pt(20)Sn(12.17)/CNT catalyst exhibited the highest electrocatalytic activity for ethanol oxidation reaction, with mass current density of 189.5 mA mgPt−1 at 796 mV (vs. Ag/AgCl).

Diminishing Performance of Pt/CNT in Ethanol Oxidation after High-Potential Scanning

“…In the realm of nanoparticles, particularly those with ultrafine sizes, the high surface energy tends to lead to rapid aggregation, which negatively impacts the durability of electrocatalysts. Thus, an ideal catalyst support should provide a substantial surface area for effective catalyst immobilization and exhibit high electrical conductivity to facilitate the transport of electrons and reactants [28][29][30][31][32]. For instance, Ramachandran et al [33] illustrated that chemical strategies using ultrafine-sized PtCu/NrGO nanocomposites yield superior electrocatalytic activity for alcohol reactions.…”

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

“…Selecting Sn as the second metal, PtSn over various carbon nanocomposites has been investigated. These catalysts have been prepared through the use of diverse deposition methods and used as anodic electrocatalysts for the oxidation of low molecular weight alcohols and other small fuel molecules [13–16,25,33–44] obtaining different results.…”