Effect of the Preparation Method on the Electrocatalytic Activity of Pt-Sn/Nanotubes Catalysts Used in DMFC

Abstract

A series of bimetallic Pt-Sn catalysts supported on multiwalled carbon nanotubes (NT) for methanol oxidation reaction was prepared by different methods that involve ethylene glycol synthesis under reflux conditions and sodium borohydride reduction (using water or ethylene glycol as solvents) at 55 • C. Pt-Sn/NT catalysts containing 20 wt% platinum with Pt:Sn atomic ratios of 5:1, 3:1 and 1:1 were prepared and their morphology and electrocatalytic activities were characterized by temperature programmed reduction, X-ray photoelectron spectroscopy, H 2 chemisorption, benzene hydrogenation reaction, transmission electron microscopy, cyclic voltammetry, linear sweep voltammetry, chronoamperometry and CO stripping. The electrocatalysts performance depends strongly on the preparation method and Pt:Sn atomic ratios, with the Pt 3 Sn 1 /NT sample prepared by ethylene glycol displaying the highest activity for methanol electrooxidation, a good CO tolerance and an important stability.

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

“…A very low amount of Sn(0) (12 %) was found, with this small metallic fraction possibly forming alloys with metallic Pt. Similar results were found by Rodriguez et al [39] . This result indicates that Sn mainly exists in the form of SnO, SnO 2 , or Sn hydroxides.…”

“…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][14][15][16]25,[33][34][35][36][37][38][39][40][41][42][43][44] obtaining different results.…”

Controlled synthesis of mono- and bimetallic Pt-based catalysts for electrochemical ethanol oxidation

“…Monometalic and bimetallic Pt-based catalysts were synthesized following the reduction-bysolvent method [35], adapting a previously published procedure [41,42]. A typical synthesis stepwise procedure is described with details below (see Scheme 1).…”

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

“…Therefore, the addition of promoters to platinum mitigates Pt poisoning. [14][15][16] In this manner, several types of bimetallic Pt-M catalysts such as M = Ru, [17][18][19][20] Zn, [21] Fe, [22] Co, [23] Ni, [24][25][26] Sn, [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Pr, [41] , Rh, [37] and Pd [42] have been investigated as a replacement for pure Pt anodic catalyst in DEFC.…”