On the design of Pt based catalysts. Combining porous architecture with surface modification by Sn for electrocatalytic activity enhancement

• Published in: Journal of power sources 2015-05, Vol.282, p.34-44
• Main Authors: Flórez-Montaño, Jonathan, García, Gonzalo, Rodríguez, José L., Pastor, Elena, Cappellari, Paula, Planes, Gabriel A.
• Format: Article
• Language: English
• Subjects: CO oxidation; DEMS; DMFC; Mesoporous electrodes; Methanol oxidation; Pt-based materials
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.02.018

Metallic mesoporous (MP) catalysts with large surface area can be obtained in-situ, in a single step, by electrochemical reduction. In this work, the electrochemical behavior of MPPt and Sn modified mesoporous Pt (MPPt/Sn) was studied and compared with commercial carbon supported PtSn alloy (3:1). The electrochemical activity toward carbon monoxide and methanol oxidation reactions were evaluated by cyclic voltammetry and chronoamperometry, whereas X-ray photoelectron spectroscopy was used to determine the surface composition and oxidation state of the atoms in the top layers of the catalysts. The analysis of methanol conversion to CO2 was performed with aid of differential electrochemical mass spectrometry (DEMS). Results reveal a better performance of the MPPt/Sn, which shows higher current density and energy conversion efficiency of fuel to CO2 than conventional carbon supported PtSn alloy (3:1). [Display omitted] •Mesoporous Pt material (MPPt) was successfully modified by Sn adatoms (MPPt/Sn).•The CO tolerance was evaluated at MPPt, MPPt/Sn and commercial Pt3Sn/C catalysts.•The catalytic activity toward methanol oxidation for all electrodes was evaluated.•CO and methanol oxidation reactions were studied at 25 and 60 °C by DEMS.•Energy conversion efficiency from methanol to CO2 for all catalysts was calculated.