The formate electrooxidation on Pt/C and PtSnO2/C nanoparticles in alkaline media: The effect of morphology and SnO2 on the platinum catalytic activity

Abstract

Pt/C and PtSnO2/C electrocatalysts with and without cubic preferential morphology were used for formate electrooxidation reaction (FER) in alkaline medium. The synthesis of catalysts was carried out by alcohol reduction method using KBr as a shape directing agent (Bromide Anion Exchange method - BAE). The X-ray diffraction (XRD) showed characteristic peaks of the Pt face-centered cubic (FCC) structure, as well as cassiterite SnO2. The Transmission Electron Microscopy (TEM) and Scanning Transmission Electron Microscopy (STEM) micrographs show SnO2 dispersed onto carbon support and adjacent to the Pt nanoparticles (NPs), as well as cubic Pt NPs. The cyclic voltammetry (CV) measurements show that the current density peak for FER on Pt/C (100) is 2.40 times higher than on Pt/C polycrystalline (poly). The current density at end of chronoamperometry (CA) analysis on PtSnO2/C poly was 1.33 and 5.29 times higher than on Pt/C (100) and Pt/C poly, respectively. The presence of SnO2 and the (100) facets of platinum cubic morphology might prevent platinum surface deactivation caused by intermediates formed during the FER process.