Synthesis and characterization of Pt-Sn-Ce/MC ternary catalysts for ethanol oxidation in membraneless fuel cells

The present work represents the mesoporous carbon-supported Pt-Sn and Pt-Sn-Ce catalysts with different mass ratios have been prepared by co-impregnation reduction method. The prepared catalysts were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigation. The XRD patterns of prepared Pt/MC (100) Pt-Sn/MC (75:25), Pt-Ce/MC (75:25), and Pt-Sn-Ce/MC (75:20:05) catalysts showed that Pt metal was the predominant material in all the samples, with peaks attributed to the face-centered cubic (fcc) crystalline structures. Additionally changes in the lattice parameters observed for Pt suggest the incorporation of Sn into the Pt crystalling structure with the formation of an alloy mixture with the SnO2 phase. The TEM analysis designates that the prepared catalysts had similar particle morphology, and their particle sizes were 2-5 nm. The electrochemical studies showed that ternary catalyst shows best performance for oxidation of ethanol molecule at normal temperature. The enhanced ethanol oxidation activity for the ternary Pt-Sn-Ce catalyst is mainly attributed to the synergistic effect of bifunctional mechanism with electronic effect. Additionally, chemical nature of ceria affords oxygen-containing molecule to oxidize acetaldehyde to acetic acid. In this present context, 1 M ethanol was used as a fuel, 0.1 M sodium perborate was used as an oxidant, and 0.5 M sulfuric acid was used as an electrolyte. In mesoporous carbon-supported binary Pt-Sn and ternary Pt-Sn-Ce anode catalysts were effectively tested in a single membraneless fuel cell at normal temperature. The presence of Sn and Ce enhances the CO oxidation; they produced an oxygen-containing species to oxidize acetaldehyde to acetic acid.