Preparation and characterization of carbon-supported Pt, PtSnO2 and PtRu nanoparticles for direct methanol fuel cells

Nanosized Pt, PtSnO2 and PtRu particles were prepared by a microwave-assisted polyol process. Vulcan XC-72 was selected as catalyst support for Pt, PtSnO2 and PtRu particles. The catalysts were characterized by TEM, XRD and XPS. TEM investigations showed nanoscale particles and narrow size distribution for Pt, PtSnO2 and PtRu catalysts. All Pt, PtSnO2 and PtRu catalysts showed the X-ray diffraction pattern of a face-centered cubic (fcc) crystal structure. As evidenced by XPS, most Pt, Sn and Ru atoms in the nanoparticles were Pt(0), Sn(IV) and Ru(0). Preliminary tests on a single cell of a direct methanol fuel cell (DMFC) indicate that PtSnO2/C catalyst gave the best electrocatalytic performance among three catalysts. The cell performance was analyzed based on the measurement of the current–voltage characteristics and impedance spectroscopy in the single fuel cell.