Rapid Synthesis of a Pt1Ru1/Carbon Nanocomposite Using Microwave Irradiation: A DMFC Anode Catalyst of High Relative Performance

Abstract

Thermal treatment of (η-C2H4)(Cl)Pt(μ-Cl)2Ru(Cl)(η3:η3-2,7-dimethyloctadienediyl) (1)/Vulcan carbon composites under appropriate oxidizing and reducing conditions using microwave dielectric loss heating affords PtRu/Vulcan carbon nanocomposites consisting of PtRu alloy nanoparticles highly dispersed on a powdered carbon support. Two such nanocomposites containing 16 or 50 wt % total metal and alloy nanoclusters of 3.4- or 5.4-nm average diameter are formed within only 100 or 300 s of total microwave heating. XRD and on-particle EDS analyses reveal that complex 1 serves as a reliable single-source molecular precursor for the formation of PtRu nanoparticles having a nearly 1:1 metal alloy stoichiometry. Preliminary measurements of the catalytic activity of these nanocomposites as supported direct methanol fuel cell (DMFC) anode catalysts indicate that the 50 wt % nanocomposite has a performance superior to that of a 60 wt % commercial catalyst and a normalized performance equivalent to that of a proprietary unsupported Pt1Ru1 catalyst.