Investigation of the Graphene Supported Platinum-Tungsten Catalysts Prepared by Microwave Synthesis as Electrocatalysts for Borohydride Oxidation

In the study presented herein a rapid microwave heating method was used to prepare the graphene supported platinum-tungsten catalysts (denoted as Pt-W/GR) with the different Pt:W molar ratios. The prepared catalysts were characterized by means of Transmission Electron Microscopy, X-ray diffraction and Inductively Coupled Plasma Optical Emission Spectroscopy. The electrocatalytic properties of the Pt-W/GR catalysts towards the oxidation of borohydride in an alkaline medium were investigated by means of cyclic voltammetry and chrono-techniques.

It was found that the graphene supported platinum-tungsten catalysts with the Pt:W molar ratios equal to 1.6:1, 2.4:7 and 7.1:1 were prepared by microwave-assisted heating of Pt(IV) and W(VI) salts in ethylene glycol solutions.

It has been determined that the synthesized Pt-W/GR catalysts with the different Pt:W molar ratios show an enhanced electrocatalytic activity towards the oxidation of H₂ generated by catalytic hydrolysis of BH₄^– and direct oxidation of BH₄^– comparing with the graphene supported bare W catalyst. The Pt-W/GR catalyst having the Pt:W molar ratio equal to 7.1:1 exhibits the highest electrocatalytic activity for the both oxidation reactions of H₂ and BH₄^– ions as compared with that at the Pt-W/GR catalysts with the Pt:W molar ratios equal to 1.6:1 and 2.4:1.