Graphene supported platinum–cobalt nanocomposites as electrocatalysts for borohydride oxidation

• Preparation of graphene supported PtCo catalysts via microwave heating.
• Graphene supported PtCo catalysts for the oxidation of H2 and BH4−BH4− ions.
• PtCo/GR exhibit higher activity towards the oxidation of H2 and BH4−BH4− comparing with Pt/GR and Co/GR.

In the study presented herein a rapid microwave heating method was used to prepare the graphene supported PtCo catalysts with Pt:Co molar ratio 1:7, 1:22 and 1:44. The transmission electron microscopy was employed to characterize the catalysts. Inductively coupled plasma optical emission spectrometry was used for estimation of Pt and Co metal loadings. The electrocatalytic activity of the synthesized catalysts towards the oxidation of borohydride was investigated by means of cyclic voltammetry and chronoamperometry. The kinetics of the catalytic hydrolysis of NaBH4 in the presence of the synthesized catalysts was investigated.It has been determined that the synthesized graphene supported PtCo catalysts show an enhanced electrocatalytic activity towards the oxidation of H2 generated by catalytic hydrolysis of BH4−BH4− and direct oxidation of BH4−BH4− ions comparing with the graphene supported bare Pt catalyst and graphene supported bare Co catalyst. The graphene supported PtCo catalyst having the Pt:Co molar ratio 1:44 exhibits the highest electrocatalytic activity for the both oxidation reactions of H2 and BH4−BH4− ions.