Preparation of tungsten carbide-supported nano Platinum catalyst and its electrocatalytic activity for hydrogen evolution

摘要

Using ammonium metatungstate (AMT) which was treated by Spay Drying as precursors, the tungsten carbide (WC) powders with meso-porosity was prepared by gas-solid reaction in the CH_4/H_2 atmosphere. The WC-supported nano platinum (Pt) catalyst was prepared by impregnation method with the as prepared WC and H_2PtCl_6. SEM and XRD results show that the average diameter of the Pt particle which well dispersed on the surface of Pt/WC is about 13.5 nm. The electrocatalytic properties and chemistry stability of the Pt/WC powder microelectrode (PME) for the hydrogen evolution reaction in acid solution were investigated by using the electrochemical techniques of cyclic voltammetry and linear sweep voltammetry. The results show that the Pt/WC-PME exhibited an attractive catalytic activity in hydrogen evolution with a = 0.29 V. The exchange current density of hydrogen evolution is 4.42 × 10~(-3) Acm~(-2) . When the over-potential is 250 mV, the activation energy of hydrogen evolution is 26.20 kJ mol~(-1).