Palladium nanoparticles supported on hollow mesoporous tungsten carbide microsphere as electrocatalyst for formic acid oxidation

Hollow tungsten carbide and cobalt spheres (HTCCS) with cobalt concentration of 6% were prepared by spray conversion and reduction carbonization methods. The HTCCS with diameters of about 8-18μm were covered with 0.3-1.0μm microporous. The Pd/WC catalyst was prepared through the replacement reaction between Co nanoparticles on the surface of HTCCS and PdCl₄. The electro-catalytic performances for formic acid electro-oxidation were investigated by cyclic voltammetry and chronoamperometry. It exhibited the low onset potential, excellent catalytic activity and stability compared with Pd/C due to the larger electrochemical surface area (ECSA) and the synergistic effect between Pd and WC.