WO3/C supported Pd catalysts for formic acid electro-oxidation activity

Pd-WO3/C ternary hybrid was designed as a high-efficient catalyst towards formic acid electrooxidation. WO3/C hybrids were first prepared with two different synthesis order, and then used as the supports to synthesize two kinds of Pd-WO3/C catalysts by a quick and facile microwave-assisted ethylene glycol method. Compared with Pd/C, the catalytic performances of two Pd-WO3/C catalysts towards formic acid electrooxidation are significantly enhanced. We elected the better synthesis order and optimized the best proportion of WO3 and C in the hybrid catalyst. When the mass content of WO3 is 20% of the mass of the support, Pd nanoparticles with narrower particle size distribution are more uniformly dispersed on the surface of WO3/C support than the other counterparts, resulting in the highest performance in terms of activity and stability towards formic acid oxidation among all the samples. The reasons for the performance improvement may be: first, Pd nanoparticles in Pd-WO3/C catalysts are of small size and evenly distributed; second, there may be the catalyst-support interaction between Pd and WO3, substantially improving the catalytic capability of Pd-WO3/C catalysts; finally, the hydrogen spillover effect produced by WO3 significantly expedites the dehydrogenation of formic acid on the surface of Pd-WO3/C. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.