Highly active Pd/WO3-CNTs catalysts for formic acid electrooxidation and study of the kinetics

The new Pd/WO3-CNTs catalysts are prepared for formic acid electrooxidation in direct formic acid fuel cells (DFAFCs). According to XRD, TEM, and HRTEM results, WO3 particles are covered or overlapped with Pd particles, which have a uniform and narrow size distribution due to the highly dispersion of WO3-CNTs. The electrochemical results show significantly enhanced electrocatalytic performances for formic acid oxidation on Pd/WO3-CNTs catalysts, especially its dramatically improved stability and excellent tolerance to CO poisoning, which is mainly ascribed to the interaction between Pd and WO3. Therefore, Pd/WO3-CNTs catalysts show the great potential as less expensive and more efficient electrocatalyst for DFAFCs. Additionally, the kinetic parameters such as the charge transfer parameter and the diffusion coefficient of formic acid electrooxidation on 20 %Pd/20 %WO3-CNTs were obtained.