A study towards superior carbon nanotubes-supported Pd-based catalysts for formic acid electro-oxidation: Preparation, properties and characterisation

This study investigates several CNT-supported Pd-based catalysts and compares their morphological as well as electrochemical characteristics for formic acid electro-oxidation. Pd/C catalysts are prepared via various impregnation methods, using different reaction media or reducing agents. The average mean particle sizes of the precipitated Pd vary from 2.6 nm to 18.0 nm. It is further shown that the particle size of Pd/C dispersions can be easily controlled by changing the solvent and experimental conditions during the preparation procedure. Measurements of catalytic activity by using cyclic voltammetry reveal strong particle size dependence of the anodic peak current density. The electro-oxidation of formic acid may be kinetically-controlled or diffusion-controlled regarding the Pd morphological characteristics.

► The influence of experimental parameters on morphology of catalyst was investigated. ► Homogeneous and heterogeneous precipitation of Pd was achieved. ► Smaller particle size of catalyst show higher specific current densities.