An efficient antimony doped tin oxide and carbon nanotubes hybrid support of Pd catalyst for formic acid electrooxidation

摘要

We report on a mixture of antimony doped tin oxide (ATO) and carbon nanotubes as a novel support of Pd catalyst (Pd/ATO-CNTs) with the aims to enhance electron and proton conductivity of hybrid support, and catalytic activity and stability for formic acid electro-oxidation. The surface content, morphology and structure of the as-prepared Pd/ATO-CNTs catalysts with different CNTs contents have been characterized by X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), inductively coupled plasma-optical emission spectroscopy (ICP-OES), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and high angle annular dark field STEM (HAADF-STEM), respectively. The electrocatalytic properties of the samples for formic acid electrooxidation reaction are investigated by cyclic vol-tammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the activity and stability of Pd/ATO-CNTs catalyst is obviously higher than that of Pd/CNTs catalyst for formic acid electrooxidation due to unique physical and chemical properties of ATO and metal-support interaction between Pd nanoparticles and ATO. Moreover, the Pd/ATO-CNTs10 (CNTs content is 10 wt.% of ATO-CNTs support mass) with smaller Pd particle size and narrower size distribution on surface of the hybrid support exhibits the best performance for formic acid electrooxidation among all the samples.