Electrocatalytic Performance of Pd/SnO2-TiO2/MWCNT Catalyst for Oxidation of Ethylene Glycol in Alkaline Media

A novel Pd/SnO2-TiO2/multiwalled carbon nanotube (MWCNT) catalyst was synthesized using a facile and controllable in situ chemical method. Pretreated TiO2 was anchored to a functional MWCNT template, which was used as a support material to enhance the stability and electrical conductivity of the Pd nanoparticles. The Sn(II) ions adsorbed on the surface of the TiO2 precursor acted as reducing agents and ensured that Pd reduction only occurred on the precursor surface. The physicochemical properties of the catalyst were determined by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that small metallic Pd nanoparticles were evenly dispersed over the catalyst surface. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were used to evaluate the electrocatalytic properties of the Pd/SnO2-TiO2/MWCNT catalyst in an alkaline solution containing 0.5 M NaOH and 1.0 M ethylene glycol. The high dispersion of the metallic Pd nanoparticles caused by the presence of the SnO2-TiO2 precursor significantly enhanced the electrocatalytic activity and tolerance of the catalyst to the accumulation of carbonaceous species. This new Pd/SnO2-TiO2/MWCNT catalyst is a promising candidate for use in the oxidation of ethylene glycol under alkaline conditions.