Synthesis of TiO2Nanoparticles Loaded Pd/CuO Nanoporous Catalysts and Their Catalytic Performance for Methanol, Ethanol and Formic Acid Electro-Oxidations

In this study, a series of nanoporous Pd/CuO/xTiO2 (np-Pd/CuO/xTiO2) hybrid catalysts were fabricated by a chemical dealloying method with a simple chemical deposition. These catalysts were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), raman spectrometry, and X-ray photoelectron spectroscopy (XPS). The cyclic voltammetry (CV) and chronoamperometry (CA) tests were carried out to determine the electro-oxidation properties. The np-Pd/CuO/160TiO2 shows superior activities for the oxidation of small organic molecules and the corresponding current densities are 2.86 mA cm−2, 7.05 mA cm−2 and 9.93 mA cm−2 for the electro-oxidation of methanol, ethanol and formic acid, respectively. A probable bifunctional mechanism was suggested as: TiO2 nanoparticles would act as a supplementary material, and oxygen-containing groups generated on the TiO2 surface could promote oxidation of the toxic intermediates. In addition, the catalytic stability of catalysts was investigated by typical electrochemical methods. The np-Pd/CuO/160TiO2 catalyst also exhibited good long-term stability.