Preparation of Nanoporous Pd/CuO by Dealloying and Their Electrocatalysis for Methanol in Alkaline Condition

A novel and simple approach for fabrication of nanoporous Pd/CuO catalysts is reported. The nanoporous Pd/CuO catalysts were successfully prepared by chemical dealloying Ti-Cu-Pd amorphous alloy in a 1.25MHCl solution. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) tests homogeneous nanoporous structures are formed. The Pd: CuO ratio of the catalysts could be controled by adjusting the original composition of the alloy. Cyclic voltammetry (CV) and chronoamperometry (CA) were used to measure the electrocatalytic activities of the Pd/CuO catalysts. It was found that the catalytic activity was improved firstly and then depressed by increasing Pd content within both EASA and methanol electro-oxidation region. The catalyst prepared by Ti30Cu60Pd10 ribbon showed the best catalytic activity due to appropriate Pd: CuO ratio. The peak current densities in the CV curves were increased with the increase of the methanol concentration, and the catalysts maintained good electrocatalytic activities in the solution with high methanol concentration (4M). In addition, the charge transfer resistance tested by electrochemical impedance spectroscopy (EIS) decreases with the increase of CuO content, this indicates Pd : CuO ratio plays very important role in the electro-catalytic process and confirms the bifuntional mechanism of CuO. (C) The Author(s) 2014. Published by ECS. All rights reserved.