Effect of OMC and MWNTC support on mass activity of Pd Co catalyst for formic acid electro-oxidation

Autor: M. D. Morales-Acosta, E. Cazares-Ávila, F.J. Rodríguez-Varela, D. Morales-Acosta, Aracely Hernández-Ramírez, E. Ruiz-Ruiz
Rok vydání: 2017
Předmět:
Zdroj: International Journal of Hydrogen Energy. 42:30349-30358
ISSN: 0360-3199
DOI: 10.1016/j.ijhydene.2017.08.156
Popis: The electrochemical evaluation of Pd Co catalyst supported on Ordered Mesoporous Carbon (Pd Co/OMC) synthesized by the polyol method is reported in this work. OMC is synthesized via self-assembly in aqueous solution, as an alternative route to conventional preparation methods. The electrocatalytic performance of Pd Co/OMC is evaluated for Formic Acid Oxidation Reaction (FAOR). The results are compared with those of Pd Co on Multi-Walled Carbon Nanotubes (Pd Co/MWCNT) and Pd/OMC, prepared by the same procedure, with the aim to evaluate the effect of support and the Co contribution during the FAOR. The catalysts are characterized by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS). Cyclic voltammetry (CV) and chronoamperometric studies are carried out in acid media with different formic acid concentrations (0.1, 0.5 and 1 mol L−1). According to TEM results, Pd Co/OMC exhibits smaller particle size (∼3.5 nm) and enhanced distribution of nanoparticles compared with Pd Co/MWCNT. At 0.5 mol L−1 HCOOH, Pd Co/OMC delivers a higher anodic mass current density (185 mA mg−1 Pd) of the FAOR than Pd Co/MWCNT (94.3 mA mg−1 Pd). Moreover, at 1 mol L−1 HCOOH the jf/jb ratio for Pd Co/OMC is 1.09 mA mg−1 Pd, higher than the ratios determined for Pd Co/MWCNT (0.76) and Pd/OMC (0.85). The improvement of the mass catalytic activity of Pd Co/OMC is attributed to the combination of the mesoporous structure of the support, which promotes the catalyst-support interaction facilitating the mass transfer process during the reaction, and to the incorporation of Co in the Pd structure.
Databáze: OpenAIRE