پديدآورندگان :
Daneshvari-Esfahlan Vahid Electrochemistry Research Laboratory, Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran , Hosseini Mir Ghasem mg-hosseini@tabrizu.ac.ir Electrochemistry Research Laboratory, Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran, , Mahmoodi Rana Electrochemistry Research Laboratory, Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
كليدواژه :
methanol oxidation , Ni , Pd electrodes , Ni , Pd electrocatalyst
چكيده فارسي :
Liquid fuels such as borohydride [1], hydrazine [2] and methanol [3] solutions have been used in the direct liquid-feed fuel cell. The electro-oxidation of this fuels is kinetically slow; thus a catalyst is required to improve the efficiency of the oxidation reaction. In this work, Ni/Pd nanoparticles with particle size of 10 nm are synthesized successfully using a two-step successive reduction method. The physical characterization of Ni/Pd electrocatalyst is investigated by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Electrocatalytic properties of Ni/Pd nanoparticles towards methanol electro-oxidation are studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The results show that the catalytic activity of the Pd/Ni electrocatalyst toward methanol electro-oxidation is 4.6 times higher than that of Pd because of the synergistic effect between Pd and Ni (1450 A g-1 in presence of 0.5 mol L-1 methanol and scan rate of 100 mV s-1). Additionally, the effects of scan rate, methanol concentration and temperature dependency of methanol oxidation on Ni/Pd electrodes have been explored in this study. The results show that the methanol oxidation reaction on Ni/Pd electrocatalyst is controlled by mass transfer and this reaction has a low activation energy which leads high catalytic activity. All results show that the Ni/Pd catalyst is a good anode catalyst candidate for the direct methanol fuel cell.
