Abstract:
Methanol electrochemical oxidation in direct methanol fuel cell (DMFC) is considered as
an efficient pathway for generating renewable energy with low pollutant emissions. In this
work, NiO, CuO, Cr2O3, NiO-CuO and Ni1-x Crx O2 thin films were synthesized by a
simple dip-coating method and tested for electro-oxidation of methanol. These
synthesized electrocatalysts were characterized by X-ray diffraction spectroscopy (XRD),
Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and
Raman spectroscopy. The electro-catalytic activity for methanol oxidation was studied by
different techniques such as linear sweep voltammetry (LSV), electrochemical impedance
spectroscopy (EIS), and chronoamperometry (CA). In the presence of 0.3 M methanol,
the current densities of NiO-CuO and Ni1-x Crx O2 thin films are 6.1 mA0.5cm-2 and 6.5
mAcm-2 vs. 0.6 V. The increase in the catalytic activity of NiO-CuO and Ni1-x Crx O2 thin
films can be due to a synergistic effect between metal oxides. The findings of EIS and CA
also support the above results and help to explain the assumptions described. All the
results of NiO-CuO and Ni1-x Crx O2 thin films showed better electrocatalytic activity,
lower charge transfer resistance, good stability, and resistant to poisoning effect as
compare to pure NiO, CuO, and Cr2O3 thin films. These catalysts are less expensive and
can be a good candidate for the direct methanol fuel cell.
