In this study, graphene oxide was prepared by a modified Hummers’ method and used as support for dispersing of nanoparticles. SrCoO3-δ nanoparticles were prepared and characterized by X-ray diffraction technique. They were used accompanied by Pt nanoparticles on the reduced graphene oxide (RGO) support for preparing of Pt-SrCoO3-δ-RGO catalyst. Transmission electron microscopy images were used to show the morphology and distribution of nanoparticles. The catalytic activity of the prepared catalyst was investigated for METHANOL ELECTROOXIDATION by cyclic voltammetry and electrochemical impedance spectroscopy techniques and compared with the catalytic activity of Pt-RGO catalyst. The effects of some experimental parameters affecting on METHANOL oxidation such as METHANOL concentration, temperature and scan rate were investigated on Pt-SrCoO3-δ-RGO catalyst and the optimum conditions were suggested. Pt-SrCoO3-δ-RGO catalyst showed better catalytic activity for METHANOL oxidation compared with Pt-RGO catalyst indicating that Pt-SrCoO3-δ-RGO can be used as a promising catalyst for application in direct METHANOL fuel cells.

Here, graphene oxide is synthesized and functionalized with methyl viologen and chitosan to be used as a novel catalyst support for Pt nanoparticles. The particle size and distribution of Pt nanoparticles are characterized by transmission electron microscope images. Pt nanoparticles with the mean particle size of 3. 62 nm are dispersed on the support very uniformly. The catalytic activity of the prepared catalyst is investigated for METHANOL oxidation by cyclic voltammetry technique. The prepared catalyst showed very good catalytic activity for METHANOL oxidation. The experimental and statistical analyses are used to investigate the effect of mutual interaction between temperature and METHANOL concentration on anodic current density of METHANOL oxidation. The statistical analysis results reveals that the influence of temperature and METHANOL concentration as main factors and their reciprocal interactions are significant at α =0. 05. Meanwhile, the results confirm that the response increases with both main factors. The enhancement of the anodic current density of METHANOL oxidation with temperature and METHANOL concentration is equal to 530. 22% and 184. 89%, respectively. Therefore, the effect of temperature on the response is higher than that of METHANOL concentration.

In this work, Pt, Fe and Co nanoparticles were prepared by chemical reduction of the metal salts in chitosan as the support. NaBH4 was used as the reducing agent Pt-Fe, Pt-Co and Pt-Fe-Co-chitosan nanocomposites were synthesized and characterized by UV–Vis spectra and Transmission electron microscopy images. GC/Pt-chitosan, GC/Pt-Co-chitosan, GC/ Pt-Fe-chitosan and GC/Pt-Co-Fe-chitosan electrodes were prepared.The performances of these electrodes for METHANOL ELECTROOXIDATION were investigated through cyclic voltammetric and chronoamperometric curves. The effect of some experimental factors such as the amounts of Fe and Co nanoparticles dispersed in chitosan, METHANOL concentration and scan rate were studied and the optimum conditions were determined.The effect of temperature was also investigated and the activation energies were calculated. The performance of Pt-Fe-Co-chitosan nanocomposites was determined in a direct METHANOL fuel cell in different conditions.The electrochemical and fuel cell measurements showed that Pt-Fe-Cochitosan nanocatalyst has the best activity for ELECTROOXIDATION of METHANOL among all different compositions electrodes.

A nanocatalyst coating was prepared at surface of a glassy carbon electrode by electropolymerization of pyrrole by cycling the electrode potential between -0.8 and 0.8 V (vs. Ag/AgCl). Then, polypyrrole film was potentiostatically coated with platinum nanoparticles at constant potential of -0.2 V (vs. Ag/AgCl). The resulting electrode was denoted as GCE/PPy/Pt. This modified electrode was characterized by IR, SEM, TEM and EDX. The electrocatalytic oxidation of ethanol at the GCE/PPy/Pt has been investigated using cyclic voltammetric and chronoamperometric methods. The effects of various parameters on electrocatalytic oxidation of the ethanol, such as the thickness of PPy film, the amount of platinum nanoparticles, ethanol concentration, potential scan rate and working potential limit in anodic direction, were investigated. The kinetic of the ethanol oxidation is discussed on the GCE/PPy/Pt. The stability and reproducibility of this modified electrode were also studied.

In this article, the effect of the electrode surface morphology is investigated in the METHANOL ELECTROOXIDATION process. For this purpose, a Ni-P layer of fine structure and two different Ni-B coatings having granular and cauliflower surface morphologies were plated separately on the graphite electrodes (GEs). The surface structure of samples was investigated by scanning electron microscopy (SEM) and their elemental analysis was done with electrode dispersive energy analysis (EDS). Then these modified electrodes were used as the anode for METHANOL oxidation reaction (MOR) in alkaline solution. Electrochemical studies were accomplished with cyclic voltammetry (CV) and chronoamperometry (CA) methods. Studies have shown, these different structures make a difference in the electrocatalytic performance of the electrodes and the highest METHANOL oxidation efficiency is related to Ni-B electrode with granular morphology. In order to reveal the METHANOL oxidation mechanism, coordination of anodic and cathodic peaks in CV diagrams was studied. Based on the results, we have offered the mechanism proposed by Fleischmann et al.

A two-dimensional, single-phase, isothermal model has been developed for a direct METHANOL fuel cell (DMFC). The model considers the anode and cathode electrochemical equations, continuity, momentum and species transport in the entire fuel cell. Then, the equations are coupled together and solved simultaneously using a commercial, Finite element based, COMSOL Multiphysics software. The crossover of METHANOL is also investigated in the model. This model describes the electrochemical kinetics of METHANOL oxidation at the anode catalyst layer by nonTafel kinetics. The concentration distribution of METHANOL, water, and oxygen was predicted by the model. In addition, the changes of METHANOL crossover and fuel utilization with current density were evaluated for different METHANOL concentrations (0. 5 M, 1 M, 2 M, 4 M, and 6 M). Furthermore, it was also found that the crossover of METHANOL decreases at low METHANOL concentrations and high current densities. The results show that the polarization curve is in agreement with experimental data.