Presentation of anodic electrocatalyst for polymeric fuel cell: Pt nanoparticles immobilized on NdFeO3 nanocrystals and carbon nanotubes (original) (raw)
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Journal of Nanostructures, 2020
In this work, NdFeO3 nanoparticles were synthesized through a simple co-precipitation method. The formation of NdFeO3 particles was verified by X-ray powder diffraction, infrared spectroscopy, vibrating sample magnetometer, and transmission electron microscopy analysis. Polyaniline and chitosan were employed as proper support for production of metal nanoparticles. Novel Pt-NFO/PA-CH nanocomposite was fabricated by immobilization of Pt nanoparticles on the PA-CH support in the presence of NdFeO3 nanoparticles. The prepared nanocomposite was characterized by transmission electron microscopy and X-ray powder diffraction analysis. The catalytic performance of the Pt-NFO/PA-CH nanocomposite was evaluated for electro-oxidation of methanol through CO stripping voltammetry, cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Durability of the Pt-NFO/PA-CH catalyst was investigated and the effects of several factors such as temperature, scan rate, and methanol ...
2016
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...
High-Performance Electrocatalytic Activity of Pt Nanoparticles/Chitosan 3-D Nanocomposites
A novel kind of hybrid nanocomposites containing Pt nanoparticles (PtNPs) and Chitosan (CS) have been fabricated based on the PtNPs inserting into the porous structure of CS on the surface of glassy carbon electrode (GCE). Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectra and several electrochemical techniques, such as cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS), have been used to characterize PtNPs/CS modified electrode. Electrocatalytic experiments show that these uniform nanocomposites can greatly decrease the over-potential and increase the peak current in the methanol oxidation and oxygen reduction. In comparison with the results reported previously, the PtNPs-CS nanocomposites have excellent electrocatalytic activity towards the oxidation of methanol and reduction of oxygen, which can be utilized to develop new fuel cell with high performance.
International Journal of Hydrogen Energy, 2017
Platinum e cobalt (PtCo) alloy based highly efficient nano electro-catalysts on reduced graphene oxide (rGO) matrix have been synthesized for the electro-oxidation of methanol, by chemical reduction method. Different molar ratio of Pt (IV) and Co (II) ions along with graphene oxide (GO) were reduced using ethylene glycol to obtain PtCo nanoparticles onto rGO sheets (Pt/rGO, PtCo (1:1)/rGO, PtCo (1:5)/rGO, PtCo (1:9)/rGO and PtCo (1:11)/rGO) with 20 wt. % metal and 80 wt. % rGO. The average particle size of PtCo nanoparticles onto rGO support was observed to be 2e5 nm using XRD and TEM analysis. The PtCo (1:9)/rGO nanocomposite catalyst exhibited~23 times higher anodic current density compare to commercially available Pt/C catalyst (1.68 mA/cm 2) for methanol oxidation reaction. The peak power density of 118.4 mW/cm 2 was obtained for PtCo (1:9)/rGO catalyst in direct methanol fuel cell (DMFC) at 100 C, 1 bar, and 2 M methanol as anode feed, which is~3 times higher than that of Pt/C catalyst. The results indicate the potential application of synthesized nanocomposite catalyst in commercial DMFCs.
Journal of Applied Electrochemistry, 2009
This work tries to study the problem of methanol crossover through the polymer electrolyte in direct methanol fuel cells (DMFCs) by developing new cathode electrocatalysts. For this purpose, a series of gas diffusion electrodes (GDEs) were prepared by using single-walled carbon nanotubes (SWCNTs) supported Pt-Pd (Pt-Pd/ SWCNT) with different Pd contents at the fixed metal loading of 50 wt%, as bimetallic electrocatalysts, in the catalyst layer. Pt-Pd/SWCNT was prepared by depositing the Pt and Pd nanoparticles on a SWCNTs support. The elemental compositions of bimetallic catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES) system. The performances of the GDEs in the methanol oxidation reaction (MOR) and in the oxygen reduction reaction with/without the effect of methanol oxidation reaction were investigated by means of electrochemical techniques: cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The results indicated that GDEs with Pt-Pd/SWCNT possess excellent electrocatalytic properties for oxygen reduction reaction in the presence of methanol, which can originate from the presence of Pd atoms and from the composition effect.
International Journal of Hydrogen Energy, 2011
Direct methanol fuel cell a b s t r a c t In the present work, a detailed characterization of the electrochemical behavior of carbon supported PdePt electrocatalysts toward CO and methanol electrooxidation in direct methanol fuel cells is reported. Technical electrodes containing an ionomer in their catalyst layer were prepared for this purpose. CO and methanol electrooxidation reactions were used as test reactions to compare the electrocatalytic behavior of bimetallic supported nanoparticles in acidic liquid electrolyte and in solid polymer electrolyte (real fuel cell operating conditions). Experimental results in both environments are consistent and show that the electrochemical behavior of carbon supported PdePt depends on their composition, giving the best performance in direct methanol single fuel cell with a Pd:Pt atomic ratio of 25:75 in the catalyst.
Multifunctional catalysts toward methanol oxidation in direct methanol fuel cell
Journal of Applied Electrochemistry, 2015
In the current study, a nanoscale perovskite SrFeO 3 (SrFNPs) was synthesized by a rapid microwave-assisted co-precipitation method and characterized by X-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy, Energy dispersive X-ray, and vibrating sample magnetometer techniques. Modified glassy carbon electrode with Pt nanoparticles (PtNPs), functionalized carbon nanotubes (CNTs), and SrFNPs as multifunctional catalyst is prepared and its catalytic activity toward methanol oxidation is investigated. Based on the electrochemical studies, a PtNPs-CNTs-SrFNPs nanocomposite was shown a considerable activity for methanol oxidation in comparison of PtNPs, PtNPs-CNTs, and PtNPs-SrFNPs. A direct methanol fuel cell was designed, assembled, and tested with suggested PtNPs-CNTs-SrFNPs nanocomposites under several different conditions. The effect of some experimental factors such as temperature, methanol concentration, and flow rate as well as NaOH concentration on electrical performances of fuel cell were studied and optimized.
Journal of Power Sources, 2008
Preparation and characterization of a platinum (Pt)-based catalyst using a redox polymer, poly(vinylferrocenium) (PVF +), as the support material was described. Pt was obtained from aqueous solution of K 2 PtCl 4 in the complex form. Pt particles were reduced by chemical and electrochemical means. Chemical reduction was performed using aqueous hydrazine solution and electrochemical reduction was carried out in H 2 SO 4 solution. The Pt/PVF + catalyst system showed catalytic activity towards methanol oxidation. Cyclic voltammetry was used for the electrochemical characterization of the catalyst system. Scanning electron microscopy (SEM) images and energy dispersive X-ray spectrum (EDS) of the catalyst system were also recorded. The system was tested in a single fuel cell configuration at ambient temperature and atmospheric pressure. The open circuit voltage (OCV) was 680 mV for the system and the maximum power density was 0.31 mW cm −2 at a current density of 0.63 mA cm −2. Catalytic activity of Pt/PVF + system towards methanol oxidation was comparable with the related catalysts in the literature.
Journal of Electroanalytical Chemistry, 2012
One of the key objectives in fuel cell technology is to reduce Pt loading by the improvement of its catalytic activity towards alcohol oxidation. Here, a sol-gel based method was used to prepare ternary and quaternary carbon supported nanoparticles by combining PtARu with Mo, Ta, Pb, Rh or Ir, which were used as electro-catalysts for the methanol and ethanol oxidation reactions in acid medium. Structural characterization performed by XRD measurements revealed that crystalline structures with crystallites ranging from 2.8 to 4.1 nm in size and with different alloy degrees were produced. Tantalum and lead deposited as a heterogeneous mixture of oxides with different valences resulting in materials with complex structures. The catalysts activities were evaluated by cyclic voltammetry and by Tafel plots and the results showed that the activity towards methanol oxidation was highly dependent of the alloy degree, while for ethanol the presence of a metal capable to promote the break of CAC bond, such as Rh, was necessary for a good performance. Additionally, the catalysts containing of TaO x or PbO x resulted in the best materials due to different effects: the bi-functional mechanism promoted by TaO x and a better dispersion of the catalysts constituents promoted by PbO x .