scholarly journals Use of Dendrimers during the Synthesis of Pt-Ru Electrocatalysts for PEM Fuel Cells: Effects on the Physical and Electrochemical Properties

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
J. C. Calderón ◽  
L. Calvillo ◽  
M. J. Lázaro ◽  
E. Pastor
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Pem Fuel Cells ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Stripping ◽  
Ru Nanoparticles ◽  
Treatment Benefits ◽  
Heat Treated ◽  
Direct Methanol

In this work, Pt-Ru catalysts were synthesized by a novel methodology which includes the use as encapsulating molecules of dendrimers of different generation: zero (DN-0), one (DN-1), two (DN-2), and three (DN-3). Synthesized catalysts were heat-treated at 350°C, and the effects of this treatment was established from the physical (X-ray dispersive energy (XDE) and X-ray diffraction (XRD)) and electrochemical characterization (cyclic voltammetry and chronoamperometry). Results showed that the heat-treatment benefits the catalytic properties of synthesized materials in terms of CO and methanol electrochemical oxidation. The curves for CO stripping were more defined for heat-treated catalysts, and methanol oxidation current densities were higher for these materials. These changes are principally explained from the removal of organic residues remaining on the surface of the Pt-Ru nanoparticles after the synthesis procedure. After the activation of the catalysts by heating at 350°C, the real importance of the use of these encapsulating molecules and the effect of the generation of the dendrimer become visible. From these results, it can be concluded that synthesized catalysts are good catalytic anodes for direct methanol fuel cells (DMFCs).

Preparation and Characterization of Pt/Superfine Mesocarbon Microbead Powers Electrocatalysts

2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin
Keyword(s):  
Reduction Method ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Platinum Particles ◽  
Platinum Electrocatalyst ◽  
Direct Methanol

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).

Pt and Ru X-ray Absorption Spectroscopy of PtRu Anode Catalysts in Operating Direct Methanol Fuel Cells

2006 ◽  
Vol 110 (20) ◽  
pp. 9932-9938 ◽  
Author(s):  
Stanislav Stoupin ◽  
Eun-Hyuk Chung ◽  
Soma Chattopadhyay ◽  
Carlo U. Segre ◽  
Eugene S. Smotkin
Keyword(s):  
Fuel Cells ◽  
Absorption Spectroscopy ◽  
Direct Methanol Fuel Cells ◽  
Anode Catalysts ◽  
X Ray ◽  
Direct Methanol ◽  
Methanol Fuel Cells ◽  
X Ray Absorption

Water Balance in PEM and Direct Methanol Fuel Cells

2004 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Michael G. Izenson ◽  
Roger W. Hill
Keyword(s):  
Fuel Cells ◽  
Water Balance ◽  
Power Systems ◽  
Direct Methanol Fuel Cells ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Electrolyte Membrane ◽  
Direct Methanol ◽  
Specific Calculations ◽  
Methanol Fuel Cells

Water management is a critical design issue for polymer electrolyte membrane (PEM) fuel cells, because the PEM must be maintained at the proper water content to remain ionically conducting without flooding the electrodes. Furthermore, portable PEM power systems should operate at water balance to minimize weight. This paper presents the basic design relationships that govern water balance in a PEM fuel cell. Specific calculations are presented based on data from hydrogen/air and direct methanol fuel cells currently under development for portable power systems. We will show how the water balance operating point depends on the cell operating parameters and show the sensitivity to off-design conditions.

PtRu, PtRuFe and PtRuNi alloy electrocatalysts decorated on composite support C-MWCNTs for direct methanol fuel cells

2021 ◽  
Vol 11 (1) ◽  
pp. 94-98
Author(s):  
Quan Dang Long ◽  
An Nguyen Minh ◽  
Vinh Thach Phuc ◽  
Ngan Nguyen Thi Thanh ◽  
Lil Owin Khưu ◽  
...  
Keyword(s):  
Direct Methanol Fuel Cells ◽  
Methanol Oxidation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composite Support ◽  
Transmission Electron ◽  
Direct Methanol ◽  
Co Reduction ◽  
Alloy Catalysts ◽  
Better Than

In this work, carbon Vulcan XC-72 (C) and carbon nanotubes (CNTs) supported ternary platinum-ruthenium-iron (PtRuFe) and platinum-ruthenium-nickel (PtRuNi) alloy nanoparticles have been synthesized by a co-reduction method. The catalyst samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and cyclic voltammetry (CV). The results show that ternary alloy catalysts are always better than binary alloy catalysts. In particular, PtRuNi is the best catalyst for methanol oxidation reaction. 

A Comparative Investigation of the Electrocatalytic Oxidation of Methanol on Pt Modified TiO2 Nanotube Electrodes with Two Methods

2014 ◽  
Vol 521 ◽  
pp. 586-590
Author(s):  
Yong Ping Luo ◽  
Shun Jian Xu ◽  
Zong Hu Xiao ◽  
Yong Huang ◽  
Wei Zhong ◽  
...  
Keyword(s):  
High Performance ◽  
Direct Methanol Fuel Cells ◽  
Comparative Investigation ◽  
Electrolytic Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxidation Of Methanol ◽  
Direct Methanol ◽  
Electro Catalytic Oxidation ◽  
Electro Catalytic Activity

In this work, it was investigated and compared that electro-catalytic oxidation of methanol in acidic medium at TiO2nanotube (TNT) electrode modified by platinum (Pt) with two methods. Pt modified TNT electrodes were prepared by thermal decomposition (TD) and electrolytic deposition (ED). The so-prepared TD-Pt/TNT and ED-Pt/TNT electrodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical investigations indicate that ED-Pt/TNT has higher electro-catalytic activity and better tolerance to poisoning species in methanol oxidation than TD-Pt/TNT, which can be ascribed to the higher dispersion and stability of ED-Pt than TD-Pt on TNT electrode. The present work provides some basis for the design of high performance catalysts for direct methanol fuel cells.

High resolution synchrotron X-ray investigation of carbon dioxide evolution in operating direct methanol fuel cells

2009 ◽  
Vol 11 (8) ◽  
pp. 1559-1562 ◽  
Author(s):  
Christoph Hartnig ◽  
Ingo Manke ◽  
Jana Schloesser ◽  
Philipp Krüger ◽  
Robert Kuhn ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
High Resolution ◽  
Direct Methanol Fuel Cells ◽  
Carbon Dioxide Evolution ◽  
X Ray ◽  
Direct Methanol ◽  
Methanol Fuel Cells

scholarly journals Electrosynthesis and Characterization of Novel CNx-HMMT Supported Pd Nanocomposite Material for Methanol Electro-Oxidation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3578
Author(s):  
Faizah Altaf ◽  
Rohama Gill ◽  
Patrizia Bocchetta ◽  
Rida Batool ◽  
Muhammad Usman Hameed ◽  
...  
Keyword(s):  
Direct Methanol Fuel Cells ◽  
Research Work ◽  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Doped ◽  
Composite Nanomaterial ◽  
Electrochemically Deposited ◽  
Direct Methanol

In the current research work, palladium (Pd) nanoparticles were electrochemically deposited on a nitrogen doped montmorillonite (CNx-MMT) support using the underpotential deposition (UPD) method. The prepared Pd based composite electrode was studied as an electrocatalyst for methanol fuel oxidation. The catalysts and the supporting materials montmorillonite, acid activated montmorillonite, and nitrogen doped montmorillonite (MMT, HMMT and CNx-HMMT) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electrochemical characterization by cyclic voltammetry (CV). The results indicated that Pd supported on CNx-HMMT possesses enhanced electrocatalytic activity and stability compared to commercial Pd/C, which was attributed to its higher electrochemical surface area (ECSA) (23.00 m2 g−1). The results demonstrated the potential application of novel Pd/CNx-HMMT composite nanomaterial as electrocatalysts for methanol electrooxidation in direct methanol fuel cells (DMFCs).

scholarly journals Organic-Inorganic Novel Green Cation Exchange Membranes for Direct Methanol Fuel Cells

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4686
Author(s):  
Marwa H. Gouda ◽  
Tamer M. Tamer ◽  
Abdelaziz H. Konsowa ◽  
Hassan A. Farag ◽  
Mohamed S. Mohy Eldin
Keyword(s):  
Fuel Cells ◽  
Cation Exchange ◽  
Zirconium Phosphate ◽  
Direct Methanol Fuel Cells ◽  
Low Cost ◽  
Methanol Permeability ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Commercializing direct methanol fuel cells (DMFC) demands cost-effective cation exchange membranes. Herein, a polymeric blend is prepared from low-cost and eco-friendly polymers (i.e., iota carrageenan (IC) and polyvinyl alcohol (PVA)). Zirconium phosphate (ZrPO4) was prepared from the impregnation–calcination method and characterized by energy dispersive X-ray analysis (EDX map), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), then incorporated as a bonding and doping agent into the polymer blend with different concentrations. The new fabricated membranes were characterized by SEM, FTIR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and XRD. The results revealed that the membranes’ physicochemical properties (oxidative stability, tensile strength) are enhanced with increasing doping addition, and they realized higher results than Nafion 117 because of increasing numbers of hydrogen bonds fabricated between the polymers and zirconium phosphate. Additionally, the methanol permeability was decreased in the membranes with increasing zirconium phosphate content. The optimum membrane with IC/SPVA/ZrPO4-7.5 provided higher selectivity than Nafion 117. Therefore, it can be an effective cation exchange membrane for DMFCs applications.

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