Showing papers on "Direct methanol fuel cell published in 2008"
TL;DR: A series of cross-linked quaternized poly(vinyl alcohol) (PVA) membranes have been prepared and characterized for alkaline direct methanol fuel cell (DMFC) applications as mentioned in this paper.
244 citations
TL;DR: In this paper, a series of Pt-CeO 2 /C catalysts with various compositions of ceria were synthesized by wet impregnation method and the physicochemical characterizations of the catalysts were carried out by using Brunauer Emmett Teller (BET) surface area and pore size distribution (PSD) measurements, X-ray diffraction (XRD), XPS and transmission electron microscopy (TEM) techniques.
Abstract: In order to develop a cheaper and durable catalyst for methanol electrooxidation reaction, ceria (CeO 2 ) as a co-catalytic material with Pt on carbon was investigated with an aim of replacing Ru in PtRu/C which is considered as prominent anode catalyst till date. A series of Pt-CeO 2 /C catalysts with various compositions of ceria, viz. 40 wt% Pt-3–12 wt% CeO 2 /C and PtRu/C were synthesized by wet impregnation method. Electrocatalytic activities of these catalysts for methanol oxidation were examined by cyclic voltammetry and chronoamperometry techniques and it is found that 40 wt% Pt-9 wt% CeO 2 /C catalyst exhibited a better activity and stability than did the unmodified Pt/C catalyst. Hence, we explore the possibility of employing Pt-CeO 2 as an electrocatalyst for methanol oxidation. The physicochemical characterizations of the catalysts were carried out by using Brunauer Emmett Teller (BET) surface area and pore size distribution (PSD) measurements, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques. A tentative mechanism is proposed for a possible role of ceria as a co-catalyst in Pt/C system for methanol electrooxidation.
194 citations
TL;DR: In this paper, the anode reaction in direct methanol fuel cells using a database of adsorption free energies for 16 intermediates on 12 close-packed transition metal surfaces calculated with periodic, selfconsistent, density functional theory (DFT-GGA).
168 citations
TL;DR: In this article, an anion exchange membrane for alkaline direct methanol fuel cell (ADMFC) was prepared by doping polybenzimidazole (PBI) membrane with KOH.
137 citations
TL;DR: In this article, the PtRu nanoparticles of ca. 2.3 nm on carbon mesoporous materials (PtRuCMMs) were synthesized directly using SBA-15 mesoporic silica as the template, furfuryl alcohol and trimethylbenzene as the primary carbon source, and platinum and ruthenium acetylacetonates as the co-feeding metal and carbon precursors.
Abstract: Well-dispersed, highly stable PtRu nanoparticles of ca. 2–3 nm on carbon mesoporous materials (PtRuCMMs) were synthesized directly using SBA-15 mesoporous silica as the template, furfuryl alcohol and trimethylbenzene as the primary carbon source, and platinum and ruthenium acetylacetonates as the cofeeding metal and carbon precursors. Results obtained from X-ray diffraction and X-ray photoelectron spectroscopy show that the Pt metal in the PtRu-CMMs was present in the form of a face-centered cubic (fcc) crystalline structure and the alloyed PtRu nanoparticles were composed mainly of Ru oxides, Ru(0), and Pt(0) metals. Further studies by X-ray absorption spectroscopy confirmed that a highly alloyed state of the PtRu nanoparticles is responsible for the superior electrocatalytic performance observed for the PtRu-CMMs, as compared to typical commercial electrocatalysts. The Pt50Ru50-CMM sample was found to possess the best electrocatalytic performance and long-term durability and should appeal to direct methanol fuel cell applications as anodic electrodecatalyst.
129 citations
TL;DR: In this article, a series of hydroxyl-conducting anion exchange membranes were prepared by blending chloroacetylated poly(2,6-dimethyl-1,4-phenylene oxide) (CPPO) with bromomethylated polymer(BPPO), and their fuel cell-related performances were evaluated.
127 citations
TL;DR: In this article, the anode and cathode electrodes of direct methanol fuel cells (DMFC) have been fabricated using Pt-Ru/MWNT and 1:1 Pt / MWNT + Pt / C electrocatalyst, respectively.
121 citations
TL;DR: In this article, a direct methanol fuel cell (DMFC) operating with hydroxide ion conducting membranes was reported, which achieved a power density of 16mW cm −2, at 60°C using oxygen.
120 citations
TL;DR: In this paper, 3A, 4A, 5A, 13X, mordenite, and HZSM-5 were incorporated into chitosan (CS) matrix to fabricate the hybrid membranes for direct methanol fuel cell (DMFC).
115 citations
TL;DR: In this paper, a composite membrane consisting of polyvinylidene fluoride (PVdF) and Nafion has been prepared by impregnating various amounts of Nafions into the pores of electrospun PVdF and characterized by scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and proton conductivity measurements.
111 citations
TL;DR: In this article, Nafion composite proton exchange membranes are prepared using mesoporous MCM-41 silica nanospheres as inorganic fillers, and the composite membrane containing I wt.% of fillers displays the best cell performance in direct methanol fuel cell tests.
TL;DR: In testing, the proposed design for a microfuel cell as an on-chip power source was able to generate electric power on methanol without pumps under both neutral and acidic conditions.
Abstract: This paper proposes a novel design for a microfuel cell as an on-chip power source and demonstrates its fabrication and operation to prove the concept. Its simple design is important from the viewpoints of fabrication (e.g., replication), integration, and compatibility with other microdevices. In testing, the prototype cell was able to generate electric power (maximum: ca. 1.4 μW) on methanol without pumps under both neutral and acidic conditions. As for the size, the electrode part of the cell (two cathodes and one anode) is 400 μm in width and 6 mm in length. The evaluation demonstrated that the proposed design is a promising on-chip power source for miniature devices.
TL;DR: Developed PEMs were extensively characterized by studying their physicochemical and electrochemical properties under DMFC operating conditions and showed high stabilities and proton conductivity and low methanol permeability.
Abstract: Chitosan was modified into N-p-carboxy benzyl chitosan (NCBC) by introducing an aromatic ring grafted with carboxylic acid as the proton conducting group. A preparation procedure of highly conductive and stable organic−inorganic nanostructured NCBC−silica−poly(vinyl alcohol) (PVA), proton exchange membrane (PEM) for direct methanol fuel cell (DMFC), by the sol−gel method in aqueous media has been reported. These PEMs were developed by cross-linking and designed to consist of weak proton conducting (−COOH) groups at organic segments and strong proton conducting (−SO3H) groups at inorganic segments to achieve high charge density and stabilities. Cross-linking density and NCBC−silica content in the membrane matrix were systematically optimized to control their nanostructure, thermal, mechanical, and chemical stabilities, as well as proton and fuel transport properties. Developed PEMs were extensively characterized by studying their physicochemical and electrochemical properties under DMFC operating condition...
TL;DR: In this article, the effect of the particle size of the OMC supports on their performance for the oxygen reduction reaction (ORR) in direct methanol fuel cells was investigated.
TL;DR: In this paper, as-prepared Pd Co bimetallic nanoparticles showed a single-phase face-centered-cubic disordered structure, and the mean particle size is found to decrease with increase in Co content.
TL;DR: In this paper, the optimal molar ratio of TiO 2 /Pt was found at 1:2 for the catalysts without heat treatment and was at 1 :1 for catalysts by heat treatment at 500°C.
TL;DR: In this paper, Zeolite beta particles with different sizes and narrow size distribution were hydrothermally synthesized and incorporated into chitosan (CS) matrix to prepare CS/zeolite β hybrid membranes for direct methanol fuel cell (DMFC).
TL;DR: In this paper, a mesoporous thin film carbon (TFC) material, of short channels vertical to the film, was synthesized by the replication of meso-silica SBA-15(⊥) template and was deposited with PtRu nanocatalyst as an anodic material in direct methanol fuel cell (DMFC).
Abstract: Ordered mesoporous thin film carbon (TFC) material, of short channels vertical to the film, was synthesized by the replication of mesoporous silica SBA-15(⊥) template and was deposited with PtRu nanocatalyst as an anodic material in direct methanol fuel cell (DMFC). The anode nanocatalyst PtRu was characterized by XRD, Raman, XPS, nitrogen adsorption, and COad stripping. Electrocatalytic activity, characterized by anodic current, was compared with PtRu supported on various carbon supports, including TFC, CMK-3, and XC-72. The much enhanced methanol electrochemical oxidation activity in PtRu/TFC was ascribed to increased nanocatalysts' utilization efficiency with the short nanochannels of TFC.
01 Jan 2008
TL;DR: A fuel cell is an electrochemical device that continuously and directly converts the chemical energy of externally supplied fuel and oxidant to electrical energy as mentioned in this paper, and is customarily classified according to the electrolyte employed.
Abstract: A fuel cell is an electrochemical device that continuously and directly converts the chemical energy of externally supplied fuel and oxidant to electrical energy. Fuel cells are customarily classified according to the electrolyte employed. The five most common technologies are polymer electrolyte membrane fuel cells (PEM fuel cells or PEMFCs), alkaline fuel cells (AFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs) and solid oxide fuel cells (SOFCs). However, the popularity of PEMFCs, a relatively new type of fuel cell, is rapidly outpacing that of the others.
TL;DR: In this article, the physico-chemical properties of solid superacid nanoparticles were investigated by TGA, X-ray diffraction (XRD), and transmission electron microscopy (TEM).
TL;DR: A series of new covalent organic/inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for direct methanol fuel cell (DMFC) applications is prepared through the following sequence: (i) copolymerization of impregnated styrene (St), p -vinylbenzyl chloride (VBC) and divinylbenzene (DVB).
TL;DR: In this paper, a passive direct methanol fuel cell (DMFC) stack that consists of six unit cells was designed, fabricated, and tested, and it was found that the stack performance increased when the methanoline concentration inside the fuel tank was increased from 2.0 to 6.0 mM.
TL;DR: In this paper, the authors present the synthesis of platinum nanoparticles (Pt NPs) and their subsequent deposition on the nitrogen-doped carbon nanotubes, which have been directly grown on a carbon cloth (CNT-CC electrode).
TL;DR: In this paper, the support effect of carbon nanotubes (CNTs) for direct methanol fuel cell (DMFC) was studied using CNTs with and without defect preparation, carbon black, and fishbone-type CNT.
TL;DR: In this article, polyoxometalate anion PMo 12 O 40 3− (POM) is chemically impregnated into a Pt-supported carbon nanotubes (Pt/CNTs) catalyst that is prepared via a colloidal method.
TL;DR: In this article, a high-temperature vapor-fed direct methanol fuel cell (DMFC) has been implemented using H3PO4-doped polybenzimidazole (PBI) as the electrolyte.
Abstract: A high-temperature vapor-fed direct methanol fuel cell (DMFC) has been implemented using H3PO4-doped polybenzimidazole (PBI) as the electrolyte. The influence of the cell temperature, the methanol concentration, and the oxygen partial pressure has been studied. This investigation included the evaluation of the cell performance, each electrode potential, and crossover current. A lifetime test for 10 days was intermittently carried out to assess the stability of the cell response. Increases in the temperature notably enhanced the performance of the cell, although the methanol crossover also increased. The methanol concentration was found to have an optimum value, because a low amount of methanol led to mass-transfer limitations and a large amount promoted the crossover and limited the availability of water for methanol oxidation. An increase in the oxygen partial pressure markedly improved the cell response. The higher comburent availability and reduced methanol crossover effect explain this behavior. The s...
TL;DR: In this article, the effects of introducing sub-μm porous PTFE film and ZrP particles into Nafion membranes on the performance of methanol fuel cell (DMFC) performance were investigated.
TL;DR: In this article, two types of Pd-Co films were electrodeposited onto Au substrates by applying different current density (−10 or −200 ǫ cm −2 ); and then characterized them in terms of morphology, composition, crystal structure, and catalytic activity.
TL;DR: In this article, the impact of structural parameters and operating conditions has not been researched yet for vapor-fed operation of a DMFC at near-ambient conditions, but a detailed parameter study that included reference cell measurements to assess anode and cathode losses separately was performed.
TL;DR: In this paper, a modified sulfonated poly(ether ether ketone) (SPEEK) membrane was attempted by blending with a charged surface modifying macromolecule (cSMM) for direct methanol fuel cell (DMFC) application.