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Showing papers on "Direct methanol fuel cell published in 2020"


Journal ArticleDOI
TL;DR: This study presents a review of both external and internal components used in active systems, including the fuel and product management utilized in active DMFC, and summarizes the challenges and future advances in the design of active system DMFC.

125 citations


Journal ArticleDOI
TL;DR: In this paper, the activity and stability of a non-precious metal catalyst of type Fe-N-C in acidic media is reported. But the performance of this catalyst was not evaluated in a Direct Methanol Fuel Cell (DMFC).
Abstract: In this work a comprehensive study of the activity and stability of a non-precious metal catalyst of type Fe- N- C in acidic media is reported. The catalyst was prepared from polyaniline, dicyandiamide and iron acetate as precursors. Temperature-dependent rotating-disk electrode experiments were performed to determine the activation energy of the catalyst. Besides, load cycle durability tests with and without the addition of methanol show that there is no additional deactivation caused by methanol addition. In a Direct Methanol Fuel Cell (DMFCs) our catalyst performed similarly good in comparison to other Fe-N-C catalysts. Raman and Mossbauer spectroscopy provide valuable information on the structural composition and chemical changes induced by durability and stability testing of the catalyst. While the maximum power density during DMFC operation decreases by 85%, the qualitative distribution of iron sites might indicate the formation of iron and iron oxide clusters as decomposition product associated with the disintegration of FeN4 sites.

110 citations


Journal ArticleDOI
TL;DR: In this article, a 1-dimensional isothermal model for a direct methanol fuel cell (DMFC) is presented, which accounts for the kinetics of the multi-step methanoline oxidation reaction at the anode.
Abstract: A one dimensional (1-D), isothermal model for a direct methanol fuel cell (DMFC) is presented. This model accounts for the kinetics of the multi-step methanol oxidation reaction at the anode. Diffusion and crossover of methanol are modeled and the mixed potential of the oxygen cathode due to methanol crossover is included. Kinetic and diffusional parameters are estimated by comparing the model to data from a 25 cm2 DMFC. This semi-analytical model can be solved rapidly so that it is suitable for inclusion in real-time system level DMFC simulations.

104 citations


Journal ArticleDOI
TL;DR: It is shown that a four-coordinated nickel atom is able to form charge-transfer orbitals through delocalization of electrons near the Fermi energy level and offers a gateway towards the development of high performance and durable non-platinum direct methanol fuel cell.
Abstract: Achieving a functional and durable non-platinum group metal-based methanol oxidation catalyst is critical for a cost-effective direct methanol fuel cell. While Ni(OH)2 has been widely studied as methanol oxidation catalyst, the initial process of oxidizing Ni(OH)2 to NiOOH requires a high potential of 1.35 V vs. RHE. Such potential would be impractical since the theoretical potential of the cathodic oxygen reduction reaction is at 1.23 V. Here we show that a four-coordinated nickel atom is able to form charge-transfer orbitals through delocalization of electrons near the Fermi energy level. As such, our previously reported periodically arranged four-six-coordinated nickel hydroxide nanoribbon structure (NR-Ni(OH)2) is able to show remarkable methanol oxidation activity with an onset potential of 0.55 V vs. RHE and suggests the operability in direct methanol fuel cell configuration. Thus, this strategy offers a gateway towards the development of high performance and durable non-platinum direct methanol fuel cell. Development of suitable methanol oxidation reaction catalysts for direct methanol fuel cells is challenging due to sluggish kinetics. Herein, authors show that four-coordinate nickel atoms form charge-transfer orbitals near the Fermi energy level, leading to remarkable methanol oxidation activity.

94 citations


Journal ArticleDOI
Lei Qian1, Shuli Luo1, Lisha Wu1, Xiaorong Hu1, Wen Chen1, Xin Wang1 
TL;DR: In this paper, a hierarchical hollow porous self-supported flexible NF/Co3O4/NiCo2O4 electrode was used for methanol electrocatalytic oxidation.

78 citations


Journal ArticleDOI
TL;DR: In this paper, the role of Ir content and its bi-functional mechanism on kinetics of methanol oxidation reaction (MOR) was studied and the optimized composition of Pt2Ir/MWCNT exhibits efficient METH oxidation and could be a potential catalyst for direct methanoline fuel cells.

61 citations


Journal ArticleDOI
TL;DR: A novel bimetallic nickel oxide/copper oxide metal–organic framework (NiO/CuO MOF) has been developed by using two linkers: Benzene Dicarboxylic acid (BDC) and Pyrazine to develop a promising catalytic material for electrolysis of methanol in direct meethanol fuel cell (DMFC).
Abstract: In this work a novel bimetallic nickel oxide/copper oxide metal-organic framework (NiO/CuO MOF) has been developed by using two linkers: Benzene Dicarboxylic acid (BDC) and Pyrazine. The composites of NiO/CuO MOF with different amounts of reduced graphene oxide (rGO) were synthesized through a hydrothermal method and subsequently characterized by multiple significant techniques like XRD, SEM, EDX, FTIR and Raman IR for an investigation of their structural and morphological properties. The prepared series of material was later employed for electrochemical oxidation of methanol, tested by cyclic voltammetry (CV) in basic medium on a modified glassy carbon electrode (GCE). The electrochemical response depicts that increasing concentration of rGO enhances the electrocatalytic activity of the catalyst for methanol oxidation reaction (MOR). The catalyzed oxidation reaction of methanol by NiO/CuO MOF and rGO-NiO/CuO MOF composites give a superlative current density of 437. 28 mA/cm2 at 0.9 V potential at 50 mV/s scan rate. This activity makes it a promising catalytic material for electrolysis of methanol in direct methanol fuel cell (DMFC).

48 citations


Journal ArticleDOI
TL;DR: In this article, standalone cobalt dendrites are prepared then doped with graphene flakes by a simple electroplating technique, which results in a significant increase in the current density.
Abstract: In this work, standalone cobalt dendrites are prepared then doped with graphene flakes by a simple electroplating technique. Microstructural examination using SEM with EDX, as well as Raman spectroscopy measurements, verified the successful formation of graphene. The prepared material exhibit a favorably high electrochemical methanol oxidation activity with an onset oxidation potential of 0.07 V vs. Ag/AgCl, which is significantly lower than that of the Ni (0.35 V vs. Ag/AgCl). The doping process causes a decrease in the ohmic resistance of the material from 3.2 Ohm cm−2 to 2 Ohm cm−2, which consequently resulted in a significant increase in the current density from 35 mA cm−2 to 62 mA cm−2 using 1 M methanol at 0.5 V vs. Ag/AgCl. After two hours of current discharge at 0.5 V vs. Ag/AgCl, the catalyst doped with graphene showed a current density of 62 mA cm−2. This is an eight-times higher than that obtained in the case of the Ni nano-powder. An electrode prepared by depositing the catalyst on the surface of a highly conductive porous Ni foam was successfully used as the anode of a passive air cathode direct methanol fuel cell, demonstrating an open circuit voltage of 0.75 V using 0.25 M methanol in 1 M KOH.

47 citations


Journal ArticleDOI
25 Feb 2020
TL;DR: This paper summarizes the work on the development of PEMs with various structures and architecture that can affect the membrane’s performance, in terms of microstructures and morphologies, for potential applications in DMFCs.
Abstract: Membrane morphology plays a great role in determining the performance of polymer electrolyte membranes (PEMs), especially for direct methanol fuel cell (DMFC) applications. Membrane morphology can be divided into two types, which are dense and porous structures. Membrane fabrication methods have different configurations, including dense, thin and thick, layered, sandwiched and pore-filling membranes. All these types of membranes possess the same densely packed structural morphology, which limits the transportation of protons, even at a low methanol crossover. This paper summarizes our work on the development of PEMs with various structures and architecture that can affect the membrane’s performance, in terms of microstructures and morphologies, for potential applications in DMFCs. An understanding of the transport behavior of protons and methanol within the pores’ limits could give some perspective in the delivery of new porous electrolyte membranes for DMFC applications.

45 citations


Journal ArticleDOI
TL;DR: In this article, a cross-linked sulfonated poly (ether ether ketone) (C-SPEEK) membranes for direct methanol fuel cell (DMFC) applications are prepared using SPEEK with chloromethyl side groups (SPEEK-Cl) and poly (2,5-benzimidazole)-grafted graphene oxide (ABPBI-GO) as a crosslinker.

45 citations


Journal ArticleDOI
TL;DR: In this paper, a passive single-cell direct methanol fuel cell (DMFC) was designed and fabricated to investigate and compare the performance of three discrete membrane electrode assemblies (MEA) with carbon black (CB), CNT, and N-CNT as the catalyst support, respectively.

Journal ArticleDOI
TL;DR: In this paper, a novel polyion nanocomposite membrane was synthesized by doping the surface and matrix of sulfonated polyethersulfone (SPES) with polyaniline (PANi) nanoparticles to facilitate proton conduction in direct methanol fuel cell (DMFC) application.

Journal ArticleDOI
15 Oct 2020-Energy
TL;DR: In this article, the effect of surface morphology, structure, permeability of diffusion layers (PTFE-treated carbon paper (CP) or carbon cloth (CC)) on the catalyst utilization, methanol, water fluxes, Faraday efficiency, and current discharge in pDMFCs were investigated in liquid and vapor feed pDMfcs.

Journal ArticleDOI
J. Ren1, J. Zhang1, C. Yang1, Ying Yang1, Y. Zhang1, F. Yang1, R. Ma1, Lu Yang1, Haiyan He1, Huajie Huang1 
TL;DR: In this paper, the Pd nanocrystal-decorated three-dimensional (3D) hybrid architectures constructed from nitrogen-doped graphene and low-defect carbon nanotube (Pd/NG-LCNT) through a facile and cost-effective bottom-up method.

Journal ArticleDOI
01 Dec 2020
TL;DR: In this article, a novel proton conductive filler, sulfonated α-zirconium phosphate (ZrP-SO3H), was synthesized and introduced to SPAE to fabricate advanced nanocomposite membranes.
Abstract: Sulfonated poly(aryl ether) (SPAE) membranes have attracted significant attention as polymer electrolyte membranes due to their superior mechanical properties and low cost. However, the poor chemical stability and methanol barrier property of SPAE membranes limit the fuel cell performance. It is necessary to improve the proton conductivity, methanol barrier property, and stability of SPAE for high-performance fuel cells. Herein, a novel proton conductive filler, sulfonated α-zirconium phosphate (ZrP-SO3H), was synthesized and introduced to sulfonated poly(fluorenyl ether ketone) (SPFEK) to fabricate advanced nanocomposite membranes. The oxidative stability, methanol permeability, water uptake, and proton conductivity of the as-prepared nanocomposite membranes were characterized. The nanocomposite membranes exhibited comparable performance as Nafion® 117 membrane in H2/O2 fuel cell and higher performance than Nafion® 117 in direct methanol fuel cell. These results suggest that ZrP-SO3H-doped SPFEK membrane is a promising candidate as a proton exchange membrane in high-performance fuel cells.

Journal ArticleDOI
TL;DR: In this paper, high performing and cost effective nanocomposite membranes for DMFC application are synthesized by incorporating hygroscopic layered double hydroxides (LDH) particles into sulfonated polysulfone (sPSU).

Journal ArticleDOI
01 Nov 2020-Fuel
TL;DR: In this paper, a facile two-step wet chemical approach was adopted to fabricate a novel polydiphenylamine (PDPA)/SiO2 nanosphericals decorated reduced graphene (GR) nanosheets composite material based modified fluorine-doped tin oxide electrode (FTO/GR-PDPA-SiO 2) for the efficient electro-oxidation of methanol.

Journal ArticleDOI
TL;DR: In this study, a carbon-encapsulated Pt cathode catalyst was synthesized by heat treatment of Pt-aniline complex coated carbon nanofibers and showed higher performance and stability in single cell tests under various conditions compared to commercial Pt/C.
Abstract: Methanol crossover is one of the largest problems in direct methanol fuel cells (DMFCs). Methanol passing from the anode to the cathode through the membrane is oxidized at the cathode, degrading th...

Journal ArticleDOI
TL;DR: In this paper, a combination of bimetallic PtRu and MXene was used to enhance the direct methanol fuel cell (DMFC) electrocatalyst performance using response surface methodology (RSM).

Journal ArticleDOI
TL;DR: NiSe/RGO nanoparticles were used for methanol oxidation reaction (MOR) using pyrolyzation and selenylation to obtain high performance and low cost catalysts for energy storage, conversion and practical applications.

Journal ArticleDOI
TL;DR: Fe-N-C catalysts obtained from zeolitic imidazolate framework-8 with a tunable size ranging from 30 to 400 nm are precisely synthesized, giving new inspiration for the development of rational design strategies of non-precious metal catalysts.
Abstract: Comprehension of the structure-activity relationship is of great importance for the rational design of electrocatalysts for the oxygen reduction reaction (ORR). Herein, Fe-N-C catalysts obtained from zeolitic imidazolate framework-8 (ZIF-8) with a tunable size ranging from 30 to 400 nm are precisely synthesized. Structural investigation indicates that the catalyst with smaller size possesses a higher proportion of mesopores originating from particle stacking, which leads to enhanced catalyst utilization and accelerated mass transport. The size effect of the catalyst on ORR activity is systematically investigated by rotation disk electrode (RDE) and direct methanol fuel cell (DMFC) tests. The electrochemical performance of the Fe-N-C catalyst is found to be increased with the reduction of its particle size. The correlation among size, mesoporosity and catalyst performance is discussed, giving new inspiration for the development of rational design strategies of non-precious metal catalysts.

Journal ArticleDOI
TL;DR: In this article, sulfonated polyethersulfone (sPES)-SPEEK membranes were used for direct methanol fuel cell (DMFC) applications, achieving a power density of about 130mW cm−2 at 80°C in 4M methanoline solution.

Journal ArticleDOI
TL;DR: In this paper, PEMFC and direct methanol fuel can be used as catalysts for O2 reduction reaction, but they suffer from low stability in acid medium in proton exchange membrane fuel cells (PEMFC).
Abstract: PGM-free catalysts have high initial activity for O2 reduction reaction, but they suffer from low stability in acid medium in proton exchange membrane fuel cells (PEMFC) and direct methanol fuel ce...

Journal ArticleDOI
TL;DR: In this paper, the catalytic efficacy and improved mass activity of morphologically engineered metal-free graphitic carbon nitride towards methanol oxidation were explored for the first time in literature.

Journal ArticleDOI
TL;DR: In this article, the sulfonated boron nitride (SBN) based SPEEK composite membranes were synthesized for direct methanol fuel cell (DMFC) application.


Journal ArticleDOI
01 Dec 2020
TL;DR: In this paper, a sulfonated poly(fluorenyl ether ketone) (SPFEK)/α-zirconium phosphate (ZrP) nanocomposite membrane containing 2.0 wt.
Abstract: Methanol crossover through polymer electrolyte membranes (PEMs) is a major concern in fuel cell research. In order to address this problem, a sulfonated poly(fluorenyl ether ketone) (SPFEK)/α-zirconium phosphate (ZrP) nanocomposite membrane containing 2.0 wt. % of ZrP nanosheets was prepared by casting a dimethylacetamide (DMAc) dispersion containing SPFEK and exfoliated ZrP nanosheets. The membrane was characterized and tested as a PEM in a single direct methanol fuel cell (DMFC) at 80 °C. The introduction of ZrP nanosheets improved the oxidative stability and reduced methanol permeability and water uptake of the PEM. The SPFEK/ZrP nanocomposite membrane led to the best cell performance among the single cells using SPFEK/ZrP nanocomposite membrane, SPFEK, and Nafion® 117. The maximum power densities obtained for the cells composed of the above three membranes were 51.3, 41.4, and 43.6 mW/cm2, respectively.

Journal ArticleDOI
TL;DR: In this article, the authors designed and fabricated optimized and efficient proton transport channels in PEMs by introducing sulfonated poly (ether sulfone) nanofiber with amino-modified SiO2 protuberance structures.


Journal ArticleDOI
TL;DR: In this paper, three-dimensional graphene frameworks are adopted to construct cathode MPL for the first time, whose intrinsic pore structure and characteristics contribute to an enhanced water management, and the performance and stability of the as-prepared DMFC are significantly improved.