1215 results about "Methanol fuel" patented technology

The invention concerns a membrane electrode unit (MEU) for electrochemical equipment, especially for membrane fuel cells. The membrane electrode unit has a “semi-coextensive” design and contains an ionically conductive membrane, two catalyst layers, and gas distributor substrates of different sizes on the front and back sides. The first gas distributor substrate has smaller surface dimensions than the ionically conductive membrane, while the second gas distributor substrate has the same area as the ionically conductive membrane. The membrane electrode unit has, because of its special design, a stable structure that can be handled well, and which exhibits advantages for sealing the reactive gases off from each other and in its electrical properties. In particular, the hydrogen penetration current is distinctly reduced. The membrane electrode unit is used in PEM fuel cells, direct methanol fuel cells, electrolyzers, and other electrochemical equipment.

The invention provides lubricating oil for a methanol fuel engine, which comprises the following components in percentage by weight: metal detergent 2.2-5.2, ashless dispersant 3.5-6.8, antioxidant and anticorrosion agent 0.5-1.6, high-temperature antioxidant 0.3-0.8, viscosity index improver 6-11, oiliness solvent 2.8-6, anti-foaming agent 120ppm, metal anti-rust agent 0.3-0.7, base oil 62.7-83, demulsifying agent 0.1-0.3, metal extreme pressure anti-wear agent 1.0-4 and pour point depressant 0.3-0.9. The lubricating oil of the invention has functions of preventing wear and rust of the engine, can prevent the active ingredients thereof from being extracted and emulsified by methanol and is particularly suitable for engines using M85 or M100 methanol gasoline as a fuel.

A compact, lightweight direct methanol fuel cell unit includes a circular membrane electrode assembly (MEA) having a cathode, a proton exchange membrane (PEM), and an anode, an air flow duct on the cathode side of the MEA, an annular fuel reservoir on the anode side of the MEA which contains a mixture of methanol and water as fuel, a carbon dioxide (CO.sub.2) relief valve communicating with the fuel reservoir, and a control unit. Due to the CO.sub.2 release mechanism, the fuel cell is completely self-sustaining without the need for a mechanical auxiliary system. Additionally, the control unit improves the stability of the fuel cell power output and the catalysis activity of the MEA. Another embodiment of the present invention is a direct methanol fuel cell system which incorporates a number of MEAs and a fuel cell reservoir. All the cathodic electrical terminals of the MEAs are serially connected together while they are electronically communicating with the control unit. The anodic electrical terminals similarly communicate electronically with the control unit. Higher power and voltage are thus attained while maintaining a compact size of the fuel cell system.

The invention relates to an island-shaped porous tri-metal nano rod with a gold core/silver-platinum alloy shell structure, which adopts the gold core/silver-platinum alloy shell structure formed by a cylindrical gold nano rod core and an island-shaped porous silver-platinum alloy shell coated on the outer surface of the cylindrical gold nano rod core. The preparation method comprises the following steps of preparation of gold crystal seed solution, preparation and purification of gold nano rod solution, preparation of solution of a platinum coated gold core/platinum shell nano rod, preparation of island-shaped porous tri-metal nano rod with the gold core/silver-platinum alloy shell structure and the like. The tri-metal nano rod has the advantages of stronger ability of catalyzing the methanol oxidation, stronger CO poisoning resistant ability, lower cost and the like, and can be widely used for preparing a methanol fuel battery catalyst; and the preparation method has the advantages of simplicity, low consumption, environmental protection, and high efficiency, and by the method, the island-shaped porous tri-metal nano rod with the gold core/silver-platinum alloy shell structure with high yield and narrow size distribution can be obtained.

A PtNi alloy/graphene combined nanometer catalyst with a hollow structure adopts the graphene as a carrier and loads the PtNi alloy nanometer particles of which the grain diameter is 10-50 nm on the surface of the graphene, wherein the PtNi alloy nanometer particles are hollow spherical structures. The method for preparing the combined catalyst comprises the following steps: dispersing the graphene oxide in water liquor to which surfactant is added through ultrasound; uniformly mixing with soluble nickel salt (II); adding the reducing agent in inert gas atmosphere; adding soluble platinum salt (IV); stirring at 0-50 DEG C to execute the reduction reaction; centrifuging, washing and drying the reaction product to obtain the PtNi alloy/graphene combined nanometer catalyst with the hollow structure. The PtNi alloy/graphene combined nanometer catalyst with the hollow structure in the invention has good electro-catalytic property on electrochemical oxidation of methyl alcohol, and can be widely applied in methyl alcohol fuel cells.

The invention discloses an oxygen reduction catalyst prepared from grapheme modified by a macrocyclic compound, and a preparation method thereof. The grapheme modified by a macrocyclic compound is used as the catalyst and is used for catalyzing the oxygen reduction of batteries under acidic, neutral and alkaline conditions. The catalyst can efficiently reduce oxygen in a solution, the direct 4e process can be realized, the spike potential of the oxygen reduction under alkaline condition can reach 0.1 V (vs. Ag/AgCl), and the stability is high. The catalyst has simple preparation process, low cost and good catalytic activity. The preparation method of the catalyst comprises the following steps of: firstly, conducting ultrasonic dispersion after proportionally mixing grapheme and the macrocyclic compound; then, filtering; and finally, drying to obtain the catalyst. In addition, the catalyst has great anti-poisoning effect on carbon monoxide, methanol, formaldehyde, glucose and the like which can poison a platinum catalyst. The oxygen reduction catalyst can be applied to the fields of proton exchange membrane fuel batteries, direct methanol fuel batteries, metal-air battery cathode materials and the like.

The invention provides preparation of a carbon nanotube material embedded with a quantum-dot modified metal organic framework. The preparation comprises the following steps of firstly, adding a certain amount of powder quantum dots to a formed metal organic framework precursor solvent so that the quantum dots of which the diameters are matched with the sizes of pore passages are embedded into the pore passages of the formed metal organic framework; secondly, uniformly mixing the obtained quantum-dot modified metal organic framework and melamine powder, and performing high-temperature processing to obtain a composite material (QD/UMCM-1@CNT) in a carbon nanotube embedded with the quantum-dot modified metal organic framework; and finally, enabling Pt to be loaded on a surface of the composite material carbon nanotube (Pt/QD/UMCM-1@CNT) by microwave radiation heating to be used as a positive electrode catalyst of a methanol fuel cell. Compared with a traditional hydrothermal method for synthesis of the carbon nanotube, the quantum-dot modified metal organic framework obtained by high-temperature processing is embedded into the composite material in the carbon nanotube, the structural aspects such as the length and the diameter of the carbon nanotube are more consistent, and a catalyst substrate with a unified structure is easier to form.

The invention relates to the following: a method for step-by-step alkylation of primary polymeric amines by step-by-step deprotonation with a metallo-organic base and a subsequent reaction with an alkyl halide; a method for modifying tertiary polymeric amines with other functional groups; polymers with secondary/tertiary amino groups and with quaternary ammonium groups; polymers with secondary/tertiary amino groups and other functional groups, especially cation exchanger groupings; membranes consisting of the above polymers, either non-crosslinked or ionically or covalently cross-linked; acid-base-blends/membranes, and a method for producing same, consisting of basic polymers with polymers containing sulphonic acid, phosphonic acid or carboxyl groups; the use of ion exchanger polymers as membranes in membrane processes, e.g., polymer electrolyte membrane fuel cells, direct methanol fuel cells, redox batteries, or electrodialysis; the use of the inventive hydrophilic polymers as membranes in dialysis and reverse osmosis, nanofiltration, diffusion dialysis, gas permeation, pervaporation and perstraction.

An ion exchange composition membrane is made up of dispersed natural clay and/or organized clay in ion conducting polymeric film as a methanol barrier material. The membrane exhibits low methanol crossover, high proton conductivity and is thus suitable for use in direct methanol fuel cells with low costal advantage.

The invention discloses a high-electric conductivity aromatic polymer ionic liquid diaphragm material and a preparation method thereof. The high-conductivity aromatic polymer ionic liquid diaphragm material comprises an cation and an anion, wherein the cation is a composite cation formed by combining at least one ion of hydrogen ions or metal ions with organic molecules; and the anion is a fluorine-contained sulfonic acid anion or a fluorine-contained sulfimide anion which is connected to an aromatic benzene ring-contained polymer side chain. Compared with the prior art, the polymer ionic liquid diaphragm material of the invention has the advantages of difficult loss of ionic liquid, electric conductivity without depending on water, penetration resistance of OH-anion, methanol or vanadium ions, and the like, can form a stable ion channel which has high ionic activity, high chemical stability, low ion activating energy and easy adsorption of organic polar solvents and is an ideal diaphragm material which can be applied to various fields of lithium ion batteries, secondary lithium ion batteries, methanol fuel batteries, liquid flow batteries, electrodialysis water treatment, atomic energy industry and analysis, catalytic synthesis, chlor-alkali industry, and the like.

The invention discloses a preparation method of PtRu/graphene nano electro-catalyst, comprising the following steps of: ultrasonically dispersing oxidized nano graphite sheets into liquid polylol; then adding a chloroplatinic acid solution and a sodium acetate solution, sufficiently mixing, wherein the content of the oxidized nano graphite sheets contained in a mixture is 0.3-1.1 g/L, the concentration of chloroplatinic acid is 0.0004-0.002 mol/L, the concentration of ruthenium chloride is 0.0004-0.0013 mol/L, and the concentration of sodium acetate is 0.005-0.027 mol/L; transferring the mixture to a microwave hydro-thermal reaction kettle for microwave hydro-thermal reaction for 5-10 minutes; and filtering, washing and drying to obtain the PtRu/graphene nano electro-catalyst, wherein the mass fraction of a PtRu alloy contained in the PtRu/graphene nano electro-catalyst is 20-40 percent, the mass fraction of graphene is 80-60 percent, the atomic ratio of the PtRu alloy is Pt:Ru=1:2-1.5:1, and the liquid polylol is propanetriol or glycol. The preparation method has energy saving, fastness, simple process, and the like; and in addition, the prepared PtRu/graphene nano electro-catalyst has good electrocatalysis property for the oxidation of methanol and ethanol and is widely used as anode catalysts of direct methanol fuel cells.

A gas diffusion cathode for electrochemical cells provides higher power capability through the use of nano-particle catalysts. The catalysts comprise nanometer-sized particles of transition metals such as nickel, cobalt, manganese, iron, palladium, ruthenium, gold, silver, and lead, as well as alloys thereof, and respective oxides. These catalysts can substantially replace or eliminate platinum as a catalyst for oxygen reduction. Cathodes using such catalysts have applications to metal-air batteries, hydrogen fuel cells (PEMFCs), direct methanol fuel cells (DMFCs), direct oxidation fuel cells (DOFCs), and other air breathing electrochemical systems.

The present invention provides a system and method for passive thermal-fluids management in a liquid feed fuel cell. In particular, the present invention provides a system and method for passive thermal-fluids management in a direct methanol fuel cell having a methanol storage medium and a methanol and water mixing medium. The fuel cell may also include a methanol distribution medium that facilitates uniform distribution of methanol to the mixing medium and the anode, wherein the methanol and water are used for fuel by the direct methanol fuel cell.

The invention discloses a Pt-CeO2/graphene electro-catalyst which uses graphene as a carrier, platinum as an active component and CeO2 as an auxiliary component, wherein the mass fraction of the platinum contained in the Pt-CeO2/graphene electro-catalyst is 20 percent; and the mole ratio of the platinum and cerium is 1:1-2.5:1. A preparation method of the Pt-CeO2/graphene electro-catalyst comprises the following steps of: ultrasonically dispersing oxidized nano graphite sheets into glycol; then adding a chloroplatinic acid solution, an aqueous ammonium ceric nitrate solution and an aqueous sodium acetate solution, and sufficiently mixing; transferring a mixture to a microwave hydro-thermal reaction kettle; and after microwave hydro-thermal reaction, filtering, washing and drying to obtain the Pt-CeO2/graphene electro-catalyst. The preparation method has energy saving, fastness, simple process, and the like; and in addition, the prepared Pt-CeO2/graphene electro-catalyst has high electrocatalysis activity for the electrochemical oxidation of methanol and is widely used for direct methanol fuel cells.

The invention discloses a three-dimensional nitrogen-doped graphene platinoid-loaded composite electro-catalyst. A preparation method comprises the following steps of ultrasonically dispersing graphene oxide sheet in an aqueous solution, adding urea and soluble nickel salt for full and uniform mixing, transferring the mixture into a hydrothermal reaction kettle for reaction, performing freeze-drying to obtain three-dimensional nitrogen-doped graphene, dissolving the three-dimensional nitrogen-doped graphene in ethylene glycol, sequentially adding chloroplatinic acid, copper chloride dehydrate and glutamic acid, and performing microwave reaction to obtain the catalyst. The method has the characteristics of that energy is saved, the speed is high, and the operation is simple; the raw materials are easy to obtain, the yield is high, the capability of platinum in the direct electro-catalytic oxidation of methanol under an acidic condition can be remarkably improved, peak current is 3 to 4 times than that of a commercial carbon black platinum-loaded electro-catalyst and a commercial carbon black platinum-ruthenium-loaded electro-catalyst, and the prepared catalyst is widely applied to a methanol fuel cell.

The present invention provides a method for manufacture of supported noble metal based alloy catalysts with a high degree of alloying and a small crystallite size. The method is based on the use of polyol solvents as reaction medium and comprises of a two-step reduction process in the presence of a support material. In the first step, the first metal (M1=transition metal; e.g. Co, Cr, Ru) is activated by increasing the reaction temperature to 80 to 160° C. In the second step, the second metal (M2=noble metal; e.g. Pt, Pd, Au and mixtures thereof) is added and the slurry is heated to the boiling point of the polyol solvent in a range of 160 to 300° C. Due to this two-step method, an uniform reduction occurs, resulting in noble metal based catalysts with a high degree of alloying and a small crystallite size of less than 3 nm. Due to the high degree of alloying, the lattice constants are lowered. The catalysts manufactured according to the method are used as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC), direct-methanol fuel cells (DMFC) or as gas phase catalysts for CO oxidation or exhaust gas purification.

The invention relates to a preparation method of the membrane electrode of a direct methanol fuel cell. The method comprises the following steps: an electrostatic spinning technology is adopted to construct a nano-fiber network structure thin membrane mixed by active carbon powder and Nafion resin; a precious metal nano-catalyst is deposited on the surface of the manufactured nano-fiber network structure thin membrane, so that a cathode catalyst layer thin membrane and an anode catalyst layer thin membrane are manufactured respectively; or the mixture of the precious metal nano-catalyst and the Nafion resin is taken as raw materials to directly construct the cathode catalyst layer thin membrane and the anode catalyst layer thin membrane through the electrostatic spinning technology; a cathode gas diffusion layer, the anode catalyst layer thin membrane, a Nafion membrane, the cathode catalyst layer thin membrane and a cathode gas diffusion layer are hot-pressed finally, so that the aggregation of the membrane electrode of the direct methanol fuel cell is manufactured; the membrane electrode with a nano-fiber three-dimensional network structure is constructed through the electrostatic spinning technology, so that the maximization of the three-phase reaction interface of the membrane electrode is achieved, and the improvement of electrocatalytic activity, mass-transfer efficiency and utilization efficiency of the catalyst is achieved.

A process for preparing catalyst coated membranes and membrane electrode assemblies for use in direct methanol fuel cells is provided. Cathode and anode layers are formed by spraying catalyst-containing inks onto a novel framed electrolytic membrane to form a catalyst coated membrane. The spraying process optionally employs one or more masks, which carefully control where the catalyst-containing ink is deposited. Following application of the cathode and anode layers, diffusion layers are prepared and inserted onto the catalyst coated membranes, and pressed to form membrane electrode assemblies.

A direct methanol fuel cell unit is provided with a fuel cell including an anode, a cathode with a hydrophobic microporous layer, an electrolyte membrane put in-between, and a fuel supply path supplying fuel to the anode. The fuel supply path is provided with an upwind water barrier preventing back-diffusion of water and a gas flow path channeling gas generated at the anode and disposed between the barrier and the anode. A water-rich zone is formed between the water barrier and the cathode microporous layer. Water loss from either side of this zone is eliminated or minimized, thereby permitting direct use of highly concentrated methanol in the fuel flow path with good fuel efficiency and power performance. The cell unit can be applied equally well to both an active circulating air cathode and an air-breathing cathode.

The invention relates to a carbon-supported CoN fuel-cell catalyst as well as a preparation method and application thereof. The catalyst comprises the following components in mass percentage: 40-99 percent of carbon material and 1-60 percent of active component. The catalyst is prepared through the following steps of: dispersing the components into a mortar loaded with a solvent, fully grinding until the solvent is completely volatilized, and obtaining a catalyst precursor after vacuum drying; and roasting for 2-4 hours by increasing the temperature for 200-900 DEG C at the speed of 20 DEG C/minute under the protection of an inert-gas atmosphere. The catalyst is applied to alkaline fuel cells, direct methanol fuel cells, direct ethanol fuel cells or low-temperature fuel cells. The catalyst is a non-platinum catalyst, so that the cost of the fuel cells can be markedly lowered; and the preparation method disclosed by the invention is simple and easy to operate, has low cost, is suitable for industrialized production and has good application prospects.

A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion® PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5–5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O₂ and H₂ gas permeability, while retaining proton conductivities similar to Nafion®. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

Passive water management techniques are provided in an air-breathing direct oxidation fuel cell system. A highly hydrophobic component with sub-micrometer wide pores is laminated to the catalyzed membrane electrolyte on the cathode side. This component blocks liquid water from traveling out of the cathode and instead causes the water to be driven through the polymer membrane electrolyte to the cell anode. The air-breathing direct oxidation fuel cell also includes a layer of cathode backing and additional cathode filter components on an exterior aspect of the cell cathode which lessen the water vapor escape rate from the cell cathode. The combination of the well laminated hydrophobic microporous layer, the thicker backing and the added filter layer, together defines a cathode structure of unique water management capacity, that enables to operate a DMFC with direct, controlled rate supply of neat (100%) methanol, without the need for any external supply or pumping of water. The cell anode is provided with a hydrophilic backing layer. When the water is driven through the polymer membrane electrolyte from the cell cathode to the cell anode chamber, it is available for the anodic reaction, and any excess water is carried out along CO₂ ventilation channels to the outside environment.

Existing catalysts are noble metals generally, which are costly and easy poisoning. Active component of the disclosed catalyst is transition metal nitride. Carrier is activated carbon powder Vulcan XC-72. Percentage content of mass of transition metal nitride in active component is 1-6%. The preparation method includes steps: dissolving macrocyclic compound of transition metal, Vulcan XC-72 into organic solvent, and carrying out ultrasonic action for 30-60 minutes; stirring up and drying out the said solution under normal temperature, and obtaining powder after drying; loading the powder to closed container and letting ammonia into the container; controlling temperature of heat treatment at 600-1000 deg.C, and time as 0.5-10h so as to obtain the catalyst after natural cooling. Area ratio activity of carbon carried platinum catalyst is 1.5mA/cm2, and the disclosed carbon carried nitride catalyst reaches to 3.1 mA/cm2. Features are: simple flow and easy controlled procedure.