1080 results about "Cathode catalyst" patented technology

The object of the present invention is to provide fuel cell including a cell that is formed by sandwiching solid polymer membrane between an anode and a cathode that generates electricity with stability and high performance by evenly moistening the solid polymer membrane. For this purpose, in a gas diffusion layer 24, which is positioned adjacent to a cathode catalyst layer 22, the content of fluororesin in an area on the side of the entrance for the oxidizer is set to be higher than in another area on the side of the exit so that the water repellency in the entrance side area is higher than in the exit side area. As a result, a water permeation suppressing part 24A, where the water permeability is relatively low, is formed in the area on the entrance side, while a water permeable part 24B, where the water permeability is relatively high, is formed in the area on the exit side.

The invention is a hydrogen passivation shut down system for a fuel cell power plant (10). An anode flow path (24) is in fluid communication with an anode catalyst (14) for directing hydrogen fuel to flow adjacent to the anode catalyst (14), and a cathode flow path (38) is in fluid communication with a cathode catalyst (16) for directing an oxidant to flow adjacent to the cathode catalyst (16) of a fuel cell (12). Hydrogen fuel is permitted to transfer between the anode flow path (24) and the cathode flow path (38). A hydrogen reservoir (66) is secured in fluid communication with the anode flow path (24) for receiving and storing hydrogen during fuel cell (12) operation, and for releasing the hydrogen into fuel cell (12) whenever the fuel cell (12) is shut down.

The invention is a fuel cell (20) having a corrosion resistant and protected cathode catalyst layer (24). The cathode catalyst layer (24) includes a platinum oxygen reduction catalyst and an oxygen evolution catalyst selected from the group consisting of catalysts that are more active than platinum for oxygen evolution. The oxygen evolution catalyst may be uniformly applied within the cathode catalyst layer, or non-uniformly applied to identified high corrosion areas (82) (84) of the cathode catalyst layer (24). The cathode catalyst layer (24) may include heat-treated carbon support material, and/or a heat-treated carbon black within a diffusion layer (40) supporting the cathode catalyst layer (24). The fuel cell (20) may also include an anode catalyst layer (22) having a poor oxygen reduction catalyst having a greater oxygen reduction over potential than platinum.

A method for making a carbon-metal-nitrogen oxygen reducing cathode catalyst, the method comprising mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate; adding a nitrogen precursor compound to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor; and pyrolyzing the carbon-metal-nitrogen precursor in a closed vessel, thereby forming an oxygen reducing cathode catalyst. The carbon-metal-nitrogen catalyst requires no precious metal such as Pt, and also provides benefits such as controlled deposition of catalytically active nitrogenous compounds that can increase the catalytic activity of the catalyst when compared to gaseous deposition of nitrogen to the surface of the carbon support.

The invention discloses a core-shell structure catalyst for fuel cells and its pulse electrodeposition preparation method. The active component of the catalyst is a nanoparticle with a core-shell structure, and an active metal is cladded in the form of an ultrathin shell on the surface of a carbon carrier loaded metal or alloy nanoparticle serving as a core. The catalyst takes a non-platinum noble metal or transition metal as the core, and adopts more than one of Pt, Ir or Au as the shell. The preparation method includes: preparation of the nanoparticle serving as the core, making of a working electrode for pulse electrodeposition, and preparation of the catalyst by pulse electrodeposition. The catalyst can be used as an anode or cathode catalyst of a low temperature fuel cell. The obtained catalyst has very high stability. Compared with underpotential deposition, the method is simple to operate, has no need for inert atmosphere protection, and is more suitable for large-scale industrial production, also can greatly reduce the noble metal consumption of fuel cells, and greatly reduce the cost of fuel cells, thus having great significance in promoting the commercialization process of fuel cells.

The invention discloses a compound type fuel cell cathode catalyst NGPC/NCNTs and a preparation method thereof, belongs to the technical field of catalyst preparation and aims to develop a cheap and efficient non-precious metal catalyst to solve the problem of high cost of a fuel cell cathode catalyst made of a Pt-based material. An MOF (metal-organic framework) material as a C source of the NGPC/NCNTs is pre-carbonized at a low temperature firstly, a graphitization catalyst and a N source are introduced step by step, two times of corresponding high-temperature heat treatment are performed, and the NGPC/NCNTs are prepared. The active component of the NGPC/NCNTs is N-doped graphitized porous C or CNTs, a pore structure is in a micropore-mesopore compound type, and a continuous conduction framework in three-dimensional space is formed through structural connection of dispersed porous C particles by the CNTs, so that the NGPC/NCNTs have good conductivity and higher mass transfer rate and can show efficient catalytic activity, methyl alcohol tolerance and cycle stability, which are better than those of a commercial Pt/C electrocatalyst, in an alkaline medium.

The invention discloses application of manganese dioxide for preparing a cathode of a microorganism fuel battery. The method comprises the following steps: the manganese dioxide is taken as a catalyst, the mixture of the catalyst, a conductive carbon material and a caking agent is coated on a conductive substrate to prepare the cathode of the microorganism fuel battery and a membrane composite cathode applied to the microorganism fuel battery. Compared with a non-catalytic electrode, MnO2 is taken as a cathode catalyst for remarkably increasing the reducing speed, reducing the polarization of the cathode and improving the energy output of the microorganism fuel battery; compared with the prior Pt catalyst, MnO2 has low price and wide source, and the microorganism fuel battery assembled by the catalyst of the cathode can operate stably for a long time and has high power output. The manganese dioxide for preparing the microorganism fuel battery electrode provides solid foundation for the commercial application of the microorganism fuel battery.

An electrochemical device converts carbon dioxide to a reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each has reactant introduced thereto. A polymer electrolyte membrane is interposed between the anode and the cathode. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm², measured as the area of the cathode gas diffusion layer that is covered by catalyst, and CO selectivity is at least 50% at a cell potential of 3.0 V. In some embodiments, the polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

A fuel cell includes a cathode catalyst layer, an anode catalyst layer, a proton-conductive membrane provided between the cathode catalyst layer and the anode catalyst layer, and a fuel transmitting layer that supplies a vaporized component of a liquid fuel to the anode catalyst layer. Water generated in the cathode catalyst layer is supplied to the anode catalyst layer via the proton-conductive membrane. The liquid fuel is one of a methanol aqueous solution having a concentration of over 50% by molar and liquid methanol.

The invention relates to a solid oxide fuel battery cathode material and a preparation method thereof. The chemical formula of the material is MxA(1-x)M`yB(1-y)O(3-Delta). The material is prepared by adopting an EDTA-citrate combination and complexation method or a glycine combustion method. The cathode material can be smeared onto the electrolyte surface by screen printing, spraying, dip coating or flow casting, and then calcined at high temperatures to obtain a cathode catalyst layer. The catalyst layer is in the working state, that is, the negative current passes through the electrode, so that the precious metal oxides can obtain electrons to take the reduction reaction, emerge out of the lattice of the perovskite or perovskite-like ceramic material to enrich on the surface of the material and to form the precious metal-ceramic composite cathode. The precious metals can be re-oxidized and enter the ceramic oxide lattice when the positive current passes through the electrode.

A membrane electrode assembly includes an electrolyte membrane, anode catalyst layers, and cathode catalyst layers provided counter to the anode catalyst layers, respectively. An insulating layer is provided on the electrolyte membrane between adjacent anode catalyst layers. An insulating layer is provided on the electrolyte membrane between adjacent cathode catalyst layers. The resistivity of the insulating layer is preferably identical to or higher than that of the electrolyte membrane.

The invention discloses a self-humidification membrane electrode for a proton exchange membrane fuel cell and a preparation method thereof. The preparation method comprises the following steps of 1, pre-treating a proton exchange membrane, 2, mixing a carbon-supported platinum or platinum-ruthenium catalyst, a perfluorinated sulfonic acid resin, a hydrophilic organic polymer and an inorganic oxide and in water or a low-boiling point solvent, carrying out ultrasonic treatment to obtain catalyst slurry, and carrying out spray-coating of the catalyst slurry on one side of the proton exchange membrane by an illumination direct-coating technology to obtain an anode catalyst layer, 3, carrying out spray-coating of slurry without the hydrophilic organic polymer and the inorganic oxide on the other side of the proton exchange membrane to obtain a cathode catalyst layer, and 4, carrying out lamination of a gas diffusion layer and the proton exchange membrane of which the two sides are coated with the catalyst layers to obtain the self-humidification membrane electrode. The anode catalyst layer contains the hydrophilic organic polymer and the inorganic oxide so that the self-humidification membrane electrode has excellent self-humidification performances at a high cell temperature and low humidity.

The invention discloses a production method of a high stability CoSe2 / graphene composite electrode material. The method comprises the steps: (1), synthesis of graphene oxide; (2) preparation of a cobalt hydroxide and graphene oxide mixed sol; (3) constant temperature vacuum aging; and (4) preparation of a CoSe2 / graphene composite electrode material. The present invention has the advantages of: (1), according to the above preparation method, CoSe2 is uniformly loaded on the graphene surface to achieve synthesis of a high stability CoSe2 / graphene composite electrode material; (2) the synthesis process is simple and easy to operate, and has mild conditions and low cost of raw materials; (3) compared with the existing non-noble metal electrode material, the CoSe2 / graphene composite electrode material prepared by the present invention has high efficiency electro-catalytic activity; and (4), the CoSe2 / graphene composite electrode material prepared by the present invention has good crystallinity, high stability and strong resistance to poison. The high stability CoSe2 / graphene composite electrode material can be used as a cathode catalyst for a polymer electrolyte membrane (PEMFC) fuel cell, has significantly increased catalytic activity in acid medium, reduces catalyst costs, and significantly enhances battery performance.

The invention belongs to the technical field of a nanomaterial, and specifically relates to an iron-nitrogen-doped graphene porous material with dual-site catalytic oxygen reduction activity, and a preparation method and an application therefor. The porous material is formed by embedding graphite-carbon-coated iron carbide into a nitrogen-doped porous graphene band network structure; the preparation method for the iron-nitrogen-doped graphene porous material comprises the steps of preparing a graphene oxide solution; adding a proper amount of conductive macromolecular pyrrole to the graphene oxide solution; obtaining uniform hydrogel through a hydrothermal process; performing oxidative polymerization on the hydrogel by ferric iron; then dispersing the hydrogel into a fresh ferric iron solution to complete adsorption; then performing drying and high-temperature carbonization thermal processing; and finally removing non-active and free iron phase from the reaction system by dilute acid so as to obtain the iron-nitrogen-doped graphene porous material. The porous material can be used as the negative electrode catalyst for a fuel cell, and shows quite high catalytic oxygen reduction activity, so that the porous material has quite important research meaning and bright application prospects.

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.

The present invention relates to a fuel-cell system. This system includes an anode electrode; a cathode electrode; a separator positioned between the anode electrode and the cathode electrode, wherein the separator is not an ion exchange membrane; an anode catalyst; and a cathode catalyst, wherein the cathode catalyst is a non-precious metal catalyst or metal-free catalyst. The present invention also relates to a method of generating energy from crude fuel. This method involves providing a fuel-cell system and contacting the fuel-cell system with a crude fuel under conditions effective to generate energy from the crude fuel.

The invention discloses a nitrogen-doped Fe/Fe3C/C microbial fuel cell cathode catalyst material and a preparation method thereof, and relates to a microbial fuel cell cathode catalyst material and a preparation method thereof, which aim to solve the problem that the cost is high due to a platinum-carbon catalyst adopted as the microbial fuel cell cathode catalyst material in the prior art. The nitrogen-doped Fe/Fe3C/C microbial fuel cell cathode catalyst material is a composite material prepared from a ferrum source and a carbon source, and is a composite material with Fe particles and Fe3C particles uniformly distributed on a graphitization carbon framework, and the particle diameter is 10nm-300nm. The method comprises the following steps of dissolving, water bath heating, drying, and high-temperature carbonization reduction, thereby obtaining the nitrogen-doped Fe/Fe3C/C microbial fuel cell cathode catalyst material. The preparation method is used for preparing the nitrogen-doped Fe/Fe3C/C microbial fuel cell cathode catalyst material.

Alkaline membrane fuel cells designed with silver cathode catalysts include a catalyst layer comprising silver metal nano-particles and an anion-conducting ionomer. The silver nano-particles are mixed with a solution of the ionomer to form a catalyst ink that is applied to an alkaline membrane to form an ultra-thin cathode catalyst layer on the membrane surface.