238 results about "Electro catalyst" patented technology

The invention discloses a preparation method of a catalyst with a core-shell structure for a low-temperature fuel cell, belonging to the technical field of fuel cells. In the catalyst with the core-shell structure prepared with the preparation method, platinum is taken as a shell, a metal alloy consisting of more than one of metals including ruthenium, platinum, iron, cobalt, nickel, copper, tin, iridium, gold and silver is taken as an inner core, and the shell and the inner core are loaded on a carbon carrier. The preparation method comprises the following preparation steps of: reducing a metal chloride or a metal nitrate with a reducing agent, and forming a core on the carbon carrier with a large specific surface area; stabilizing the core; and precipitating Pt on a core layer with a impregnation reduction method, a high-pressure organic sol method, a microwave method or an electrodeposition process to form the catalyst with the core-shell structure. Due to the adoption of the preparation method, the utilization ratio of noble metal platinum is increased, the cost of an electro-catalyst is reduced effectively, and the methanol oxidizing capability and oxygen reducing activity of the obtained catalyst are increased by 10.8 times and 8.7 times in maximum respectively in comparison to the mass ratio and activity of a commercial JM4100Pt/C catalyst.

A precursor electro-catalyst composition for producing a fuel cell electrode. The precursor composition comprises (a) a molecular metal precursor dissolved or dispersed in a liquid medium and (b) a polymer dissolved or dispersed in the liquid medium, wherein the polymer is both ion-conductive and electron-conductive with an electronic conductivity no less than 10⁻⁴ S/cm (preferably greater than 10⁻² S/cm) and ionic conductivity no less than 10⁻⁵ S/cm (preferably greater than 10⁻³ S/cm). Also disclosed is an electro-catalyst composition derived from this precursor composition, wherein the molecular metal precursor is converted by heat and/or energy beam to form nanometer-scaled catalyst particles and the polymer forms a matrix that is in physical contact with the catalyst particles, coated on the catalyst particles, and/or surrounding the catalyst particles as a dispersing matrix with the catalyst particles dispersed therein when the liquid is removed. The fuel cell comprising such a composition in an electrode exhibits a superior power output.

The invention belongs to the field of carbon materials and electrochemistry, and discloses a heteroatom-doped porous graphite electro-catalyst and preparation and application thereof as well as a device. The method comprises the following steps: firstly adding concentrated HNO3 into a graphite oxide aqueous solution, performing sealing, ultrasonic reaction and stewing, and pouring the solution into deionized water for centrifugation, filtering and drying to obtain graphite oxide with holes in the surface; uniformly mixing the graphite oxide with holes in the surface, a heteroatom-doped source compound and a solvent to obtain a mixture, coating the surface of a substrate with the mixture, and performing freeze drying to obtain a solid thin film; putting the substrate loaded with the solid thin film into a plasma high-temperature tubular reactor for reaction to obtain the heteroatom-doped porous graphite electro-catalyst. The prepared electro-catalyst is higher in oxygen reduction electro-catalytic performance and is higher in electrochemical performance when applied in an electrode material; the electro-catalyst can be applied to the field of proton exchange membrane fuel batteries, direct alcohol fuel batteries and metal-air battery anode materials.

The invention discloses a preparation method for an iron-nitrogen co-doped porous carbon sphere material. The preparation method comprises the following steps: by taking 2-aminopyridine as a monomer and taking ammonium persulfate and ferric chloride as oxidants, performing in-situ polymerization reaction in a duct of a porous silicon dioxide template to obtain a precursor; performing high-temperature carbonization treatment on the precursor in a tubular furnace and an inert gas nitrogen-gas environment; and removing the silicon dioxide template by hydrofluoric acid to obtain the iron-nitrogen co-doped porous carbon sphere material which is taken as an electric catalyst to achieve good catalytic effect in oxygen gas reduction reaction. The preparation method has the advantages that the process is simple and easy to perform and the raw materials are cheap. The prepared carbon material contains a three-dimensional communicated pore structure, has a high specific surface area and a large pore volume, can effectively improve the electric catalytic activity through the heteroatom nitrogen-iron doping, has relatively high electric catalytic efficiency while being applied as a low-price electric catalyst, and has an important value and significance in the fields of doped type porous carbon material preparation and proton membrane fuel battery electric catalysis.

The invention discloses a controllable preparation method of an alpha-manganese dioxide nanowire. The alpha-manganese dioxide nanowire can be directly synthesized by using a hydrothermal method, or the alpha-manganese dioxide nanowire of which the diameter is 10-75nm and the length is 0.1-1mu m can be prepared through controllable thermal treatment within the temperature range of 150-750 DEG C. By adopting the controllable preparation method, no acid reducing agent is needed, the experiment equipment is simple in requirement and high in controllability, and the diameter and the length of the prepared alpha-manganese dioxide nanowire can be controlled. The alpha-manganese dioxide nanowire prepared by using the method can be used as an electrode material of a super capacitor and an ionic battery, an electric catalyst of a lithium-air battery, a water oxidation catalyst for energy storage, and an adsorption material and a denitration catalytic material for environment protection.

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 high-performance ultrathin nitride electro-catalyst with functions of producing hydrogen and oxygen by means of electrochemically totally decomposing water, a method for synthesizing the high-performance ultrathin nitrite electro-catalyst and application thereof. A chemical formula of the high-performance ultrathin nitride electro-catalyst is (Fe<X>Ni<1-X>)<4>N, and the x is larger than 0 and is smaller than 1. The nitrite electro-catalyst is of an ultrathin nanometer plate structure, the size of the nitrite electro-catalyst is 50-100nm, and the thickness of the nitrite electro-catalyst is 1.5-3nm. The method includes synthesizing NiFe hydrotalcite precursors at first; nitriding the NiFe hydrotalcite precursors at high temperatures under the protection of ammonia gas to obtain end products. The high-performance ultrathin nitride electro-catalyst, the method and the application have the advantages that series of nitrite have large specific surface areas, are good in electron conductance and are excellent in performance during electro-catalytic water total-decomposition reaction, limiting currents are higher than limiting currents of Pt/C during electro-catalytic hydrogen evolution reaction (HER), and the performance of the nitride in various aspects are superior to the performance of corresponding oxide NiFe-MMO during oxygen evolution reaction (OER); the electro-catalyst is low in cost, easy and convenient to operate, simple in process and excellent in catalytic performance, and fundamental application research on materials in the field of electro-catalysis can be provided.

The invention provides a method for preparing a graphene-loaded nano alloy catalyst, which is characterized by sequentially comprising the following steps of: 1, oxidizing and stripping graphite to obtain GO (Graphene Oxide); 2, carrying out surface functionalization on the GO by cationic polyelectrolyte; 3, carrying out static assembly on binary metal ions because the surface of the functionalized GO the surface is provided with positive charges; and 4, carrying out in-situ reduction on the bounded metal ions and simultaneously reducing the GO into graphene to obtain high dispersion graphene-loaded nano alloy particles which can be directly used as an electro-catalyst of a methanol fuel cell. By the method, the problems that graphene is aggregated and is difficult to disperse, metal atoms are preferably nucleated and grow at the defect positions on the surface of graphene to cause low particle dispersion degree and two metal ions have different reduction speeds to cause inhomogenous alloy components are solved.

The invention provides a graphene/carbon nano tube/carbon nanofiber electrocatalyst and a preparation method thereof. The electrocatalyst is prepared with the method comprising steps as follows: (1), spinning solution preparation: transition metal salt, a carbon nanofiber precursor polymer and a solvent are mixed uniformly, and a homogeneous spinning solution is obtained; (2), electrospinning: the homogeneous spinning solution is used for electrospinning, fibril felt is obtained; (3), pre-oxidation: the fibril felt is pre-oxidized in an air atmosphere, and pre-oxidized fiber felt is obtained; (4), pyrolysis: the pre-oxidized fiber felt is mixed uniformly with a graphite-phase carbon nitride precursor and graphite-phase carbon nitride and pyrolyzed in an inert atmosphere, and the graphene/carbon nano tube/carbon nanofiber electrocatalyst is obtained. The electrocatalyst has high electrical conductivity, many favorable active sites, good oxygen reduction electrocatalysis performance and better electrocatalysis performance, can be widely applied to the fields of super capacitors, cathode catalysis of fuel cells and the like; the preparation method is simple and large-scale production can be realized.

The invention provides a method for preparing a carbon-supported nano Pt-M fuel cell catalyst. The method comprises the following steps of: (1) dissolving H2PtCl6.6H2O and an M compound with alcohol respectively, combining the dissolved H2PtCl6.6H2O and M compound and ultrasonically processing the mixture for 10 to 20 minutes at the temperature of between 25 and 60 DEG C; (2) performing dry-dipping on a Pt-M active precursor prepared in the step (1) on a carbon support and dehydrating the carbon support with microwave to a constant weight; (3) adding water into the carbon support obtained by the step (2) for pasting and adding a reducing agent into the carbon support for reduction; and (4) filtering, washing and dehydrating the obtained product with microwave to obtain a Pt-M/C catalyst. The nano Pt-M binary alloy fuel cell catalyst prepared by the method of the invention solves the problems of difficult control over graininess and dispersion degree, high platinum load, low adsorption rate, agglomeration and the like existing in the conventional method for preparing an electro-catalyst and has the advantages of simple process, environmental friendliness, relatively low cost, high anti-CO poisoning capacity, high dispersion degree, small grain size, high catalytic performance and the like.

The invention relates to an electrochemical method for synthesizing acidic hydrogen peroxide. According to the electrochemical method, hydrogen, oxygen and an acidic solution serve as raw materials, and an acidic hydrogen peroxide aqueous solution is prepared in an in-situ electro-catalytic mode through a fuel battery type reactor. In the fuel battery type reactor, the oxygen and the hydrogen enter a negative pole and a positive pole through gas inlets of a negative pole end plate and a positive pole end plate correspondingly and conduct an electrochemical reaction on a gas diffusion pole carrying an electro-catalyst, obtained products enter an electrolyte rapidly, and thus the hydrogen peroxide is easily enriched; a proton exchange film is arranged in the middle, so that the explosion risk of direct reaction of the hydrogen and the oxygen is avoided, safety is high, the reactor is small in size, and the products can be simply separated from reactants. By adopting the gas diffusion pole carrying the electro-catalyst, the three-phase reaction interface is effectively increased, the utilization rate of the catalyst is increased, the reaction rate is increased, and the overpotential and energy consumption of the reaction are effectively reduced.

A surface treatment method for improving electro-catalysis hydrogen production performance comprises the steps of 1, preparing a precursor with the hydrothermal growth method; 2, preparing phosphorous nanosheets or nanowires by means of the precursor prepared in the step 1; 3, conducting CV scan round by means of a three-electrode system with the nanosheets or nanowires obtained in the step 2 as a working electrode, a saturated Ag/AgCl electrode as a reference electrode and a platinum sheet as a counter electrode, wherein the surface roughness and surface active sites of the phosphorous nanosheets or nanowires are both increased after scanning. The method has the advantages that by taking Ni2P nanosheets, CoP nanowires, NiCoP nanowires and other transition metal phosphides as the working electrode, the preparing method is simple and environmentally friendly, morphology is easy to control, preparation materials are abundant, and cost is low; after CV scan round is conducted with the transition metal phosphides as the working electrode, electro-catalysis hydrogen production performance is improved greatly, and electro-catalysis performance is excellent; besides, an electro-catalyst material capable of replacing a noble metal catalyst is obtained.

The invention discloses a noble metal-titanium dioxide nano fiber complex and a preparation method and application thereof. The method comprises the following steps of: 1) mixing solution of titanate and solution of polyvinyl pyrrolidone uniformly to form electrostatic spinning stock solution, performing electrostatic spinning to obtain TiO2 nano fibers, and calcining the TiO2 nano fibers to obtain anatase TiO2 nano fibers; and 2) dispersing the anatase TiO2 nano fibers into alcohol, adding noble metal salt solution, mixing the solution uniformly, and performing intermittent microwave heatingto obtain the noble metal-titanium dioxide nano fiber complex. The noble metal-titanium dioxide nano fiber complex provided by the invention has small granule diameter (5 nanometers) and narrow granule distribution, the granules are dispersed high and aggregated, the noble metal content can be randomly controlled from 5 to 60 percent, and the complex has high electric catalytic activity and can be used as an electric catalyst for a fuel cell oxide electrode.

The invention belongs to the technical field of lithium-sulfur batteries, and relates to a diaphragm with an electro-catalysis function and a preparation method and application thereof. The diaphragmis composed of a commercial polymer diaphragm matrix and an electrocatalytic function modification layer coating the surface of one side of the diaphragm matrix, the electrocatalytic function modification layer comprises a binder, a conductive agent and an electrocatalyst; the electrocatalyst is a three-dimensional porous compound composed of graphene and heteroatom doped MoS2. The three-dimensional porous structure constructed by the graphene can adsorb a large amount of lithium polysulfide dissolved in the electrolyte through physical action; the heteroatom-doped MoS2 has rich interface defects, polarity and electrocatalytic activity, can efficiently and chemically adsorb lithium polysulfide and catalyze electrochemical conversion of the lithium polysulfide, inhibits the shuttle effect of the lithium-sulfur battery, and improves the reversible capacity and the cycling stability of the high-sulfur-loading lithium-sulfur battery.

The invention relates to a preparation method of a highly dispersed molybdenum carbide/carbon composite electro-catalyst by adopting an oxidation, reduction and fixation method. The preparation method comprises the following steps that 1, reducing organic matter and ammonium heptamolybdate are dissolved in water to prepare a mixed solution, wherein the mass ratio of the reducing organic matter to the ammonium heptamolybdate is 1: (0.1-2); 2, the mixed solution is subjected to hydrothermal treatment at the temperature of 120-200 DEG C for 4-24 hours, solid is separated out, and washing and drying are performed; 3, the dried solid is calcined in a protective atmosphere at the temperature of 600-1000 DEG C for 2-10 hours to obtain the highly dispersed molybdenum carbide/carbon composite electro-catalyst. The used raw materials are safe, non-toxic, simple to obtain and convenient to prepare and can be synthesized into molybdenum carbide nanomaterials in a large-scale mode.

The invention relates to a preparation and application of a NiWP electric catalyst material with a three-dimensional structure, which belongs to the technical field of clean energy materials. The preparation comprises the following steps: preprocessing foam metal (cathode matrix material) and a pure nickel sheet (anode material) to remove oxides and impurities on the surface; respectively adding a nickel salt and tungsten salt into distilled water according to a ratio, uniformly dissolving in a magnetic stirrer, adding a complexing agent, stirring and dissolving the complexing agent in a tungsten salt-containing solution, mixing the two solutions, then adding a phosphorus salt, uniformly stirring, and finally adjusting a pH value of plating solution by utilizing sulfuric acid and ammonia water; and performing the electric precipitation under a given current density and temperature by adopting a direct-current voltage stabilizing power supply, after a given time of precipitation, cleaning the surface of a test sample by utilizing deionized water, and drying at a room temperature to obtain the NiWP electric catalyst with the three-dimensional structure. The electric catalyst prepared by using the method can effectively reduce overpotential of water electrolysis hydrogen evolution reaction and oxygen evolution reaction by virtue of electrochemical test, and has good circulating stability. The preparation method is simple in process procedures, easy in operation and good in application prospect.

The invention relates to the technical field of fuel batteries, and discloses novel use of a hydrophobing agent/conducting carbon material complex as an electro-catalyst carrier for a fuel battery. The complex can be taken as the electro-catalyst carrier for the fuel battery and used for preparing an electro-catalyst and an electrode. The invention also further discloses the electro-catalyst and the electrode prepared from the hydrophobing agent/conducting carbon material complex, and application thereof. As for the electro-catalyst prepared from the hydrophobing agent/conducting carbon material complex, the utilization rate of the catalyst is high; the transmission capability of reaction gas and reaction products is strong; the mass transfer polarization loss is small; the fuel battery assembled by the electro-catalyst has superior battery output performance; and the electro-catalyst is particularly suitable to be used in fuel batteries taking the air as an oxidant.

A difunctional negative electrode for an all-vanadium redox energy storage battery negative electrode includes a carbon matrix material and a Bi-containing electro-catalyst modifying the surface of the carbon matrix material. The negative electrode is suitable for being used as the negative electrode of the all-vanadium redox energy storage battery, can greatly improve the electrocatalytic activity and electrochemical reversibility of an electrode material on a V<2+>/V<3+> redox reaction, and decreases the charge transfer resistance; and the negative electrode has high hydrogen evolution overpotential, can inhibit a hydrogen evolution reaction, and prolongs the work life of the battery. The difunctional negative electrode improves the voltage efficiency and energy efficiency of the all-vanadium redox energy storage battery, so the working current density of the battery is improved, and the weight, the size and the cost of the battery with same output power are greatly reduced.

The invention relates to the relevant technical fields of energy and catalysis, in particular to a method for preparing a carbon-supported nano-platinum-chromium intermetallic compound serving as a cathode catalyst of a proton exchange membrane fuel cell. The invention provides a method for preparing the carbon-supported nano-platinum-chromium intermetallic compound serving as the cathode catalyst of the proton exchange membrane fuel cell on the basis of a metal carbonyl cluster compound. The method comprises the following steps: (1) synthesizing the metal carbonyl cluster compound serving as a catalyst precursor; (2) injecting a carbon support; (3) performing thermal treatment on a catalyst intermediate; (4) forming the intermetallic compound. According to the method for preparing the carbon-supported nano-platinum-chromium intermetallic compound serving as the cathode catalyst of the proton exchange membrane fuel cell on the basis of the metal carbonyl cluster compound, provided by the invention, the prepared nano-platinum-chromium intermetallic compound has the characteristics of uniform distribution, high electric catalytic oxidation reduction performance, high stability and the like.

A photoelectrochemical cell which includes a light transmissive enclosure, a semiconductor photoanode disposed within the light transmissive enclosure, a semiconductor photocathode disposed within the light transmissive enclosure, and an electrolytic solution disposed entirely between the semiconductor photoanode and the semiconductor photocathode. This is achieved by the use of semiconductor photoelectrodes (photoanodes and photocathodes) which include a proton exchange membrane having an electrolyte facing surface in contact with the electrolytic solution and a light transmissive wall facing surface, and having a photo electro-catalyst disposed on the light transmissive wall facing surface.

The invention relates to the field of electrochemical synthesis, in particular to a method for simultaneously preparing furfuryl alcohol in a cathode chamber and preparing furoic acid in an anode chamber on the basis of bipolar membrane technology, which has the effects of environmental protection, energy saving and emission reduction. By utilizing the principle that bipolar membranes are dissociated under the action of an electric field, hydrogen ions and hydroxide ions produced after water dissociation are respectively introduced into a cathode chamber and an anode chamber so as to regulatethe pH value of the reaction medium. The method electrooxidizes furfurol to prepare furoic acid in the anode chamber by utilizing an electro-catalyst MnO2/MnOOH, and the electro-catalyst can be repetitively used so as to have the effects of environmental protection, energy saving and emission reduction; the method reduces the furfurol to prepare furfuryl alcohol in the cathode chamber by utilizingthe furfurol as the raw material. Compared with the traditional process, the method eliminates the pollution of the catalyst chromium in the production of the furfuryl alcohol and the furoic acid, has the advantages of mild production condition and simple equipment, and is a novel process having the advantages of environmental protection and energy saving.