37results about How to "Excellent oxygen reduction catalytic activity" patented technology

The invention provides a preparation method for a nitrogen-doped carbon oxygen reduction catalyst with a hierarchical porous structure, belonging to the technical field of a fuel cell. The preparation method comprises the following steps of: firstly, preparing a eutectic molten salt having a three-dimensional macro-porous structure by a freeze drying method; secondly, using the eutectic molten salt as a template, doping a nitrogen-containing precursor, and leading the nitrogen-containing precursor to be oxidized and polymerized on the surface of the eutectic molten salt by a solid-phase polymerization method, wherein ammonium persulfate serves as an oxidizing agent, and a ferric salt serves as a promoter; and finally, carrying out high-temperature pyrolysis and removing the eutectic molten salt. With the adoption of the nitrogen-doped carbon oxygen reduction catalyst with the hierarchical porous structure, the nitrogen-containing precursor can be effectively prevented from pyrolysis loss, structural collapse and sintering during the high-temperature carbonation process, the catalyst yield and the nitrogen doping efficiency are improved, moreover, a large amount of micropores, mesoporous and macropores can be generated, and the mass transfer efficiency of oxygen and water is improved. The method is simple and practical, the production cost is low, and the prepared catalyst has excellent oxygen reduction catalytic activity and can substitute the traditional commercial Pt/C catalyst.

The invention belongs to the field of electrochemistry catalysis and particularly discloses a carbon-based non-metallic oxygen reduction catalyst as well as a preparation method and an application thereof. The carbon-based non-metallic oxygen reduction catalyst is a polymer which is prepared by doping other heteroatom (e.g. B, O, F, P, S, Cl, Br and I) derived from an N-contained polymerization product which is obtained by polymerizing aromatic nitrile compounds. The catalyst provided by the invention is high in conductivity, has a carbon skeleton structure with a high specific surface area and can be doped with many kinds of heteroatom. The catalyst has good oxygen reduction activity and high stability and is free from influence of methanol and carbon monoxide; besides, the catalyst is wide in application scope and is suitable for various systems containing oxygen reduction reaction, including a lithium air cell, a sodium air cell, kinds of fuel cells and so on; compared with an existing commercial platinum carbon (Pt/C) catalyst, the catalyst has the advantage of simple preparation, efficiency, environment friendliness, low cost and excellent performance.

The invention discloses a BaCoO3-delta base B-position Bi2O3-Nb2O5 co-doped cathode material of solid oxide fuel cell, a preparation method and applications thereof. The provided cathode material has a perovskite type structure and is represented by a chemical formula: BaBi<x>Nb<y>Co<1-x-y>O<3-delta>, wherein the delta represents oxygen excess or oxygen deficiency (-1=<delta=<1), the x represents the doping amount of Bi2O3 (0=<x=<0.15), and the y represents the doping amount of Nb2O5 (0=<y=<0.2). The chemical compatibility between the provided BaBi<x>Nb<y>Co<1-x-y>O<3-delta> cathode material and the conventional electrolyte material such as GDC, and the like is good. In the air the current can be well conducted by the oxygen ions and electrons. In the temperature range of 450 to 850 DEG C, the provided cathode material has a very good oxidation-reduction catalytic activity. The cathode material is suitable for a solid oxide fuel cell used at a mid-low temperature.

The invention relates to a hollow-structured transition metal cobalt and nitrogen co-doped carbon oxygen reduction catalyst as well as a preparation method and application thereof. A zeolite imidazatemetal organic framework material grows on the surface of a template by utilizing electrostatic interaction between sulfonic acid groups on the surfaces of microspheres and metal cobalt ions, and thenthe zeolite imidazate metal organic framework material is prepared by pyrolysis and carbonization in an inert atmosphere. According to the method provided by the invention, the active site utilization rate of the transition metal cobalt and nitrogen co-doped carbon catalyst can be effectively improved, the prepared catalyst can efficiently catalyze the oxygen reduction reaction of the cathode ofthe fuel cell, and the oxygen reduction catalytic activity is superior to that of commercial Pt/C.

The invention relates to a palladium/titanium dioxide/graphene catalyst and a preparation method thereof, belonging to the technical field of electrocatalysts. The catalyst comprises chemical components of Pd/TiO2/G, wherein G is the graphene, the TiO2/G is a catalyst carrier, the amorphous state TiO2 is uniformly covered on the surface of G, so that the corrosion resistance of G is improved, and the electrical conductivity of the TiO2 is improved by G,; the grain size of the catalytic activity component Pd is 2-4 nanometer, the Pd are uniformly distributed on the surface of the TiO2/G carrier. The catalyst has good electro-catalysis oxygen reduction activity, methyl alcohol resistance and stability. The preparation method of the catalyst comprises the following steps of uniformly covering the amorphous state TiO2 on the G through titanium compound hydrolysis so as to prepare a TiO2/G composite carrier, and loading the Pd particles on the TiO2/G composite carrier through low carbon alcohol reducing action, so as to prepare the Pd/TiO2/G catalyst. The preparation method has the characteristics of being simple in technology, easy to operate and the like.

The invention discloses a soybean biological base fuel cell oxygen reduction catalyst and a preparation thereof. The preparation method comprises the following steps of 1) preparing graphene oxide; 2)taking graphene oxide as a carrier and taking soybean as a carbon source, performing carbonization treatment through a hydrothermal method to obtain a precursor; and 3) performing pyrolysis and reduction on the precursor in an ammonia gas atmosphere to obtain the soybean biological base fuel cell oxygen reduction catalyst. The soybean biological base fuel cell oxygen reduction catalyst is used for catalyzing an oxygen reduction reaction of a fuel cell. The soybean biological base fuel cell oxygen reduction catalyst is prepared through a simple method by taking low-cost natural biomass soybeanas the raw material and by taking graphene as the carrier for performing pyrolysis and reduction in the ammonia gas atmosphere at a temperature of 800 DEG C. The catalyst is excellent in oxygen reduction performance and can be widely applied to the fuel cell.

The invention relates to a preparation method of an ionic liquid modified nitrogen-sulfur co-doped graphene oxide composite material. The method comprises the following steps: preparing a dispersion liquid from graphene oxide and deionized water, then mixing 1-aminopropyl-3-alkyl imidazole bromide salt, potassium hydroxide and the graphene oxide dispersion liquid, carrying out a reaction process to obtain a 1-aminopropyl-3-alkyl imidazole bromide salt and graphene oxide composite product, then mixing the product with thiourea, adding a solvent to dissolve the mixture, and reacting at 160-200 DEG C to obtain the composite material. The composite material is loaded on a cathode electrode to serve as a catalyst. The material obtained by the invention has good oxygen reduction catalytic activity and a wide application prospect.

The present disclosure relates to an electrocatalyst for oxygen reduction including a silver/silver halide composite, a fuel cell including the electrocatalyst for oxygen reduction, and a method for preparing the electrocatalyst for oxygen reduction.

The invention discloses a cathode material BaNbyZrxCo1-x-yO3-delta with an excellent thermal expansion coefficient for a solid oxide fuel cell. By co-doping Nb2O5 with ZrO2 at Co site of BaCoO3-deltato reduce the thermal expansion coefficient of a BaCoO3-delta base cathode material, a small TEC value (smaller than 15x10<-6>K<-1>) can be obtained and electrochemical properties of the material canbe further improved; a molecular formula is BaNbyZrxCo(1-x-y)O(3-delta), wherein delta represents excess oxygen content or oxygen deficiency content, and is greater than or equal to -1 and smaller than or equal to 1; x represents the doping amount of the ZrO2 and is greater than or equal to 0 and smaller than or equal to 0.5; y represents the doping amount of the Nb2O5 and is greater than or equalto 0 and smaller than or equal to 0.5. The BaNbyZrxCo(1-x-y)O(3-delta) cathode material disclosed by the invention, compared with traditional Co-based materials, has the advantage that the thermal expansion coefficient is greatly reduced; in addition, the BaNbyZrxCo(1-x-y)O(3-delta) cathode material has good chemical compatibility with GDC, good oxygen reduction catalytic activity in the temperature range of 500 to 850 DEG C and suitability for solid oxide fuel cell cathode materials at medium and low temperature.

The invention relates to the technical field of preparation of catalysts and provides a method for preparing an oxygen reduction catalyst based on tetra-beta-(4-formylphenoxy)phthalocyanine cobalt aerogel. The method comprises the following steps: (1) mixing tetra-beta-(4-formylphenoxy)phthalocyanine cobalt, an organic solvent and an acetic acid-amino enriched organic matter mixed solution, so asto obtain hydrogel; (2) soaking the hydrogel obtained in step (1) into water to remove the surplus solvent; after taking out the hydrogel, soaking the hydrogel into a graphene oxide solution or a multi-walled carbon nanotube solution and adsorbing, so as to obtain compound hydrogel; (3) carrying out freeze drying on the compound hydrogel obtained in step (2), so as to obtain compound aerogel; and(4) carrying out high-heat treatment on the compound aerogel obtained in step (3) under a protection atmosphere, so as to obtain the oxygen reduction catalyst. The invention further provides the oxygen reduction catalyst obtained by the method, and the oxygen reduction catalyst contains N, C and Co at the same time; and raw materials are easy to obtain and the oxygen reduction catalyst is easy toimplement. The product provided by the invention has excellent electrochemical performance and catalytic performance.

The invention provides a solid oxide fuel cell cathode material. The chemical formula of the cathode material is SrFe1-xMnxO3-delta, and x is not less than 0.05 and not more than 0.5. According to the cathode material disclosed by the invention, the SrFeO3-delta material is converted from a tetragonal phase to a cubic phase at room temperature by doping low-valence elements at a B site, has good oxygen reduction catalytic activity, shows excellent anti-carbon dioxide stability, and overcomes the defect that a common cathode is severely attenuated in a carbon dioxide-containing atmosphere; and the cathode material is an excellent carbon dioxide-resistant cathode material for the solid oxide fuel cell.

The invention discloses a high-entropy monatomic catalyst and a preparation method thereof. A specific embodiment of the preparation method of the high-entropy monatomic catalyst comprises the following steps: preparation of a mixed metal precursor: dissolving a carbon template precursor and a plurality of metal precursors in an acid solution to obtain a first mixed solution; the first mixed solution is evaporated to dryness in a reduced pressure distillation mode and then roasted in a muffle furnace, and a mixed metal precursor is obtained; preparation of a high-entropy monatomic catalyst: dissolving a mixed metal precursor and a carbon-coated precursor in a buffer solution to obtain a second mixed solution; and carrying out suction filtration on the second mixed solution, drying, and roasting in a tubular furnace to obtain the high-entropy monatomic catalyst. Therefore, five or more metal components can be uniformly loaded in the graphene-like carbon material in a monatomic form to form the high-entropy monatomic catalyst, so that the oxygen reduction catalytic activity of the high-entropy monatomic catalyst is improved.

The invention discloses a Pd-based passivation film with high catalytic activity and a preparation method thereof. A passivation film contains following components 80-90% of Pd and 10-20% of Ni by atomic percentage, the passivation film further includes one of Mo or Nb and contains following components 80-90% of Pd and 8-18% of Ni by atomic percentage, and the balance is Mo or Nb and not more than2%. The method comprises steps, 1), PdNi homogeneous solid solution, PdNiMo homogeneous solid solution or PdNiNb uniform solid solution are polished in a certain pressure range, the surface is made to be smooth, residual stress is injected, and polished sample is obtained; 2), the polished sample is subjected to constant pressure electrochemical etching in etching solution I to obtain a passivation film; and 3), the passivation film is placed in etching solution II and scanned by cyclic voltammetry, after that, the product is picked out and cleaned to obtain the Pd-based passivation film. Themethod is advantaged in that a problem of poor catalysis stability of a fuel cell in the prior art is solved.