127results about How to "High catalytic activity for oxygen reduction" patented technology

The invention discloses a lignin-based transition metal/nitrogen doped carbon material, and preparation and application thereof, belonging to the technical field of carbon materials. A preparation method comprises the following steps: (1) uniformly mixing a transition metal salt with lignin in water to obtain a lignin/transition metal salt mixed liquid; (2) subjecting the lignin/transition metal salt mixed liquid to hydrothermal pre-carbonization so as to obtain a hydrothermal pre-carbonization product; and (3) mixing the hydrothermal pre-carbonization product with a nitrogen source, carryingout high-temperature carbonization in a protective atmosphere, and carrying out subsequent treatment so as to obtain the lignin-based transition metal/nitrogen doped carbon material. The lignin-basedtransition metal/nitrogen doped carbon material of the invention has excellent electrochemical performance; and the preparation process of the material is simple, raw materials are widely available and cheap, and an effective way is provided for the high-value utilization of biomass. The carbon material of the invention is applied to fields of fuel cells, supercapacitors, adsorbent materials, and/or water electrolysis.

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.

The present invention relates to a nitrogen-doped graphene-iron-based nanoparticle composite catalyst and a preparation method thereof, wherein the catalyst is a complex of nitrogen-doped graphene and iron-based nanoparticles (including metal iron and iron nitride). The main preparation process comprises: carrying out a reaction of a graphene oxide aqueous solution and a reducing agent (hydrazine hydrate or sodium borohydride) for 1 h under an oil bath to obtain reduced graphene oxide; mixing the reduced graphene oxide aqueous solution and an iron salt, completely stirring, and carrying out freezing drying to obtain a reduced graphene oxide-iron salt aerogel precursor; and carrying out a high temperature heat treatment under a mixed atmosphere of ammonia gas and an inert gas to obtain the nitrogen-doped graphene and iron-based nanoparticle complex. Compared with the commercial platinum-carbon catalyst, the composite non-precious metal catalyst of the present invention has advantages of simple preparation process, low cost, high oxygen reduction catalysis activity, good methanol tolerance and the like, and can be used for fuel cells, lithium-air batteries and other oxygen reduction catalysis reaction systems.

The invention discloses an M-N-C oxygen reduction catalyst and a preparation method thereof, wherein the raw materials of the catalyst comprise a copolymer (P(TPT+Py)) of tripyrrole-[1,3,5]-triazine (TPT) and pyrrole (Py) and a non-noble metal salt. The preparation method comprises: (1) using a Friedel-Crafts reaction to synthesize a copolymer (P(TPT+Py)) of tripyrrole-[1,3,5]-triazine (TPT) and pyrrole (Py); (2) adding (P(TPT+Py)) and a non-noble metal salt to ethanol, placing into an ultrasonic dispersion device, carrying out an ultrasonic treatment to make the whole system be uniformly dispersed, evaporating the ethanol, placing into a vacuum oven, and drying for 4 h at a temperature of 80 DEG C; (3) carrying out a first heat treatment to obtain a nitrogen-doped carbon material; (4) completely washing the obtained nitrogen-doped carbon material with a diluted acid; and (5) carrying out a second heat treatment so as to obtain the M-N-C oxygen reduction catalyst.

The invention provides a nitrogen and iron modified carbon material, belonging to the technical field of composite materials. The material takes melamine and FeCl3 as modifiers, and active ingredients such as N, Fe and the like are doped in carbon powder/a carbon nano tube, so that the catalytic action of the carbon material on oxygen reduction reaction is effectively improved, and the carbon material has good catalytic activity. Therefore, the carbon material can be applied to oxygen reduction catalytic reaction of fuel cells as a catalyst material. Through experimental determination, the cathode electrodes of the fuel cells prepared from the material show better oxygen reduction properties than traditional commercial XC-72 carbon powder electrodes, and the oxygen reduction catalytic activity is obviously improved. The material is simple in preparation process, is environment-friendly and is a non-noble metal oxygen reduction catalyst with potential application.

The invention relates to a catalyst for VIII group single atomic dispersion and a preparation method thereof. The catalyst is a nonmetal heteroatom doped carbon carrier formed by carrying out coordination on VIII group atoms and Zn atoms as well as organic ligands to form a metal organic framework, then carrying out high temperature pyrolysis reaction in presence of inert gas and carrying out coordination with organic ligands, wherein the VIII groups atoms interact with the nonmetal heteroatoms, are coated in a carbon layer and exist in a single atom form. According to the invention, the metalorganic framework is taken as a precursor, the required catalyst can be prepared by adopting a high temperature pyrolysis method only, and the preparation method is simple and practicable and is a universal method for synthesizing single atoms. The provided catalyst for the VIII group single atomic dispersion has good thermal stability and shows good catalytic activity in catalysis of oxygen reduction of a cathode of a fuel cell.

The invention relates to a method for preparing nitrogen self-doped three-dimensional graphene from peels. With peels as a carbon source and a nitrogen source, the method comprises the following steps: performing hydrothermal carbonization; performing activation treatment using an activator; and performing acid washing and drying to obtain the nitrogen self-doped three-dimensional graphene. In the invention, since the peels are selected as a raw material for preparing the nitrogen self-doped three-dimensional graphene, the needs for sustainable development and environmental protection can be met, and the raw material cost is effectively reduced. The specific surface area of the prepared product exceeds 1700m<2>g<-1>; the relatively large specific surface area and three-dimensional graphene porous structure are beneficial to the transfer and transport of ions in the electrolyte; and the electrical conductivity is very good. Due to the doping of nitrogen element, active sites for catalysis and lithium storage reactions can be formed, and the nitrogen self-doped three-dimensional graphene can be widely applied to the fields of energy storage and transformation such as fuel cells and lithium ion batteries. Moreover, the graphene material has excellent electrical conductivity, and the carbon material has relatively high activity due to the doping of nitrogen element.

The invention relates to an electrocatalyst of a negative electrode of a fuel cell as well as a preparation method and application of the electrocatalyst. The catalyst adopts a conductive polymer as a reaction precursor, the conductive polymer is polymerized under the acid and oxidation condition to obtain polyaniline, the polyaniline is additionally provided with transition metal salt, and a phosphorus compound and/or a boron compound as a precursor, and the mixture is dried and is subjected to pyrolysis at the high temperature to obtain the electrocatalyst. The catalyst is N, phosphorus and/or boron co-doped nanometer carbon with a porous nanometer structure; the total mass percent of the doped heteroatom is 0.2 to 15 percent, the mass ratio of N to phosphorus and/or boron is 5:1 to 100:1, the weight percentage of metal is 0.1 to 10 percent, and the mass percent of the nanometer carbon is 75.0 to 99.7 percent.

The invention provides a preparation method of a supported platinum-based alloy catalyst. The catalyst can be used as a low temperature fuel cell catalyst. The preparation method comprises the steps of taking ethylene glycol as a solvent and stabilizer, dispersing a carrier in the solvent, and reducing platinum and non-platinum precursors by strong reducing agents such as borohydride, hydrazine hydrate and tetrabutyl borohydride to obtain supported platinum-based alloy nanoparticles. The preparation method adopted by the invention is simple, effective and free of a problem of difficult removalof the stabilizer. The prepared alloy catalyst has a small particle size and uniform particle size distribution, and has good dispersion on the carrier at the same time. In addition, the catalyst canshow high area specific activity and unit mass Pt specific activity for oxygen reduction reaction, can effectively reduce the platinum consumption and has potential application prospects in the low temperature fuel cell.

The invention relates to a catalyst, in particular to phosphorus-doped graphene oxygen reduction electro-catalyst and a preparation method and application thereof. The phosphorus-doped graphene oxygen reduction electro-catalyst contains oxidized graphene substrate and active phosphorus doped or attached to the surface and inside of the oxidized graphene substrate. The preparation method includes the steps of 1, preparing the oxidized graphene; 2, mixing the oxidized graphene with phosphorus-bearing precursor; 3, drying; 4, performing pyrolysis. The phosphorus-doped graphene oxygen reduction electro-catalyst is good oxygen reduction electro-catalyst, is high in catalytic activity and resistant to methanol poisoning and carbon monoxide poisoning, good in stability and capable of serving as electro-catalyst for fuel cells and metal-air cells and serving as electrode active material for electrochemical energy storage and conversion devices such as lithium ion cells, sodium ion cells, lithium-sulfur cells and supercapacitors, and is also applicable to the fields such as electrochemistry/biosensors.

The invention discloses a metal-doped nitrogen-containing carbon gel catalyst used for proton exchange membrane fuel cell cathode and its preparation method, a nitrogenous aromatic compound and aldehyde are taken as a reaction precursor, a reaction monomer is subjected to an addition reaction and a condensation polymerization through base catalysis, and a metallic element is simultaneously added to prepare a metal-doped hydrogel, the metal-doped hydrogel is subjected to processes of drying, pyrolysis and secondary nitridation to obtain the metal-doped nitrogen-containing carbon gel nano charcoal material. When the catalyst of the present invention is used as the anode catalyst of the proton exchange membrane fuel cell, the catalyst indicates excellent reduction activity, the catalyst has the advantages of environmental protection, low cost, microscopic control and abundant resource, and is expected to be an electrocatalyst of the proton exchange membrane fuel cell.

The invention discloses an M-N-C oxygen reduction catalyst and a preparation method thereof. The catalyst comprises the following raw materials: a polymer P(TPT) of tripyrrole-[1,3,5]-triazine (TPT) and a non-noble metal salt; and the preparation method comprises the following steps: (1) synthesizing the polymer P(TPT) of tripyrrole-[1,3,5]-triazine (TPT) through a Friedel-Crafts reaction; (2) adding the P(TPT) and the non-noble metal salt to ethanol, putting the mixture in an ultrasonic dispersion instrument and carrying out ultrasonic treatment to make the whole system uniform in dispersion, evaporating the ethanol to dryness, and drying in a vacuum drying oven at 80 DEG C for 4 hours; (3) carrying out first heat treatment to obtain a nitrogen-doped carbon material; (4) fully washing the obtained nitrogen-doped carbon material with dilute acid; and (5) carrying out second heat treatment, so as to obtain the M-N-C oxygen reduction catalyst.

The invention provides a preparation method and application of a nitrogen-doped porous carbon-coated cobalt nanoparticle composite material. The preparation method comprises the following steps: uniformly dispersing a carbon source precursor, a nitrogen source precursor and soluble salt of transition metal ions in a solvent according to a ratio, then performing drying to obtain a solid powder precursor, and calcining the solid powder precursor in a protective atmosphere to obtain black powder, namely the composite material. The composite material has efficient oxygen reduction catalysis performances and can be applied to proton exchange membrane fuel cells, alkaline fuel cells and metal-air batteries. The catalyst has the advantages that a pore structure is generated in the heat treatmentprocess and is uniformly dispersed; the carbon source, the nitrogen source and the metal source interact with one another to stabilize active elements and effectively improve the catalytic activity. Compared with a catalyst with commercial carbon as a carbon source, the prepared composite material has better oxygen reduction catalytic activity and is an efficient non-noble metal oxygen reduction catalyst.

The invention discloses a catalyst for a negative electrode material of a hydrogen-air fuel battery and a preparation method thereof. In the invention, according to the catalyst, group VIII atoms anda Zn atom are coordinated together with an organic ligand to form a metal organic framework, then at least one additional group VIII atom is adsorbed by a double-solvent method, next a high-temperature pyrolysis reaction is performed in an inert gas atmosphere, the organic ligand is coordinated to form a non-metal heteroatom-doped carbon carrier, and the group VIII atoms and a non-metal heteroatomare interacted, are coated in a carbon layer and exist in a multi-atom form. Based on the metal organic framework as a precursor, the required catalyst can be prepared only by the high-temperature pyrolysis method. The preparation method is simple and feasible, and is a universal method for synthesis of multiple atoms. The group VIII multi-atom dispersed catalyst provided by the invention has good thermal stability and has excellent catalytic activity on oxygen reduction catalysis of a negative electrode of the hydrogen-air fuel battery.

The invention provides a method for synthesizing a nitrogen-carbon compound nonmetal reducing catalyst by utilizing concentrated sulfuric acid carbonization. The method utilizing an organic compound containing carbon, hydrogen and oxygen as a carbon source and utilizing melamine as a nitrogen source comprises the following steps of: preliminarily carbonizing the hydrogen and the oxygen in the organic compound containing the carbon, the hydrogen and the oxygen by utilizing dehydration characteristic of the concentrated sulfuric acid, so that the melamine enters a duct of the preliminary carbonizing product, and the nitrogen source is effectively fixed; carrying out high-temperature deep carbonization under the protection of the nitrogen gas to obtain a compound material which is effectively combined with the nitrogen and the carbon, so that the active nitrogen with the effect of promoting oxygen reduction catalysis has a good effect, and therefore, a nitrogen loss problem generated by the conventional high-temperature treatment method is avoided, and the oxygen reduction catalysis activity of the nitrogen-carbon composite material is effectively improved.

The invention relates to a high-catalytic activity composite negative electrode material of an intermediate-temperature solid oxide fuel cell and a preparation method of the composite negative electrode material, and belongs to the technical field of an energy material. The composite negative electrode comprises a perovskite structured oxide PrBa<1-x>Co<2>O<6-Delta>, Pr<1-y>BaCo<2>O<6-Delta> or Pr<1-n>Ba<1-m>Co<2>O<6-Delta> in the absence of A-position cation and an oxygen ion conductor material Sm<0.2>Ce<0.8>O<1.9> or Gd<0.1>Ce<0.9>O<1.95>, wherein the mass percent of the oxygen ion conductor material accounts for 20-50%. The preparation method of the composite negative electrode material comprises the following steps of firstly, respectively preparing synthesis solutions of two constituents; secondly, mixing and uniformly stirring the two solutions to obtain a mixed synthesis solution of the two constituents, and heating the mixed synthesis solution to obtain mixed precursor gel; and finally, carrying out high-temperature sintering reaction to obtain composite negative electrode powder. The composite negative electrode material is prepared by a synchronous sintering reaction method, the preparation method has the advantages of simplicity in process, short preparation period, low cost and high efficiency, and is easy to operate, and the oxygen reduction catalytic activity of the negative electrode of the intermediate-temperature solid oxide fuel cell is effectively improved.

The invention provides an N-and-P double-doped carbon fiber-loaded CoP composite catalytic material as well as a preparation method and application thereof, belonging to the field of aluminum air batteries. The preparation method comprises the following steps: mixing a ZIF-67 organic solution and a polyacrylonitrile organic solution to obtain a spinning precursor solution; performing electrostatic spinning on the spinning precursor solution to obtain a flexible film; pre-oxidizing the flexible film to obtain a pre-oxidized product; and mixing the pre-oxidized product with red phosphorus, and carrying out pyrolysis in a protective atmosphere to obtain the CoP@G/NP-PCNFs composite material. According to the invention, ZIF-67 particles have an atomic-level confinement dispersion effect on the Co element, and are combined with electrostatic spinning, and carbonization and phosphorization are carried out in a pyrolysis process, so the formed carbon fibers have relatively high conductivity; and the carbon spheres derived from the ZIF-67 particles wrap the CoP particles, so an ORR reaction can be promoted to conducted in a four-electron path, and battery efficiency is improved.

The invention discloses a high-performance alkaline fuel cell cathode carbon catalyst and a preparation method of the high-performance alkaline fuel cell cathode carbon catalyst. The catalyst disclosed by the invention is a composite carbon material in a core-shell nanostructure, which is prepared by adulterating two elements of Fe and N, using conductive carbon black with a high-ratio surface as an inner core and coating a phthalocyanine iron shell around the inner core. The preparation method comprises the following steps of: weighing and mixing phthalocyanine iron solid powder and the conductive carbon black with the high-ratio surface according to a certain mass ratio, and then preparing to obtain a C@FePc carbon non-noble metal catalyst in the core-shell nanostructure by adopting a simple mechanical ball milling method. The catalyst disclosed by the invention has high-performance oxygen reduction reaction (ORR) catalytic activity, excellent CH3OH/CO tolerance and good stability, the cost of raw materials used in the preparation process is low, the operation is simple and convenient, and the catalyst is easy for large-scale commercialized production.

The invention discloses a catalyst prepared by in-situ growth of carbon nanotubes on ordered mesoporous carbon, and a preparation method and an application of the catalyst. The composite catalyst is prepared by performing in-situ growth of carbon nanotubes on nitrogen-doped ordered mesoporous carbon; equivalently, a triblock copolymer is used as a soft template agent, and a soluble resin is used as a carbon source; transitional metal salt is added in the preparation process; a transitional metal element is introduced in an in-situ manner; and meanwhile, active points which facilitate growth of the carbon nanotubes are generated under mixed atmosphere of ammonia gas and hydrocarbons based on the transitional metal components introduced in a modifying process of the ordered mesoporous carbon material so as to realize nitridation and growth of carbon nanotubes in one step. The composite catalyst prepared by in-situ growth of carbon nanotubes on ordered mesoporous carbon has large activity specific surface and high conductivity performance, and shows excellent oxygen reduction catalytic performance and high electrochemical stability.

The invention discloses a core shell carbon nano-structure electrocatalyst with high catalytic performance and a preparation method thereof. Phthalocyanine iron having an enclosed edge structure is used as a shell, a conductive carbon is used as a core, and an Fe-N4 central structure of iron phthalocyanine unit is used as an active site. The preparation method comprises the following steps: 1), adding the conductive carbon into a mixed solution of pyromellitic dianhydride and phthalic anhydride, and performing drying to obtain powder A; 2), uniformly mixing the powder A with an iron compound,ammonium molybdate and urea to obtain powder B, heating to ensure that the powder B is a fused solution, performing microwave reaction to ensure that in-site polymerization reaction is carried out, and performing washing and drying to obtain the core shell carbon nano-structure electrocatalyst with the high catalytic performance. Being obviously superior to commercial Pt/C catalyst, the novel core shell carbon catalyst disclosed by the invention has excellent high oxygen reduction catalytic activity, excellent circulation stability and excellent CH3OH/CO tolerance; the raw materials used by synthesis of the catalyst are market developed products and are low in cost; the preparation process is simple and feasible, and is suitable for commercial mass production.

The invention discloses a carbon-doped nano-catalyst as well as a preparation method and an application thereof. The preparation method comprises steps as follows: a whole boiled egg is ground, dehydrated and mixed with g-C3N4, the mass ratio of the dehydrated egg to g-C3N4 is 0.5-2, the mixture is ground uniformly and put in a tube furnace, nitrogen is introduced for protection, the mixture is calcined at the temperature of 800-1,000 DEG C for 1-3 h at the heating speed of 5-15 DEG C/min, and the carbon-doped nano-catalyst is obtained. Raw materials required for the carbon-doped nano-catalyst are cheap, the method is simple, the yield is high, the carbon-doped nano-catalyst with the best catalysis effect is obtained by changing the proportion of raw materials and the heating speed, and the carbon-doped nano-catalyst can replace expensive Pt/C (20%) to a certain extent in the aspect of oxygen reduction effect under the neutrality condition.