1675results about How to "Many active sites" patented technology

The invention discloses a nitrogen-doped carbon nano-material, a preparation method of the nitrogen-doped carbon nano-material and an application of the nitrogen-doped carbon nano-material to preparation of a negative electrode material of a fuel cell. The nitrogen-doped carbon nano-material is prepared from the components of nitrogen-containing heterocyclic compounds and a carbon nano-material, wherein the mass content of nitrogen is 2-10.4 percent. The preparation method comprises the steps of (1) uniformly mixing the surface-active carbon nano-material and a nitrogen-containing complex according to the mass proportion of 1 to (1-5), thus obtaining a precursor mixture; and (2) under the protective gas environment, raising the temperature of the precursor mixture obtained in the first step to 800-1,000 DEG C, and calcining for 2-40 hours. The nitrogen-doped carbon nano-material provided by the invention shows preferable oxygen reduction catalysis performance; the preparation method provided by the invention can be applied to various carbon nano-materials and is good in the adaptation; with the adoption of the preparation method, the whole preparation process is simple and easy to operate and is suitable and low in the cost.

The invention relates to a novel composite material, and particularly relates to a preparation method and application of a nitrogen-doped graphene and cobaltosic oxide hollow nanosphere composite material. The novel composite material comprises a doped graphene substrate and cobaltosic oxide hollow nanospheres which is attached to the surface of the doped graphene substrate. Melamine resin is taken as a cross-linking reagent for integrating graphite oxide with Co<2+> into a single coordination precursor. The preparation method comprises the following steps: in a pyrolysis process of the precursor, taking the melamine resin as a new nitrogen source to uniformly dope the graphene with nitrogen, fixing cobalt oxide which is generated in situ, and finally preparing the nitrogen-doped graphene/Co3O4 hollow nanosphere composite material with a sandwich structure. The composite material has a graded porous structure, is high in specific surface area, more in active sties, good in electron conductivity and ion conductivity, and good in application prospect in the field of new energy resources and catalysis.

The invention belongs to the technical field of electrocatalysis and particularly relates to an iron-doped bimetal phosphide electrocatalyst and a preparation method and application thereof. A hydroxide precursor synthesized by a hydrothermal reaction undergoes a phosphating reaction at a low temperature to produce a Ni1CoxFeyP nanosheet array electrocatalyst. The bimetal phosphide has low chargetransfer resistance and a reaction barrier for a hydrogen evolution reaction and has superior performances in the electrocatalytic hydrogen evolution reaction. The catalyst has a low cost. The preparation method is easy to operate and has simple processes. The electrocatalyst has excellent catalytic performances and provides the basic application research for the material in the field of electrocatalysis.

The invention discloses a preparation method of a nitrogen-doped graphene loaded platinum nano-particle catalyst. The preparation method comprises the following steps of: firstly, preparing graphene oxide (GO); secondly, preparing polyaniline/graphene oxide (PANI/GO) through a liquid-liquid interface polymerization method; thirdly, drying the PANI/GO, transferring the dried PANI/GO into a tubular furnace, and performing high-temperature treatment for 2 hours at 800 DEG C to prepare NGs (nitrogen-doped graphenes); and finally, ultrasonically dispersing the NGs into an aqueous solution, uniformly mixing the NGs with chloroplatinic acid according to a certain mass ratio, slowly adding sodium borohydride (NaBH4) into the mixed solution, and performing magnetic stirring for 8 hours to prepare the NGs loaded platinum nano-particle catalyst (Pt/NGs) which takes the NGs as a catalyst carrier to uniformly load platinum nano-particles to the surfaces of the NGs without any chemical modification. The nitrogen atoms which are doped into molecular structures of GNs not only provide a large amount of active sites for PtNPs loading, but also enhance the interaction between the PtNPs and an NGs carrier and improve the catalytic stability and catalytic activity of a nano composite material.

The invention discloses a preparation method for a sludge carbon based Fenton-like catalyst. The preparation method uses sludge as a raw material to prepare active carbon with high specific surface area through pyrolysis, and loads iron with the active carbon as a carrier to prepare a high-activity catalyst. The preparation method comprises the following steps: drying the sludge, then carrying out grinding and sieving, carrying out activation with a composite activator, after the completion of activation, carrying out high-temperature anaerobic pyrolysis with a certain heating program so as to prepare sludge carbon, then carrying out pickling, washing, drying, grinding and sieving so as to obtain sludge active carbon with high specific surface area, with the sludge active carbon as a carrier, carrying out impregnating in ferrous sulfate for 1 h, carrying out stirring for 24 h, carrying out drying for 12 h, and calcining the dried active carbon so as to prepare a high-activity sludge carbon based catalyst. The invention provides an effective method for sludge recycling; the catalyst prepared by using the method provided by the invention has high specific surface area and a plurality of active sites, so activity is extremely high; and by utilizing the catalyst provided by the invention, azo dye rhodamine B in water can be effectively removed.

The invention discloses a preparation method and products of a non-noble metal catalyst. The preparation method of the non-noble metal catalyst comprises the steps of dissolving two metal salts and an organic ligand proportionally in an organic solvent respectively, mixing well, standing a solution at room temperature, and centrifuging or filtering and fully drying to obtain a precursor; subjecting the precursor to high-temperature pyrolysis in an inert atmosphere to obtain the non-noble metal catalyst; the prepared non-noble metal catalyst is a nano-structure carbon material with cobalt and another metal element co-doped, with MOF structure as a core and with carbon nanotubes grown on the surface; the non-noble metal catalyst prepared herein has high redox catalytic activity and stability and excellent CH3OH/CO tolerance in acidic electrolyte, the cost for the materials used herein is low, the preparation method is simple and convenient and is easy to perform.

The invention provides a nitrogen-phosphorus codoped carbon loaded molybdenum carbide or tungsten carbide catalyst and a preparing method and application thereof. The preparing method includes the following steps that a coprecipitation method is used for preparing a SEP compound material from a surfactant and heteropolyacid or polyoxometalate, the surfactant is a cationic surfactant or ionic liquid surfactant, and the heteropolyacid or polyoxometalate contains molybdenum or tungsten; the SEP compound material, melamine and phytic acid are used as raw materials for synthesizing a SEP-MA-PA compound material through a mixing and dissolving method; under protection of inert gas, the SEP-MA-PA compound material is subjected to heat treatment and cooled to obtain the nitrogen-phosphorus codopedcarbon loaded molybdenum carbide or tungsten carbide catalyst. Nanoparticles of the nitrogen-phosphorus codoped carbon loaded molybdenum carbide or tungsten carbide catalyst are small in size and areof a porous structure, by means of nitrogen-phosphorus heteroatom doping, the conductivity of the catalyst is enhanced, and the catalyst has efficient performance of electrolyzing water for preparinghydrogen.

The invention relates to a cobalt sulfide/layered double metal hydroxide composite electrocatalyst and a preparation method thereof, and belongs to the technical field of electrocatalysts. Co9S8/NF with a good stability and a good conductivity is used as a precursor, and nanosheets with a high specific surface area and uniform composition are loaded on the surface of the precursor in a compoundingmanner to prepare the cobalt sulfide/nickel-iron layered double metal hydroxide/ foamed nickel composite electrocatalyst. The prepared material can be used for electrocatalytic hydrogen evolution andoxygen evolution, has a good electrocatalytic performance, is of great significance to prepare, develop and apply the cobalt sulfide/layered double metal hydroxide composite electrocatalyst, and hasa broad application prospect in fields of electrocatalytic hydrogen evolution and oxygen evolution.

The invention belongs to the field of electrocatalysts, and specifically relates to a preparation method and application of a mesoporous bi-metal phosphide electrocatalyst for electrochemically decomposing water to generate hydrogen with high performance. A hydroxide precursor is synthesized through hydrothermal reaction and is further subjected to low-temperature phosphating reaction to obtain aNixMn1P porous nanosheet array electrocatalyst. The series of bi-metal phosphides have relatively low charge transfer resistance and reaction barrier of hydrogen evolution reaction, and have excellentperformances in electro-catalytic hydrogen evolution reaction. The catalyst is low in cost, is simple and convenient in operation, is simple in process, is excellent in catalysis performance, and provides basic application research, in the electro-catalysis field, of the materials.

The invention relates to a nano-high-entropy alloy electrocatalyst and a preparation method thereof, and belongs to the technical field of new material preparation. The material is composed of a three-dimensional porous carbon substrate and FeCoNiCrCu high-entropy alloy nanoparticles loaded on the three-dimensional porous carbon substrate; the nanoparticles are an FeNi alloy structure monoclinic system, and the space group is Pm6; the molar ratio of Fe to Co to Ni to Cr to Cu is 1:1:1:1:1. The preparation method comprises the following steps: 1) dissolving a template agent-sodium chloride, a carbon source, and urea with deionized water, adding a doping source, magnetically stirring and freezing until totally solid, and then performing vacuum drying; 2) performing heat treatment and then cooling to room temperature to obtain powder; 3) washing, filtering and drying the powder to obtain the nano-high-entropy alloy electrocatalyst; 4) producing the nano-high-entropy alloy electrocatalyst into a working electrode and performing electrochemical performance test. The diameter of the nano-high-entropy alloy nanoparticles is 10 to 100 nm; according to a reaction of oxygen evolution through catalysis of the high-entropy alloy electrocatalyst, the initial potential is 1.50 to 1.63 V, the overpotential is 360 to 460 mV when the current density is 10 mA cm<-2>, and the Tafel slope is 70 to 120 mV dec<-1>.

The invention discloses a preparation method of an alkali oxygen evolution reaction electrocatalyst. The preparation method comprises the following steps: firstly, carrying out ultrasonic cleaning on a conductive substrate, then preparing aqueous solution with soluble cobalt salt, soluble manganese salt, ammonium fluoride and urea, and in a reaction kettle, vertically growing a manganese cobalt subcarbonate nano array multilevel structure on the surface of the substrate; then preparing aqueous solution with soluble alkali and a reducing agent, carrying out secondary treatment, and carrying out structure and performance optimization on the manganese cobalt subcarbonate nano array multilevel structure; finally, in a tube furnace, in nitrogen or argon atmosphere, carrying out calcination at a temperature of 200 to 1,000 DEG C to prepare the alkali oxygen evolution reaction electrocatalyst with a manganese-doped cobalt oxide nano array multilevel structure. The preparation method disclosed by the invention adopts a simple hydro-thermal synthesis/calcination treatment method, is simple in process and is easy to regulate and control; the prepared product is excellent in performance and is an electrocatalyst with wide prospect in the application process of alkali water decomposition.

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 discloses a selective hydrogenation catalyst for producing biodiesel and a preparation method and application of the selective hydrogenation catalyst. The selective hydrogenation catalyst comprises a carrier and a main metal active ingredient loaded on the carrier, the main metal active ingredient accounts for 5-30% of the catalyst in weight and is one of or a combination of oxides containing Co, Mo, Ni and W, and the carrier is composed of, by weight, 1-8% of a molecular sieved, 25-65% of amorphous sial, 30-65% of alumina and 2-10% of a graphene auxiliary. The preparation method includes: disposing the carrier in a metal salt solution containing Co, Mo, Ni or/and W for soaking for 4-20 h to obtain a soaked carrier; freeze-drying and then calcining the soaked carrier to obtain the selective hydrogenation catalyst. With same carrying capacity of the carrier, active surface area represented by the carrier is large, the selective hydrogenation catalyst has more active sites, reaction temperature is lowered, and hydrogenation performance is improved.

The invention discloses a manganese dioxide composite material. The manganese dioxide composite material is composed of delta-MnO2 nano sheets and nano secondary particles assembled by nano carbon, wherein the nano secondary particles have a porous structure. The invention also provides a preparation method of the manganese dioxide composite material and an application of the manganese dioxide composite material in removing formaldehyde. The manganese dioxide composite material provided by the invention can rapidly catalyze the degradation of formaldehyde at a low temperature/room temperature,and the removal rate of formaldehyde is high. The preparation method of the manganese dioxide composite material provided by the invention is simple and is easy to operate, and the production cost islow.

The invention relates to a nickel foam-loaded silver-doped nickel-based bimetallic hydroxide electrocatalytic hydrogen evolution catalyst and a preparation method thereof. The catalyst takes foam nickel as a carrier, nickel-based bimetallic hydroxide of a laminated structure is uniformly arranged and grows on the surface of foam nickel, and nano-silver particles are uniformly attached to the surface of the nickel-based bimetallic hydroxide. The nickel foam-loaded silver-doped nickel-based bimetallic hydroxide electrocatalytic hydrogen evolution catalyst takes three-dimensional porous foam nickel of a net structure as a carrier, the nickel-based bimetallic is combined with the carrier firmly, distribution is uniform, the catalyst has the good catalytic hydrogen evolution effect under the alkaline condition, and the stable catalytic activity can be kept in a long time.

The invention discloses a Fe-Co-P-C amorphous electro-catalyst for an efficient hydrogen evolution reaction and a preparation method thereof. The Fe-Co-P-C amorphous electro-catalyst for the efficient hydrogen evolution reaction is characterized in that the electro-catalyst is a Fe-Co-P-C amorphous alloy strip, components of the electro-catalyst are Fe(80-x)CoxP(20-y)Cy, 0<=x<=50, 0<=y<=15, and x and y are correspondingly the atomic percent of Co and the atomic percent of C in the Fe-Co-P-C amorphous alloy strip. The Fe-Co-P-C amorphous electro-catalyst is prepared by adopting a melt rotary quenching method, the preparation method is simple, easy to operate, low in cost and friendly to environment, the whole preparation process does not need special equipment, large-scale industrial production can be achieved, and the quality of the obtained alloy strip is high; and according to the prepared Fe-Co-P-C strip through the preparation method, the advantages of being good in conductivity, large in number of active sites, high in electro-catalytic performance and the like are achieved simultaneously, and the Fe-Co-P-C amorphous electro-catalyst is a hydrogen evolution electro-catalytic material which has the wide industrial application prospect.

The invention discloses double-shell-layer and yolk-shell-layer nitrogen-doped hollow porous carbon and preparation methods thereof and application thereof. A ZIF-8@ZIF-67@ZIF-8@ZIF-67 four-layer nuclear shell structure, a ZIF-67@ZIF-8@ZIF-67 three-layer nuclear shell structure and a ZIF-67@ZIF-8@ZIF-67@ZIF-8@ZIF-67 five-layer nuclear shell structure are prepared at a room temperature and the prepared nuclear shell structures are used as precursors; carbonization is carried out directly to obtain double-shell-layer, yolk-single-shell-layer, and yolk-double-shell-layer nitrogen-doped hollow porous carbon. According to the invention, the preparation method is simple and controllable; and production and scaling up can be realized; and the obtained nitrogen-doped hollow porous carbon has characteristics of large specific surface area, nitrogen doping, graphitization, hierarchical pore structure, and hollow and hole structure and has the excellent electrochemical performance. The nitrogen-doped hollow porous carbon can be used as a supercapacitor electrode material.

The invention belongs to the field of nanomaterials, and discloses a nickel-cobalt bimetallic phosphide electrocatalyst as well as a synthesis method and an application thereof. The Prussian blue analogue precursor synthesized through simple aging reaction is further subjected to low-temperature phosphating reaction, and a NiCoP multi-hollow porous nanocube electrocatalyst is obtained. The seriesof bimetallic phosphides have lower charge transfer resistance and reaction barrier for oxygen evolution reaction, and have superior performance in electrocatalytic oxygen evolution reaction. Besides,the catalyst is low in cost and convenient to operate, adopts a simple process and has superior catalytic performance, and basic application research is provided for the materials in the field of electrocatalysis.

The invention discloses a simple preparation method for a one-piece high load copper base catalyst, which belongs to the technical field of catalyst preparation. Precursors of a metal oxide and active metal are blended at high speed by using a colloid mill, the nucleation process and the crystallization process of precursors of a carrier and an active component are isolated to obtain highly dispersed hydroxide nanoparticle sol, and finally the one-piece high load copper base catalyst which is controllable in metal nucleus diameter and uniform in dispersion is prepared by roasting and reduction. The one-piece high load copper base catalyst is characterized in that nano metal copper is dispersed and anchored in a single magnesium oxide substrate, the specific surface area is 50 to 150 m<2>/g, and the percentage mass content of the copper is 50 to 90 %. After the catalyst is used for hydrogenation preparation of 1, 4-cyclohexanedimethanol by 1, 4-dimethyl cyclohexanedicarboxylic acid and hydrogenation preparation of furfuryl alcohol by furfural, the reaction conversion rate can reach 90 to 99%, and the selectivity to a main product reaches 90 to 99%.

The invention discloses a three-dimensional nitrogen-boron co-doped graphene aerogel preparation method, which comprises: (1) preparing graphene oxide by using an improved Hummers method; (2) preparing polyhydroxy boron nitride by using an atom substitution method; and (3) preparing a nitrogen-boron co-doped graphene hydrogel having a three-dimensional structure by using the graphene oxide as a substrate, by using the polyhydroxy boron nitride as a nitrogen source and a boron source through a solvothermal method, and carrying out freeze-drying to obtain the composite aerogel. Compared to the pure graphene gel, the composite material of the present invention has characteristics of large specific surface area and good pore channel structure.; and by doping the nitrogen atom and the boron atom, the material has the more active sites so as to provide wide application prospect.

The invention discloses a silicon-nitrogen doped carbon-nitrogen doped graphene composite material. The silicon-nitrogen doped carbon-nitrogen doped graphene composite material is formed by graphene oxide, a nitrogen-containing carbon source and silicon, wherein a mass ratio of graphene oxide to the nitrogen-containing carbon source to silicon is 1-4:2:2-6; and nitrogen doped carbon with a core-shell structure is obtained through a solution mixing process and a high temperature charring process, and coats silicon particles, and the nitrogen doped carbon coated silicon particles are uniformly inlaid in nitrogen doped graphene interlayer. A preparation method of the composite material comprises the following steps: adding a nitrogen-containing carbon source solution into a silicon dispersion, and carrying out stirring ultrasonic treatment; adding a graphene oxide dispersion solution to the above obtained mixed solution in the ultrasonic process; and carrying out stirring heating, evaporation pulping, freeze drying and high temperature charring in order to obtain the silicon-nitrogen doped carbon-nitrogen doped graphene composite material. The nitrogen-containing carbon source is used to form a carbon layer on the surface of silicon particles and realize nitrogen doping of the carbon layer and graphene, the preparation process is simple, controllable and environmentally-friendly, and the composite material greatly improves the integral electrochemical performances.

The invention discloses a preparation method of a hollow carbon material which has dodecahedron morphology and is doped with hollow cobalt phosphide nanoparticles in situ and an application of the hollow carbon material in catalytic electrolysis of water for hydrogen production, and belongs to the technical field of catalytic electrolysis of water for hydrogen production. The method comprises specific steps as follows: (1) preparation of a metal organic framework material ZIF-67 containing cobalt ions and having dodecahedral morphology; (2) the cobalt-containing metal organic framework material ZIF-67 and a dopamine monomer are subjected to reaction, and a cobalt coordination doped hollow polymer nano-material is generated; (3) a cobalt oxide/carbon composite hollow nano-material is prepared; (4) a hollow cobalt phosphide/carbon composite hollow nanomaterial is prepared. The size of the material can be adjusted according to size of ZIF-67; in performance tests of water for hydrogen production in catalytic electrolysis, the electrode material used as a cathode shows very good electrocatalytic activity and stability. Therefore, the material has very good application prospect as the electrode material for catalyzing electrolysis of water for hydrogen production.