120results about How to "Increase the number of active sites" patented technology

The invention relates to a carbon dioxide electrochemical reduction catalyst as well as a preparation method and an application thereof. The carbon dioxide electrochemical reduction catalyst comprises tin dioxide nanoflower, wherein the tin dioxide nanoflower is synthesized through hydrothermal reaction and comprises the synthesis raw materials including 0.1-0.5M of tin dioxide, 1-5M of trisodium citrate mixed solution and 0.1-0.5M of sodium hydroxide. The carbon dioxide electrochemical reduction catalyst is applied to a carbon dioxide electrochemical reduction catalyst gas diffusion electrode. The carbon dioxide electrochemical reduction catalyst has the advantages that the specific surface area of the catalyst is enlarged, the electrochemical reduction catalytic activity of the catalyst for carbon dioxide reduction is improved, the hydrogen evolution reaction is effectively inhibited, and the selectivity of formic acid in a product is improved.

The invention belongs to the technical field of electrocatalytic hydrogen evolution, and relates to a preparation method and application of a molybdenum disulfide / reduced graphene oxide-nitrogen carbide (MoS2 / rGO-CN) composite material. The preparation method comprises the steps of: firstly adding graphite oxide into deionized water, adding melamine into the obtained mixture, then performing ultrasound dissolution so as to form a colloidal solution, adopting a hydrothermal method to prepare aerogel of reduced graphene oxide-nitrogen carbide, and then performing a solvothermal reaction to obtain the target product by adopting ammonium tetrathiomolybdate as a molybdenum source and a sulfur source and N,N-dimethylformamide as a solvent. The preparation method of the aerogel of the reduced graphene oxide-nitrogen carbide is simple and high in yield, and since the MoS2 / rGO-CN is prepared by using the one-step solvothermal method, the preparation method has low cost and high repeatability and facilitates large-scale synthesis; by means of the prepared MoS2 / rGO-CN composite material, the accumulation of the molybdenum disulfide is reduced, and the quantity of active sites is increased; the conductivity and the active area of the MoS2 can be improved through the combination of the MoS2 with the rGO-CN, and when the prepared MoS2 / rGO-CN composite material is applied to an electrocatalytic hydrogen evolution reaction, excellent catalytic performance can be exhibited, and when the current density is 10 mA.cm<-2>, the overpotential is 203 mV, and the Tafel slope is 48 mV.dec<-1>.

The embodiment of the invention discloses a MoSxOy / carbon nanometer composite material, and a preparation method and application thereof, wherein in the MoSxOy / carbon nanometer composite material, x is greater than or equal to 2.5 but is smaller than or equal to 3.1; y is greater than or equal to 0.2 but is smaller than or equal to 0.7; on the basis of the total mass of the nanometer composite material, the mass percentage of the MoSxOy is 5 to 50 percent. When the prepared MoSxOy / carbon nanometer composite material is used as an electrocatalysis hydrogen evolution reaction catalyst, the current density during the overpotential of 300mV is equal to or higher than 150 mA / cm<2>; the performance has small differences from a commercial 20-percent Pt / C catalyst, or is even identical to that of the commercial 20-percent Pt / C catalyst. The performance is much better than that of the existing MoS2 composite material. In addition, the prepared MoSxOy / carbon nanometer composite material also has good catalysis stability; after the 8000 times of catalysis circulation, the current density is only lowered by 3 percent; excellent catalysis performance and circulation stability are shown.

The invention relates to an electrode for electroreduction of carbon dioxide. The electrode for electroreduction of carbon dioxide is composed of three layers with different functions and formed by successively laminating a substrate layer, an inner CO2 adsorption layer on the substrate layer and an outer catalysis layer, wherein the catalysis layer is composed of a catalyst and a proton conduction agent. According to the electrode in the invention, the concentration of carbon dioxide in the electrode is increased and mass transfer resistance is reduced in virtue of the adsorption layer; a metallic macrocyclic compound is grafted to and defined in a heteroatom-doped carbon nanotube, so the activity of the heteroatom-doped carbon nanotube used as the catalyst is improved; and introduction of the metallic macrocyclic compound further increases the amount of active sites of heteroatom-doped carbon, so the catalytic activity of the catalyst is improved. A preparation process for the electrode is simple and can be easily implemented.

The invention discloses a molybdenum doped vanadium disulfide micron flower material and a preparation method and application thereof. The molybdenum doped vanadium disulfide micro flower material iscomposed of molybdenum doped vanadium disulfide nanosheets by self-assembly. The preparation method comprises the steps of adding a vanadium source, a molybdenum source and ammonia water to water, stirring until being transparent, adding a sulfur source, and stirring to obtain a mixture; making the mixture be further subjected to an one-step hydrothermal reaction, and washing and drying a reactionproduct to obtain the molybdenum doped vanadium disulfide micron flower material; the preparation method has the advantages of simple process, low cost, high yield, mild condition, simple required equipment and environmentally friendly performance, and is capable of mass production. The application of the molybdenum doped vanadium disulfide micron flower material in an electrocatalytic hydrogen evolution reaction shows the excellent catalytic activity, the overpotential is as low as 0.243V (relative to a standard hydrogen electrode), and the Tafel slope is as low as 52.6mV / Dec.

The invention belongs to the technical field of electrochemical catalysis, and particularly relates to a platinum-based catalyst as well as a preparation method and application thereof. The platinum-based catalyst comprises a nitrogen-containing carbon carrier and platinum atoms loaded on the nitrogen-containing carbon carrier, and belongs to a loaded catalyst. The nitrogen-containing carbon carrier has good electrical conductivity, so the high-content nitrogen element is doped, the adsorption, the coordination and the anchoring of platinum atoms are easily achieved, the platinum atoms are uniformly distributed on the nitrogen-containing carbon carrier in a single atom state, the high dispersibility is provided, the agglomeration phenomenon cannot be generated, the platinum utilization rate in the platinum-based catalyst can be improved during the catalysis process, the platinum loading capacity is reduced, and the obtained platinum-based catalyst has advantages of low platinum and high efficiency. Meanwhile, the platinum-based catalyst disclosed by the invention has dual activities of catalyzing hydrogen evolution and hydrogen oxidation, and has a good application prospect.

The invention discloses an oxygen defect-rich ultrathin nickel cobalt oxide nanosheet electrode array catalyst. The catalyst is doped with silver, the catalyst structure is a nanosheet array structure, the thickness of the catalyst is 1-3 nanometers, and oxygen defect exists in a surface of the catalyst. The invention also discloses a preparation method and application of the catalyst. The catalyst is directly grown on a surface of formed nickel of a current collector in an in-situ way, the silver is doped into the catalyst, thus, the electrochemical specific area, the electrical conductivityand the electrocatalytic performance of the catalyst are improved; and meanwhile, after a catalyst precursor is thermally processed, thermal processing is further performed under an ammonia atmosphere, so that the oxygen defect is enriched in the surface of the catalyst, the numbers of exposed active sites are increased, the oxygen evolution and the oxidization-reduction reaction catalytic activity of the catalyst are remarkably improved, the catalyst is used in a rechargeable zinc-air battery, and high battery efficiency and cycle stability are shown.

The invention discloses a high-dispersity cobalt-based Fischer-Tropsch synthesis catalyst as well as a preparation method and an application thereof. The catalyst comprises an oxide carrier, wherein an active component cobalt and a noble metal addition agent are loaded on the surface of the oxide carrier; the active component cobalt accounts for 3%-40% of the total weight of the catalyst, the noble metal addition agent accounts for 0.01%-1% of the total weight of the catalyst and the oxide carrier accounts for 59%-96.99% of the total weight of the catalyst; and the specific surface area of the catalyst is 20m<2> / g-300m<2> / g. According to the high-dispersity cobalt-based Fischer-Tropsch synthesis catalyst, a high-pH-value complexing metal salt carrier is selected to provide a metal element loading environment; hydrazine hydrate and a heavy metal salt are respectively used as a reducing agent and an induction agent of a reduction reaction; the active component cobalt is obtained by reduction at low temperature, and a water-phase reaction environment and ultrasonic vibration are additionally adopted so that the dispersity and the reduction degree of active grains are improved; the reduction of the mechanical intensity of the carrier and the loss of the active component are effectively avoided; the service life is prolonged; and the catalyst can be directly used for a Fischer-Tropsch synthesis reaction without high-temperature roasting and activation reduction.

The invention provides a regeneration and reactivation method of a coal liquefied oil hydrogenation deactivated catalyst, which comprises the following steps: a) preparing an impregnating solution from a silicon-containing additive and deionized water, or from deionized water and an organic alcohol mixture in proportion, wherein the silicon-containing additive component in the impregnating solution accounts for 0.04-0.5 wt% of the total weight of the prepared solution; b) mixing the impregnating solution prepared in step a) with the regenerated hydrogenation catalyst, impregnating the regenerated hydrogenation catalyst at a first predetermined temperature and pressure for first predetermined time, wherein the silicon-containing additive component in the impregnating solution, when converted into the Si content, accounts for 0.03-0.5 wt% of the regenerated hydrogenation catalyst to be reactivated; c) drying the hydrogenation catalyst impregnated in step b) at a second predetermined temperature and pressure for second predetermined time, optionally, continuing drying at a third predetermined temperature and pressure for third predetermined time; d) roasting the impregnated hydrogenation catalyst dried in step c) at a fourth predetermined temperature for fourth predetermined time to obtain the reactivated hydrogenation catalyst.

The invention relates to a molybdenum selenide nanosheet / nitrogen-doped carbon core-shell-structure composite material which is of a hollow structure. A molybdenum selenide nanosheet serves as a core,and a nitrogen-doped carbon layer of a hollow nanobelt structure serves as a shell. A preparation method of the composite material includes: synthesizing a molybdenum trioxide nanobelt; synthesizinga molybdenum trioxide / polypyrrole binary composite material; synthesizing a molybdenum selenide / polypyrrole core-shell-structure binary composite material; synthesizing the molybdenum selenide nanosheet / nitrogen-doped carbon core-shell-structure composite material. The composite material can be used as a visible light catalyst, an electrocatalyst, a nano / lithium ion anode material and a light-emitting transistor material. The composite material overcomes the defect that a molybdenum selenide body material is low in activity, and instability of molybdenum selenide due to size expansion when inuse is relieved effectively. The preparation method is simple, easy to operate, environment-friendly, low in cost and suitable for industrial production.

The invention discloses a preparation method of an aluminum-doped nickel sulfide nano-flower material. The method comprises the following steps: (1) after mixing soluble nickel salt, soluble aluminum salt and an alkaline precipitant in a specific solvent, enabling the materials to react sufficiently by utilizing a hydrothermal method; washing and drying to obtain an alkaline carbonate precursor; (2) dispersing the precursor and a sulfur-containing compound into a water solution and carrying out hydrothermal reaction; washing and drying to obtain aluminum-doped nickel sulfide nano-flowers. A preparation method of an aluminum-doped nickel sulfide nano-flower electrode, provided by the invention, has a moderate process and raw materials are cheap; compared with an electrode made of a traditional nickel sulfide material, the capacitance characteristics and cycling stability of the aluminum-doped nickel sulfide nano-flower electrode are remarkably improved.

The invention provides a synthesis method of a metal nanoparticle asymmetrical single-face inlayed molybdenum disulfide nanosheet. The synthesis method comprises the following steps that 1, a metal salt powder material and molybdenum disulfide powder material are fully grinded and mixed according to the mass ratio of 1:3 to 1:50; 2, the mixed powder is put in flowing air for calcination, metal salt is decomposed to generate metal nanoparticles, the metal nanoparticles are inlayed on a molybdenum disulfide surface, and natural cooling is performed to obtain a complex; 3, the complex is dissolved in a solvent, and a molybdenum disulfide stratified material is stripped under the ultrasonic effect of a water bath, then the complex is centrifuged to obtain supernatant liquid, the supernatant liquid is centrifugally separated to obtain the metal nanoparticle inlayed molybdenum disulfide nanosheet. The molybdenum disulfide nanosheet is inlayed with the metal nanoparticles on one single face, the metal nanoparticles are narrower and adjustable in size distribution, accordingly the band gap of molybdenum disulfide is adjustable and controllable, the symmetry of molybdenum disulfide is destroyed, accordingly its electronic structure is changed, and meanwhile the number of active sites is increased.

The invention relates to a synthesis method of a mesoporous carbon nanosphere loaded manganous oxide material, and relates to the technical field of preparation of a nanometer material. Water, a hydrochloric acid solution, aniline and silicon dioxide sol are subjected to ultrasonic mixing and are then mixed with ammonium persulfate for reaction; aniline coated silicon dioxide is obtained; through the mixing reaction with a sodium hydroxide water solution, mesoporous polyaniline is obtained; then, under the ultrasonic condition, the mesoporous polyaniline with the pH value being 1 to 2 reacts with a potassium permanganate water solution under the stirring condition to obtain aniline loaded manganese dioxide; under the nitrogen gas protection, 900 DEG C calcination is performed to obtain the mesoporous carbon nanosphere loaded manganous oxide material. The synthesis method has the advantages that the method is simple and convenient; the preparation cost is low; the product has the good appearance features and also has high oxygen reduction catalysis activity; the important application values are realized in the fields of catalysis and the like.

The invention discloses a composite iron-carbon filler based on sludge iron-rich biochar as well as preparation and application thereof, and belongs to the technical field of pollutant degradation. The method comprises the following steps: dewatering sludge to obtain a mud cake, then adding an iron source, and pyrolyzing to obtain biochar with an iron-loaded carbon skeleton; then adding a binder to form a granular composite iron-carbon filler intermediate product; and roasting to obtain the porous composite iron-carbon filler. According to the preparation process, an iron phase with reaction activity is uniformly distributed on a sludge biological carbon skeleton, the carbon skeleton can play a role of an electron transmission channel and has a certain oxidation-reduction characteristic, and compared with a traditional iron-carbon composite material, the iron-carbon composite material has a better degradation effect on pollutants in landfill leachate.

The invention provides a catalytic purification composite material and a preparation method and application thereof. Activated carbon loaded manganese sand particles are used as a basic framework of the material, and mixed metal oxides as active components are loaded on the outermost layer of the framework. The preparation method of the material comprises the following steps: pretreating manganese sand and removing impurities on the surface of the manganese sand; taking wooden activated carbon or shell activated carbon as an activated carbon precursor; roasting in an inert atmosphere; preparing a porous carbon structure which uses the manganese sand as a framework; and modifying the surface of the manganese sand-porous carbon structure by using the metal oxides to form the novel composite purification material with adsorption and electro-catalyst composite functions. When the catalytic purification composite material is used, the composite material effectively adsorbs and catches low-concentration organic matters in micro-polluted raw water at first, so that pollutants are adsorbed on the surface of the material, then the composite material with adsorption saturation is guided into an electrolytic bath for electrochemical oxidation, the pollutants on the surface of the composite material are desorbed and decomposed, and are thoroughly mineralized into carbon dioxide and water, and meanwhile, recycling of the composite material is realized.

The invention discloses a silver ion doped zinc thioindate heterojunction photocatalyst preparation method, and relates to a catalyst preparation method, which comprises: carrying out a reaction on silver nitrate, zinc acetate, indium acetate, thioacetamide and indium oxide according to a certain ratio under an oil bath heating condition to obtain a target photocatalyst. According to the invention, the novel visible light photocatalyst is clear in structure and definite in composition; by doping with Ag<+>, the photon utilization rate of ZnIn2S4 can be remarkably increased; by compounding withIn2O3, the diffusion range of photon-generated carriers can be enlarged, the electron-hole pair is effectively separated, the recombination of photo-induced electron-hole pairs is inhibited, and theutilization rate of photo-induced electrons is greatly increased, so that the catalytic activity of visible light is enhanced; and the Ag:ZnIn2S4 / In2O3 composite material has high visible light activity, good hydrogen production capacity and good photocatalytic stability, so that the Ag:ZnIn2S4 / In2O3 composite material has wide prospect in the field of clean energy production and energy conversion, and is a catalyst with good development prospect.

The invention provides a carbon supported transition metal atom pair electrocatalyst and a preparation method and application thereof and belongs to the technical field of electrocatalysts. A nitrogen-containing carbon source is used as a carbon source and a nitrogen source, a catalyst precursor with uniformly dispersed transition metal diatom pairs on a carbon substrate is formed through precipitation reaction due to the complexation between transition metal ions and the nitrogen-containing carbon source, and the catalyst precursor is pyrolyzed and annealed in a protective atmosphere of 500-1000 DEG C so that the transition metal diatom pairs are dispersed on a porous carbon material to obtain the electrocatalyst. The double transition metal atoms are introduced, so that the number of active sites of the electrocatalyst can be increased, the activity and the oxygen reduction activity of the electrocatalyst can be effectively improved, and the electrocatalyst has wide application prospect in the fields of metal air batteries and fuel cells. In addition, the preparation method is simple, the price of the required raw materials is low, the equipment is simple, and large-scale industrial production is easy to achieve.

The invention discloses a cerium oxide supported bismuth nano catalyst as well as a preparation method and application thereof and belongs to the fields of catalyst techniques and sustainable development of energy. The preparation method comprises the following steps: by using a one-step reduction method, preparing a carrier cerium oxide at the room temperature; and mixing the carrier cerium oxidewith Bi(NO3)3*5H2O, and performing steps of centrifugation, drying and calcining, so as to obtain the cerium oxide supported bismuth nano catalyst. According to the cerium oxide supported bismuth nano catalyst, massive pores inside cerium oxide are sufficiently utilized and combined with bismuth nanoparticles, so that the number of active sites can be increased, and the activity of the catalyst can be remarkably improved. Particularly, in formic acid production from CO2 through electrochemical reaction, the cerium oxide supported bismuth nano catalyst has very good catalysis activity and excellent stability.

The invention discloses a preparation method of a hydrotreating catalyst. The preparation method comprises the following steps: (1) preparing an impregnating solution containing group-VIII metals, group-VIB metals and 2-amino-1,3 propylene glycol, wherein the molar ratio of 2-amino-1,3 propylene glycol in the impregnating solution to group-VIII metal atoms contained in a final catalyst is 0.1:1 to 2:1; (2) impregnating an aluminum oxide carrier by adopting the impregnating solution prepared in the step (1) and firstly treating for 2-60 minutes under the condition that the microwave power is 2-20 W / g after the end of impregnation; then drying to prepare the hydrotreating catalyst. The catalyst prepared by the preparation method disclosed by the invention is easy to fully vulcanize; more Class-II active centers are generated, so that the effective utilization rate of active components is increased, and the activity of the catalyst is improved.

Preparation of a nickel-calcium-based composite catalyst and its application in the biomass catalytic pyrolysis process are disclosed. The preparation comprises the following steps: preparing a layered metal hydroxide precursor; and calcinating and reducing to obtain a Ni-Ca-based composite catalyst orderly assembled by nano-particles or nanosheet structural units. The application of the catalystin the biomass catalytic pyrolysis process comprises the following steps: tabletting the prepared Ni-Ca-based composite catalyst, crushing and sieving to obtain a catalyst powder with the granularitybeing 20-80 meshes; filling a fixed bed first-order reactor with a biomass material, filling a second-order reactor with the above prepared catalyst with the particle size being 20-80 meshes, introducing N2 to discharge the air in the reactors, simultaneously heating the reactors to a set temperature, letting pyrolysis steam generated by pyrolysis of the biomass material crack and reform on the surface of the Ni-Ca-based composite catalyst to obtain cracking steam, condensing the cracking steam and then drying to obtain gaseous and liquid products.

A subgroup VI element to prepare a catalyst for the production of organic chemicals and fuels from lignin with the involvement of solvent molecules. The catalytic reaction use a catalyst composed of a molybdenum or tungsten compound as the active phase, with mixing a kind of lignin, a catalyst, and a reactive solvent. An inert or reductive gas such as H2, N2 or Ar is used to purge or fill the reaction vessel. The temperature is above 200° C., the reaction time is sufficient. The liquid product is separated and analyzed; a catalytic process with a very high product yield, up to 90% if calculated accounting the parts from lignin of the product molecules, or up to over 100% if calculated as the mass products. The product includes aromatic compounds, esters, alcohols, monophenols and benzyl alcohols in different ratios according to the composition, the solvent and the other reaction conditions.

A method for prepare a nitrogen-doped carbon microsphere / Pd composite catalyst comprises: adding carbon material into nitric acid solution, stirring, heating, heat preservation, cooling, filtering anddrying; (2) calcining the carbon material prepared in the step (1) at a temperature of 300-1000 DEG C under a protective gas atmosphere to obtain a black powder material; (3) mixing the black powdermaterial, water, ammonium sulfate, ammonium persulfate, and palladium nitrate obtained in the step (3) to prepare an aqueous solution, stirring, heating and keeping temperature, cooling, filtering, and drying. As that catalyst in the present application has high catalytic activity and good stability for oxygen reduction, the method is simple.

The invention belongs to the field of irreversible hydrogen storage materials, and discloses a fine regulation supported alloy catalyst and a preparation method and application thereof. The catalyst comprises a metal alloy active phase and a metal oxide matrix phase, wherein the metal alloy active phase is highly dispersed on the surface of the metal oxide matrix phase in the form of ultra-small nanoparticles. The preparation method comprises the following steps: adjusting the pH values of solutions of different precious metal precursor salts according to needs, adsorbing a single layer of theprecious metal precursor salts on a solid solution substrate, and carrying out a heat treatment reaction on the obtained product in a reducing atmosphere to obtain the high-dispersion nano-alloy catalyst. The preparation method has the advantages of easily available raw materials, simple process and easiness in mass production. The prepared catalyst has high intrinsic catalytic activity, rich active sites and excellent stability, and can efficiently catalyze hydrazine hydrate to decompose to produce hydrogen under alkaline conditions.

The invention discloses a nano-porous Fe-P-C material and a preparation method thereof, and applications in hydrogen production through water electrolysis, wherein a crystal strip of an alloy is prepared from the following components in percentage by mass: 22-64% of pure Fe, 19-41% of Fe3P and 17-37% of Fe3C. The preparation method comprises: carrying out mixing smelting on metal raw materials toobtain an alloy ingot, melting the alloy ingot, spraying out to obtain an alloy strip, and carrying out ultrasonic vacuum drying. According to the invention, a three-electrode system of an electrochemical workstation is used, a calomel electrode is used as a reference electrode, a platinum net is used as a counter electrode, a Fe-P-C alloy strip is used as a working electrode, an H2SO4 aqueous solution is used as an electrolytic solution, electrochemical corrosion is carried out through constant potential, the potential parameter is -0.1 V to -0.5 V, and the corrosion time is 600-1600 s. Compared with the noble metal catalysts on the market, the ano-porous Fe-P-C material of the invention has characteristics of high price advantage, high stability, simple preparation method, few process and good market industrialization prospect.

The invention discloses a hydrocracking catalyst and a preparation method thereof. The hydrocracking catalyst includes an active component and a carrier, wherein the active component is NiO and WO3 and the carrier is a composite carrier of AlOOH and TiO2; an additive contains phosphorus; the catalyst is prepared through a complete liquid-phase process. In the invention, when the hydrocracking catalyst is used for hydrocracking of medium / low-temperature coal tar, conversion to light fraction is greatly improved on the basis of guaranteeing high liquid yield, wherein H / C molar ratio of the coaltar is increased from 1.153 to more than 1.556 (fuel oil), even to 1.603 when the catalyst is optimized. The hydrocracking catalyst solves difficult problems that a fixed bed catalyst in the prior artis difficult to industrialize due to surface coking and inactivation caused by non-uniform heat distribution in a bed layer; the preparation method has simple process and simple operations.

The invention provides an electrocatalyst for sulfur-nitrogen-transition metal co-doped carbon-based oxygen reduction. The C:N:S:O:M mass ratio is 50-80:2-15:0.1-6:3-20:0.01-8, where M represents a transition metal, and the specific surface area of the catalyst is 450-1900 m2 / g. The electrocatalyst provided by the invention has the advantages of good electrocatalytic performance and stability of cathode oxygen reduction under both acidic and basic conditions.

The invention discloses a cobalt-nickel bimetal phosphate flower-like microsphere electrocatalyst and a preparation method thereof. The preparation method comprises the steps of adjusting PH with urea, and slowly synthesizing cobalt-nickel bimetal organic phosphoric compound flower-like microsphere precursor CoNiPP; carrying out high temperature treatment at different temperatures to obtain the cobalt-nickel bimetal phosphate flower-like microsphere electrocatalyst which still well retains the flower-like microsphere structure of the precursor and which has a structural general formula of CoNiPP-T, with T=700-900 DEG C. The flower-like microsphere structure helps effectively increase specific surface area and porosity of a material, thereby adding more transfer channels of internal electrons during electrocatalytic reaction; organic benzene rings in phenylphosphonic acid are removed and decomposed by calcining to obtain a porous carbon coating layer, so that the quantity of active sites for electrocatalytic reaction can be increased. In addition, double metals are present, each metal corresponds to a different active site, and therefore, the quantity of active sites for electrocatalytic reaction can also be increased.

The invention belongs to the technical field of porous catalyst preparation, and particularly relates to a hierarchical porous composite metal oxide as well as a preparation method and application thereof. The micropore volume of the hierarchical porous composite metal oxide disclosed by the invention is 0.036 to 0.058 cm < 3 > / g; the pore volume of mesopores is 0.106 to 0.196 cm < 3 > / g; the pore volume of a macropore is 0.010 to 0.310 cm < 3 > / g; and the hierarchical porous composite metal oxide has a structure as shown in M1M2Ox, wherein M1 and M2 comprise any two of Mn, Cu, Fe and Ce. The hierarchical porous composite metal oxide provided by the invention has a hierarchical porous structure, so that the contactable specific surface area of the hierarchical porous composite metal oxide is increased, and the catalytic activity of the hierarchical porous composite metal oxide is enhanced by increasing the number of active sites and the adsorption efficiency of reactants.

The invention relates to a modified hydrotalcite-like derived cobalt catalyst, general formula being M / M1(O)-M2(O)-M3(O), wherein M represents Co, M1 represents an alkaline earth metal, M2 representsa rare earth metal, M3 represents Al, n(Co+M1) / n (Al+M2)=2-4, the molar ratio of Co to M1 is 0.5-1.5, and the molar ratio of M2 to Al is 0.005-0.05. The preparation method comprises the following steps: dissolving various metal salts and urea in water to form an aqueous solution, crystallizing the aqueous solution to obtain a solid-liquid mixture, filtering the solid-liquid mixture, respectively washing with water and a modifier, dispersing the mixture in the modifier, carrying out ultrasonic treatment, and filtering and drying the product to obtain a modified hydrotalcite-like precursor; androasting and reducing the precursor to obtain the catalyst. The catalyst is used for synthesizing cyclohexylamine through aniline hydrogenation, the aniline conversion rate can reach 98% or above, andthe dicyclohexylamine selectivity is 3% or below.

The invention discloses a preparation method for molybdenum disulfide-sepiolite nanofiber composite materials, and relates to composite materials. The preparation method based on a microwave hydrothermal process includes preparing a reactant stock mixed liquor of molybdate, sulfides and sepiolite nanofibers; pouring the reactant stock mixed liquor into a polytetrafluoroethylene reaction kettle, and putting the reaction kettle in microwave hydrothermal equipment to complete microwave-hydrothermal-process based effective compounding of reactants; cleaning and drying products obtained by the microwave hydrothermal process to obtain the molybdenum disulfide-sepiolite nanofiber composite materials. The preparation method has the advantages that the defects of the prior art for preparing molybdenum disulfide composite materials, including proneness to re-gathering or stacking of the molybdenum disulfide composite materials during drying or annealing, complexity in preparation process, long reaction period, high energy consumption and high cost, are overcome.