201 results about "Mesoporous carbon" patented technology

A method of mesoporous carbon support production includes providing an active silica template from a self-assembling block copolymer (BCP) in a solution, the BCP including a diblock copolymer of polydimethylsiloxane (PDMS) as a majority block and a hydrocarbon polymer as a minority block in a predetermined volume fraction, the BCP being in a form of nanodroplets, drying and annealing the nanodroplets, ashing away the hydrocarbon polymer of the minority block to obtain the active silica template, applying a carbon precursor onto the active silica template, and removing the active silica template to obtain a mesoporous carbon support as a reverse image of the template.

Herein is described a composite material, the composite material comprising composite 5 particles comprising particles of a mesoporous carbon support material having dispersed on their surfaces noble metal nanoparticles and / or noble metal-M alloy nanoparticles and optionally particles of the elemental metal M or metal oxide MOy, wherein y is >0 to a stoichiometric value of the metal oxide, wherein M is a less noble metal than the noble metal, wherein the composite particles have a BJH average pore diameter of from 2 to 0 50 nm and a particle size D90, as measured by laser diffraction and volume distribution, of 10 µm or less.

The invention relates to a uniform carbon-coated mesoporous silicon carbon negative electrode material and a preparation method and application thereof.The preparation method comprises the steps that a product obtained after pyrolysis and carbonization of a biomass carbon source is subjected to alkali activation treatment, acid pickling, drying, smashing, passivation, water washing and drying are conducted to obtain a mesoporous carbon matrix, nanometer silicon particles are deposited in pores of the mesoporous carbon matrix, and the uniform carbon-coated mesoporous silicon carbon negative electrode material is obtained. Then selecting a low-temperature carbonization material and polyethylene glycol to perform pre-carbonization and complete carbonization treatment on the mesoporous silicon carbon material to obtain a carbon coating layer, and finally obtaining the uniform carbon-coated mesoporous silicon carbon negative electrode material. When the uniform carbon-coated mesoporous silicon carbon negative electrode material is applied to a lithium battery, the mesoporous skeleton can effectively inhibit volume expansion of silicon in a battery circulation process, and the uniform carbon-coated layer can effectively reduce the risk of direct contact between the negative electrode material and an electrolyte, so that a stable SE I film is formed to reduce the occurrence of side reactions; and the first coulombic efficiency and the cycle performance of the battery are further improved.

The invention relates to the technical field of carbon material preparation, and discloses a dispersed metal monatomic nitrogen-doped spherical mesoporous carbon material and a preparation method thereof, and the preparation method comprises the following steps: introducing a vinyl-containing metal precursor in a prepolymer stage, and grafting a metal center to a polymer skeleton in situ through chemical bonding; then preparing phenolic resin balls by using the amphiphilic block copolymer as a soft template and combining an emulsification curing process; and finally, carbonizing the resin balls, and introducing water vapor with a specific proportion for activation to construct mesoporous and microporous graded channels. According to the invention, agglomeration of metal atoms at a high temperature is effectively inhibited through in-situ chemical bonding, and high-dispersion loading of single atoms is realized; meanwhile, the soft template and water vapor activation have a synergistic effect, so that the material is endowed with a high specific surface area and a developed hierarchical pore structure. When the obtained material is used as a supercapacitor electrode, high specific capacitance, excellent rate capability and good cycling stability are shown.

The invention relates to the technical field of battery silicon negative electrodes, in particular to a silicon-carbon composite material and a preparation method and application thereof. The silicon-carbon composite material comprises a three-dimensional through mesoporous carbon skeleton, nano silicon particles loaded in mesopores and a gradient carbon coating layer, nano silicon and the carbon skeleton are connected through Si-O-C covalent bonds, and the gradient carbon coating layer is composed of a soft carbon inner layer, a graphitized carbon middle layer and a compact hard carbon outer layer. The preparation method comprises three steps of synthesis of a three-dimensional through mesoporous carbon skeleton, confinement silicon loading and gradient carbon coating. The material solves the problems of silicon particle agglomeration, volume effect and interface instability, has excellent electrochemical performance, can be used as a lithium ion battery negative electrode material, is suitable for a next-generation high-energy lithium ion battery, and improves the cycling stability and capacity performance of the battery.

An actuator includes a twisted and coiled polymer fishing line and an untwisted resistance heating wire (TCPFLRHW) actuator and a coating on the TCPFLHRW actuator. The coating includes a mixture of carbon nanotubes, metal nanoparticles, and mesoporous carbon nanoparticles, and in some variations, the coating includes a polymer matrix with the carbon nanotubes, metal nanoparticles, and mesoporous carbon nanoparticles disposed in the polymer matrix. And the actuator exhibits enhanced actuator parameters such as actuator efficiency, hydrophobicity, power consumption, actuation frequency, dynamic actuation and cooling rate.

This invention belongs to the field of electrocatalytic hydrogen evolution catalyst technology, and particularly relates to an ultrasmall intermetallic compound confined in mesoporous carbon interstices and its preparation method. Using mesoporous silica SBA-15 as a hard template, sulfur-containing amino acids are filled into the SBA-15 channels via capillary action as a carbon source. Simultaneously, potassium chloroplatinate and a transition metal source are also filled into the SBA-15 channels along with the sulfur-containing amino acids. The mass ratio of potassium chloroplatinate, SBA-15, and sulfur-containing amino acids is 1:5–10:20–30, and the metal mass is consistent with the atomic ratio in the formed Pt-based intermetallic compound. The reaction also includes a solvent and water. This invention uses electrocatalytic hydrogen evolution as a model reaction to investigate the catalytic activity and stability of this PtFe ultrasmall nanoparticle embedded in a mesoporous carbon support. Electrocatalytic results show that it exhibits excellent activity and stability, meeting the requirements of related applications and development.

The application discloses a mesoporous carbon preparation process with recyclable silicon source and mesoporous carbon with small pore size and large specific surface area. The mesoporous carbon preparation process comprises the following steps: preparing a silicon template: reacting a fluosilicic acid solution with calcium carbonate, and separating calcium fluoride precipitate and silica sol; the pH of the silica sol is 2-5; the concentration of silicon dioxide in the silica sol is 1-8 wt%; preparing a precursor: dissolving a carbon source and an organic acid in the silica sol, drying, grinding, and carbonizing in an inert atmosphere to obtain a C / Si precursor; the organic acid comprises at least one of oxalic acid, tannic acid, acetic acid and citric acid; removing the silicon template and recycling the silicon source: treating the C / Si precursor with hydrofluoric acid, and performing solid-liquid separation to obtain mesoporous carbon and a fluosilicic acid solution, wherein the fluosilicic acid solution is used for preparing the silicon template. The specific surface area of the mesoporous carbon is greater than 800 m 2 / g, and the pore size is less than 6 nm.

This invention discloses a sol-gel preparation method for mesoporous carbon membranes, as well as the mesoporous carbon membranes and their applications. The preparation method includes: (1) dissolving phenolic compounds in a solvent and adding a template agent; (2) adding aldehyde compounds and amine compounds to obtain a mixture; (3) subjecting the mixture to a hydrothermal reaction to obtain an organic membrane precursor; and (4) carbonizing the organic membrane precursor at high temperature; wherein the solid content of the mixture is 20-30 wt%. The method of this invention significantly shortens the production cycle, has high preparation efficiency and success rate, can be molded to any size, and the obtained porous structure can withstand high-temperature treatment without collapsing. The obtained mesoporous carbon membrane can be applied to gas separation or liquid separation.

This invention discloses a method for preparing a Pd-BiOI / ordered mesoporous carbon electrode, comprising: step S1, preparing an ordered mesoporous carbon electrode material using a soft template method under low-temperature hydrothermal conditions; step S2, using a three-electrode system, with the ordered mesoporous carbon electrode material as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode, using a hydrochloric acid solution containing PdCl2 as the electrolyte, and depositing a Pd / OMCs electrode using a multi-step current pulse method; step S3, adding KI to ethylene glycol and dissolving it by magnetic stirring; then adding Bi(NO3)3•5H2O and stirring magnetically to obtain a mixture a; placing the mixture a and the Pd / OMCs electrode prepared in step S2 in a high-pressure reactor lined with polytetrafluoroethylene, and performing a hydrothermal reaction under high-temperature conditions, followed by rapid cooling after the reaction, removing the electrode and rinsing it with distilled water to obtain the Pd-BiOI / OMCs electrode. The Pd-BiOI / ordered mesoporous carbon electrode prepared by this invention has both excellent electroadsorption and visible light photocatalytic performance, and is expected to become an ideal electrode material integrating electroadsorption and photocatalysis.

The application belongs to the technical field of electromagnetic wave absorbing materials, and particularly relates to a co-doped mesoporous carbon sphere wave absorbing material, a preparation method and an application. The preparation method comprises the following steps: aniline is added into a colloidal silica hydrochloric acid solution and uniformly mixed to obtain a mixed solution; then, ammonium persulfate hydrochloric acid solution is added into the mixed solution and uniformly mixed; drying is performed to obtain a precursor; the precursor is calcined under a protective atmosphere to obtain an intermediate; then, the intermediate and a sodium hydroxide solution are mixed, heated, and treated to obtain the co-doped mesoporous carbon sphere wave absorbing material. The calcination method comprises the following steps: the precursor is heated to 250-350 DEG C under a protective atmosphere and then heated to 700-900 DEG C for calcination. The co-doped mesoporous carbon sphere wave absorbing material has excellent wave absorbing performance.

The present application relates to a kind of mesoporous carbon supported heteroatom doped metal catalyst and its preparation method.The preparation method described in the present application.The present application provides a kind of ligand-induced crystallization-mesoporous confined pyrolysis strategy preparation mesoporous carbon supported heteroatom doped metal catalyst, this method includes the metal precursor is formed MOF or metal organic salt by ligand-induced crystallization in the mesoporous of carbon carrier, and two processes of mesoporous confined pyrolysis.The method provided in the present application solves the problems of yield, mass transfer and stability of traditional heteroatom doped carbon supported metal catalyst.

This invention relates to the field of electro-digital data processing technology, specifically to a method and system for monitoring the dispersion state of mesoporous carbon electrode slurry based on data fusion. The method includes: performing Granger causality tests on time-series monitoring data to identify target sensor pairs and their causal directions, determining the causal and consequential sensors; performing multi-scale decomposition; performing cross-scale correspondence analysis to determine the cross-scale correspondence layer; setting a prediction window and verifying cross-scale response during real-time monitoring; and calculating the dispersion state index of the mesoporous carbon electrode slurry. This invention establishes a causal correlation and transfer parameter model between monitoring data at the micro-particle scale and macro-flow behavior scale of mesoporous carbon electrode slurry through the coupling of Granger causality tests and multi-scale decomposition, enabling the dispersion state assessment to reflect cross-scale dynamic evolution rather than local information at a single scale.

The present disclosure relates to the technical field of electrode materials, and in particular to a porous carbon, a silicon-carbon negative electrode material, an electrode sheet, a lithium-ion battery, and an electric device. The porous carbon has micropores and mesopores, wherein pores with a pore size of less than 3 nm account for more than 85% of the total pore volume, and pores with a pore size of less than 0.7 nm account for less than 15% of the total pore volume; and the porous carbon exhibits a Luan-type pore size distribution, wherein the Luan-type distribution is defined as: within a pore size range of 1-3 nm, a pore size distribution curve has a Dv / Dw value greater than 0.05 cm3·g-1·nm-1. The porous carbon provided in the present disclosure is a micro-mesoporous carbon, exhibits the Luan-type distribution, and has low pore resistance, thereby improving silicon loading efficiency, and ensuring intercalation and deintercalation of lithium ions while ensuring adsorption capacity. The silicon-carbon negative electrode material prepared by using the porous carbon exhibits high capacity and efficiency, and low expansion.

The present application relates to the field of battery, especially to a gradient pore hierarchical nitrogen-doped carbon-coated composite sodium supplement agent and its preparation method and application, comprising: a composite sodium supplement agent core and a coating layer coated on the surface of the composite sodium supplement agent core; wherein the composite sodium supplement agent core comprises: an inorganic sodium supplement phase and an organic sodium supplement phase; the coating layer comprises from inside to outside: an inner dense amorphous carbon layer, a middle mesoporous carbon layer and an outer macroporous carbon layer. The present application innovatively designs a gradient pore carbon coating structure from inside to outside, the inner dense amorphous carbon layer realizes efficient isolation protection, the middle mesoporous carbon layer solves the problem of ion transmission obstruction, and the outer macroporous carbon layer improves the electronic conduction and volume buffering capacity, completely solving the inherent contradiction between the denseness of the traditional carbon coating layer and ion transmission, realizing the synergy and unity of "isolation protection-ion transmission-electronic conduction".

The invention belongs to the technical field of fuel cell cathode oxygen reduction catalysts, and particularly relates to a high-dispersion platinum group metal-transition metal mesoporous carbon catalyst and a preparation method and application thereof. The high-dispersion platinum-cobalt alloy mesoporous carbon catalyst is prepared in an ammonia water dipping coprecipitation-confinement reduction mode, the problems that in a traditional platinum-cobalt mesoporous carbon catalyst, the utilization rate of precious metal is low, and stability is poor are solved, efficient catalysis of a fuel cell ORR is achieved, and the application prospect is wide. The prepared high-dispersion platinum-cobalt mesoporous carbon catalyst has an ECSA attenuation rate of less than 10% in a disc electrode three-electrode test after long circulation for 60k circles, and has a potential of 0.678 V and 1.356 W / cm < 2 > in a proton exchange membrane fuel cell (PEMFC) test when the current density is 2000mA / cm < 2 >.

The application discloses a synthesis method of pentachloropropane based on raw materials of vinyl chloride and carbon tetrachloride, and belongs to the technical field of new chemical materials. Main steps include raw material proportioning and pretreatment, nano-catalytic reaction, product initial extraction and purification, etc. The catalyst used is prepared by loading the composite of ferrous chloride and nano iron oxide on a mesoporous carbon carrier, and has excellent catalytic performance. The product is purified through vacuum distillation and an activated carbon adsorption column, and the purity can reach more than 99.7%. The method innovatively combines nano technology and specific reaction conditions, and has the advantages of high yield, high product purity and good catalyst stability. Compared with the traditional synthesis method, the technology significantly improves the production efficiency and reduces the energy consumption, provides an innovative and practical technical path for the industrial production of pentachloropropane, and has a wide application prospect.

An electrode material is provided that provides an electrode for a fuel cell with excellent electrode performance and durability. The electrode material is any one of the following electrode materials (A) or (B): Electrode material (A): comprising a porous composite support and electrode catalyst particles supported on the porous composite support, the porous composite support comprising: a carbon support composed of mesoporous carbon; and an electronically conductive oxide fixed to at least the inner surface and outer surface of the micropores of the mesoporous carbon, wherein a portion or all of the electrode catalyst particles are supported within the micropores of the mesoporous carbon via the electronically conductive oxide. Electrode material (B): comprising a carbon support composed of mesoporous carbon; and an electrode catalyst composite fixed to at least the inner surface and outer surface of the micropores of the mesoporous carbon, wherein the electrode catalyst composite comprises electrode catalyst particles and an electronically conductive oxide, the electronically conductive oxide being present in a manner that fills the spaces between the electrode catalyst particles.

The invention relates to the field of rubber additives, in particular to a lignin-based composition as well as a preparation method and application thereof. Aiming at the problem of blockage caused by adhesion of a rubber component to a container and equipment when lignin is used as a reinforcing agent in the prior art, the lignin-based composition provided by the invention comprises lignin and a porous material, the mass ratio of the lignin to the porous material is 1: (0.12-0.5); the porous material comprises one or more of porous starch, a porous carbon material, porous calcium carbonate and porous kaolin; the porous carbon material comprises one or more of activated carbon, carbon black, mesoporous carbon, carbon nanotubes, graphene aerogel and biomass carbon. The preparation method comprises the following steps: drying lignin, and mixing the dried lignin with the dispersing agent and the porous material to obtain the lignin-based composition. By adding the lignin, the dispersing agent and the porous material in a specific proportion, electrostatic adsorption of the lignin is reduced, and the problem that the rubber composition is easy to adhere to a container and equipment is solved.

This invention discloses a continuous silicon nanowire anode material based on ALD seed layer-induced mesoporous confinement and its preparation method. The material comprises a mesoporous carbon framework with interconnected pore structures, and a one-dimensional silicon nanostructure located within the pores and extending continuously along the axial direction. The one-dimensional silicon nanostructure is connected to the inner wall of the mesoporous carbon through an interface modification layer, forming a continuous electron / ion transport pathway. The interface modification layer is formed by in-situ transformation of a metal oxide seed layer deposited on the inner wall of the pores under a silicon source gas and a reducing atmosphere, and its composition includes elemental metals, metal-silicon alloy phases, or metal silicides. Utilizing the spatial confinement effect of the mesoporous carbon, the radial expansion of the silicon nanostructure is restricted within the pores, reducing mechanical compression on the solid electrolyte; simultaneously, during the delithiation shrinkage process, the axial connectivity of the silicon nanostructure is maintained, alleviating solid-solid interface contact degradation, thereby improving the cycle stability and rate performance of the all-solid-state battery.

The invention relates to the field of fine chemical engineering, in particular to a supported acid catalyst and a preparation method and application thereof. The catalyst comprises a carrier and an active component loaded on the carrier; wherein the carrier is a mesoporous carbon material, and the active component is lanthanum p-toluenesulfonate; on the basis of the total weight of the supported acidic catalyst, the content of the mesoporous carbon material is 25 to 55 weight percent, preferably 31 to 49 weight percent, more preferably 35 to 44 weight percent, and the content of the lanthanum p-toluenesulfonate is 45 to 75 weight percent, preferably 51 to 69 weight percent, and more preferably 56 to 65 weight percent. The supported acidic catalyst provided by the invention is stable in structure, good in high temperature resistance, non-toxic, free of deformation and swelling in the reaction process, easy to recover after the reaction, mild in process condition and low in requirement on a reaction device when being used for an oleate synthesis reaction. The oleic acid conversion rate is high and the oleate selectivity is high.

This invention discloses a mesoporous carbon composite material and its preparation method. The preparation method is as follows: S1: Using tetraethyl orthosilicate as the silicon source, an ethanol / deionized water mixture, a surfactant as the solvent system, and a conductive agent as the dopant, a polycondensation reaction is carried out under acid-base catalysis. A silica / soft template composite is formed through a sol-gel process, followed by high-temperature sintering to obtain a silica composite template; S2: A mixed solution A is prepared by mixing a phenol source, a dispersant, and water; a mixed solution B is prepared by mixing an aldehyde source, a lithium supplement, and a catalyst; S3: Mixed solutions A, B, and the silica composite template are reacted, carbonized, and activated. The resulting material is then added to a hydrofluoric acid solution to dissolve the template, and the resulting material undergoes thermal reduction to obtain the mesoporous carbon composite material. The mesoporous carbon prepared using the template method exhibits advantages such as high uniformity, large pore volume, and low powder resistivity. It can be applied to silicon-carbon composite materials to increase the deposition amount of nano-silicon, improve specific capacity, and reduce the expansion of silicon-carbon materials.

The invention relates to the technical field of inorganic mesoporous materials, in particular to an amplification preparation system of millimeter-scale mesoporous carbon spheres. The preparation method comprises the following steps: mixing a phenolic precursor aqueous solution, an aldehyde precursor aqueous solution and a silicon dioxide aqueous solution, and performing prepolymerization to obtain a prepolymer solution; dropwise adding the prepolymer solution into liquid paraffin oil, carrying out reversed-phase suspension polymerization reaction, and then carrying out aging treatment to obtain phenolic resin spheres; calcining the phenolic resin spheres in an inert atmosphere to obtain millimeter-scale carbon spheres; and carrying out etching treatment on the millimeter-level carbon spheres to obtain the millimeter-level mesoporous carbon spheres. The invention creatively provides a pre-polymerization-molding-aging combined system in the engineering mass production of the millimeter-scale mesoporous carbon spheres, determines an amplified preparation process, and defines the influence of process parameters on the product quality; the engineering synthesis steps of the millimeter-scale mesoporous carbon spheres are optimized, the synthesis uncertainty is reduced, the cost of raw materials is reduced, and the large-scale production is facilitated.

The invention relates to the technical field of grain and oil by-product high-value utilization and food functional ingredient preparation, in particular to a nitrogen-rich mesoporous carbon-based cholesterol adsorption ingredient as well as a preparation method and application thereof. According to the method, soybean meal and rice bran are taken as a carbon source and an endogenous nitrogen source, and urea or melamine is compounded as an exogenous nitrogen-rich precursor, so that an internal-external synergistic nitrogen-rich system is constructed; the method comprises the following steps: compounding a zinc chloride or potassium hydroxide chemical activator with a ferric chloride catalytic graphitizing agent to form a nitrogen-rich-catalytic synergistic conversion system; the method comprises the steps of raw material pretreatment, nitrogen-rich slurry preparation, catalytic activation precursor preparation and the like. The prepared carbon-based ingredient has a developed mesoporous structure and high-content alkaline nitrogen-containing functional groups, and is large in cholesterol adsorption capacity and high in selectivity, and the raw materials are grain and oil processing byproducts, so that the cost is low, and the carbon-based ingredient is green and environment-friendly; the preparation process has the advantages of controllable parameters and good repeatability, is suitable for industrial production, and provides a new technical path for the development of functional food ingredients for reducing blood fat.

The present invention addresses the problem of providing a carbon-supported platinum or platinum alloy catalyst for a solid polymer fuel cell, said catalyst having high activity and high durability. [Solution] A carbon-supported platinum or platinum alloy catalyst in which platinum particles or platinum alloy particles are supported on mesoporous carbon, the carbon-supported platinum or platinum alloy catalyst being characterized in that: the load rate of platinum or platinum alloy in the catalyst is 30-70% by weight of the total weight of the catalyst; relative to the total weight of the platinum particles or the platinum alloy particles, the total weight of the platinum particles or the platinum alloy particles loaded outside the pores of the mesoporous carbon is 60-90%; the average particle diameter D1 of the platinum particles or platinum alloy particles supported in the pores of the mesoporous carbon is the same as or greater than the average particle diameter D2 of the platinum particles or platinum alloy particles supported outside the pores of the mesoporous carbon, and the average particle diameter D1 and the average particle diameter D2 are each independently 2 nm or more and 8 nm or less.

The invention discloses a mesoporous carbon composite material and a preparation method thereof.The preparation method comprises the steps that S1, tetraethyl orthosilicate serves as a silicon source, an ethyl alcohol / deionized water mixed solution and a surfactant serve as a solvent system, a conductive agent serves as a doping agent, condensation polymerization is carried out under an acid-base catalyst, a silicon dioxide / soft template compound is formed through the sol-gel process, and the mesoporous carbon composite material is obtained; sintering at high temperature to obtain a silicon dioxide composite template; s2, mixing a phenol source, a dispersing agent and water to prepare a mixed solution A; mixing an aldehyde source, a lithium supplement agent and a catalyst to prepare a mixed solution B; s3, mixing the mixed solution A, the mixed solution B and the silicon dioxide composite template for reaction, carbonizing and activating, then adding the obtained material into a hydrofluoric acid solution to dissolve the template, and performing thermal reduction on the obtained material to obtain the mesoporous carbon composite material. Mesoporous carbon prepared from the obtained material by using a template method has the advantages of high consistency, large pore volume, low powder resistivity and the like, and is applied to a silicon-carbon composite material to improve the deposition amount of nano silicon, improve the specific capacity and reduce the expansion of the silicon-carbon material.

This invention provides a mesoporous carbon material, its preparation method, and its applications. The preparation method includes the following steps: mixing a carbon source, a solvent, and a surfactant to obtain a slurry with a viscosity of 2.98 × 10⁻³ Pa·s to 20 Pa·s; subjecting the slurry to evaporation-induced self-assembly to obtain a mesoporous carbon precursor material; and extracting and carbonizing the mesoporous carbon precursor material with the surfactant to obtain the mesoporous carbon material. The preparation method provided by this invention, through the synergistic combination of a high-viscosity slurry and a surfactant extraction scheme, enables the large-scale production of mesoporous carbon materials prepared by the EISA method, while also effectively recovering the surfactant, avoiding waste of raw materials and reducing preparation costs; and yielding a mesoporous carbon material with a highly ordered pore structure, a large specific surface area, and good thermal and chemical stability.

The invention discloses a synthetic ammonia catalyst and a preparation method and application thereof, and relates to the technical field of synthetic ammonia. The synthetic ammonia catalyst comprises a carrier and an active component loaded on the carrier, the carrier is nitrogen-doped mesoporous carbon, and the active component is ruthenium-molybdenum bimetallic nitride with a cubic phase crystal structure; wherein the molar ratio of ruthenium to molybdenum in the ruthenium-molybdenum bimetallic nitride is 1: (0.5-2); on the basis of the weight of the nitrogen-doped mesoporous carbon carrier, the loading capacity of the ruthenium-molybdenum bimetallic nitride is 5-15%. According to the method, expensive ruthenium is partially replaced by molybdenum, so that the dosage of the noble metal is reduced by about 40% within the optimized molar ratio range, the cost of per ton of ammonia catalyst is remarkably reduced by 52%, and excessive dependence on the noble metal is effectively relieved. The preparation method is coherent in process and controllable in parameter, and the synthetic ammonia catalyst with excellent low-temperature and low-pressure activity, high cost performance and good dynamic response characteristics can be stably and repeatedly prepared.

A membrane-electrode assembly that simultaneously improves durability and performance is provided. One embodiment of the present invention provides a membrane-electrode assembly that includes a polymer electrolyte membrane, a first catalyst layer disposed on at least one side of the polymer electrolyte membrane, and a second catalyst layer disposed on the polymer electrolyte membrane, the first catalyst layer being interposed between the polymer electrolyte membrane and the second catalyst layer, and the first catalyst layer comprising plate-shaped mesoporous carbon.

The invention belongs to the technical field of electro-catalytic hydrogen evolution, and particularly relates to a metal type cobalt-vanadium carbide heterostructure composite material and a preparation method and application thereof. The method comprises the following steps: dissolving Zn (NO3) 2.6 H2O and Co (NO3) 2.6 H2O in methanol, then adding a 2-methylimidazole methanol solution, uniformly stirring, continuously adding a methanol / water mixed solution containing MXene sol, stirring for reaction, washing, drying to obtain a precursor, and finally putting the precursor in a mixed atmosphere for high-temperature pyrolysis and cooling to obtain the composite electrocatalytic material. According to the method, MOF is adopted for in-situ assembly on the surface of two-dimensional V2C MXene, the composition and structure of a precursor can be effectively controlled, uniform dispersion of a cobalt-vanadium carbide heterostructure in the mesoporous carbon sheet is achieved, and the problems that traditional metal nanoparticles are prone to agglomeration, uneven in distribution and the like are solved. In addition, the synthesis process is simple, convenient and controllable, does not need complex post-treatment or multi-step calcination process, and is suitable for large-scale production.