41 results about "Catalyst nanoparticles" patented technology

The invention discloses an iridium oxide catalyst with a dendritic pore structure, a preparation method and application of the iridium oxide catalyst in a proton exchange membrane water electrolysis technology, and belongs to the technical field of water electrolysis. The preparation method comprises the following steps: dissolving an iridium source in water, adding a mixed template agent, dissolving, adding a pore-enlarging agent, and uniformly mixing to obtain a uniform emulsion; and adding an initiator for reaction, after the reaction is finished, centrifugally cleaning for 3-5 times by using a mixed solution of water and absolute ethyl alcohol in a volume ratio of 1: 1, washing off the template agent, and drying to obtain the iridium oxide catalyst with the dendritic pore structure. Compared with commercial iridium oxide catalyst nanoparticles, the iridium oxide catalyst with the dendritic pore structure prepared by the invention provides more active sites, and meanwhile, the mass transmission capability of the catalyst is remarkably improved due to the abundant pore structure, and the diffusion limitation existing in a non-porous material is overcome; therefore, the catalyst shows relatively high activity and stability in PEM electrolyzed water oxygen evolution reaction under low iridium loading, and efficient oxygen evolution catalytic reaction is realized.

The present invention discloses a method for catalytic hydrogenation refining of coking crude benzene, which belongs to the technical field of crude benzene hydrogenation refining, and comprises the following steps: preparing a catalyst carrier; preparing a catalyst impregnation liquid; preparing a catalytic hydrogenation catalyst; catalytic hydrogenation refining; and component separation. The present invention adopts high-temperature co-carbonization technology to combine rectorite with pollen to form a modified carbonized pollen with a multi-level pore structure, which significantly enhances the adsorption, thermal stability and catalytic performance. The hollow structure catalyst nanoparticles prepared by the Kirkendall effect not only increase the active sites, but also promote the internal diffusion of reactants and products, effectively improving the catalytic efficiency. At the same time, the chelation effect of the ionic liquid and the synergistic effect of the oxygen-containing functional group realize the effective loading of the catalyst carrier and the catalyst body, enhance the stability and service life of the catalyst, strengthen its catalytic and desulfurization performance, and provide a new way to achieve efficient and environmentally friendly chemical production.

The utility model belongs to chemical device technical field provides a kind of atomization collision flow type catalyst preparation device, including first raw material tank, second raw material tank, first reaction liquid buffer tank, second reaction liquid buffer tank, reaction tank, first air compressor and second air compressor;The first raw material tank is connected with the reaction tank by the first reaction liquid buffer tank, the second raw material tank is connected with the reaction tank by the second reaction liquid buffer tank, the first air compressor and the second air compressor are all connected to the bottom of the reaction tank;Device is dispersed to raw material by ultrasonic disperser, avoids the problem that reactant gathers and concentration is not uniform.Simultaneously the feeding mode of high-pressure spray makes two air flows to collide quickly, strengthens mixing process, is beneficial to the rapid nucleation of catalyst nanoparticle, reduces reunion phenomenon;Simultaneously reduce the attachment and aggregation of particle in pipeline, reduce the risk of pipeline blockage.

To provide a novel catalyst layer (CL) composition and a structure that provide excellent durability and sustained catalyst performance for contemplated large vehicle applications.SOLUTION: A CL composition and a structure include: an internal composition composed of binder-coated nanoparticles, binder-free catalyst nanoparticles, and regular electrical, ionic, gas, and liquid pathways; a multilayer structure with different packing densities between multiple sub-layers; and an external pattern of an outer surface of the CL. An improvement in CL durability and catalyst performance is achieved, and by using the CL of the present invention, a novel solid electrolytic plating process is demonstrated and a novel thin film coating catalyst product is obtained. The binder-coated nanoparticles function as interconnecting substrates or sites to which nanoparticles that are not coated on their binder-coated surface are adhesively attached, and achieve a regular structure in which the binder-free catalyst nanoparticles are consistently interspersed between the binder-coated nanoparticles and their aggregates.SELECTED DRAWING: Figure 2

The application relates to an iridium oxide catalyst with a dendritic pore structure, a preparation method and application thereof in proton exchange membrane water electrolysis technology, and belongs to the technical field of water electrolysis. An iridium source is dissolved in water, then a mixed template agent is added, a pore expanding agent is added after dissolution, and a uniform emulsion is obtained after mixing uniformly; an initiator is added to carry out reaction, after the reaction is completed, the mixed solution of water and anhydrous ethanol with a volume ratio of 1:1 is used for centrifugal cleaning for 3-5 times, the template agent is washed away, and the iridium oxide catalyst with the dendritic pore structure is obtained after drying. Compared with commercial iridium oxide catalyst nanoparticles, the prepared iridium oxide catalyst with the dendritic pore structure provides more active sites, meanwhile, the rich pore structure significantly improves the mass transfer capacity of the catalyst, diffusion limitation existing in the poreless material is overcome, therefore, in a low iridium load, the PEM water electrolysis oxygen evolution reaction exhibits higher activity and stability, and high-efficiency oxygen evolution catalytic reaction is realized.

The invention relates to a preparation method of a ruthenium-based acidic water electrolysis hydrogen production catalyst, and belongs to the technical field of clean renewable energy nanometer materials and catalysis. The method is characterized in that a carbon carrier and a metal compound are adopted as precursors, a polyol reduction method is adopted, carbon-loaded ruthenium-based alloy nanoparticles are obtained, and then the ruthenium-based catalyst is prepared through low-temperature pyrolysis under the air condition. The ruthenium-based catalyst nanoparticles are uniform in size, compared with a conventionally adopted hydrothermal method, the method is simple in step, controllable in morphology and uniform in size distribution, and meanwhile, the prepared material has high catalytic activity and stability and can be applied to cathode and anode catalyst materials of a proton exchange membrane water electrolysis device.

The present invention discloses an apparatus and a method for preparing single-walled carbon nanotubes by a two-step process. The apparatus includes a carbon nanotube growth chamber, a product collection module, a catalyst supply module, a carbon source supply module, and an etchant supply module; the carbon source supply module is used to introduce a first gas stream containing a carbon source in a first direction, and the etchant supply module is used to introduce a second gas stream containing an etchant in a second direction, and the first direction and the second direction are opposite to each other so that the gas streams intersect to form a vortex; the catalyst supply module introduces catalyst particles in a third direction, and the third direction points to the vicinity of the position where the vortex is located; the product collection module is arranged above the vortex to collect the formed single-walled carbon tubes. The present invention realizes the controllable preparation of catalyst nanoparticles and the orderly separation of the carbon nanotube growth step, reduces the influence of confounding variables on the reaction, the counter-directional intersection of the gas streams forms a vortex, and the vortex avoids the problem of local deposition and blockage of the tangential laminar flow, thereby avoiding the influence on the quality and continuous growth of carbon nanotubes.

A high temperature fuel cell includes an anode, a cathode, a polymer electrolyte membrane disposed between the anode and the cathode, phosphoric acid, and a cathode catalyst disposed on the cathode and in contact with the phosphoric acid. The cathode catalyst includes a Pd-containing core or a Pt-containing core, a Pt-containing shell, in a compressed state, on the Pd-containing core, and an anti-phosphate poisoning surface modifier disposed on the Pt-containing shell.

Carbon nanofiber doped alumina (Al—CNF) supported MoCo catalysts in hydrodesulfurization (HDS), and / or boron doping, e.g., up to 5 wt % of total catalyst weight, can improve catalytic efficiency. Al—CNF-supported MoCo catalysts, (Al—CNF—MoCo), can reduce the sulfur concentration in fuel, esp. liquid fuel, to below the required limit in a 6 h reaction time. Thus, Al—CNF—MoCo has a higher catalytic activity than Al—MoCo, which may be explained by higher mesoporous surface area and better dispersion of MoCo metals on the AlCNF support relative to alumina support. The BET surface area of Al—MoCo may be 75% less than Al—CNF—MoCo, e.g., 166 vs. 200 m2 / g. SEM images indicate that the catalyst nanoparticles can be evenly distributed on the surface of the CNF. The surface area of the AlMoCoB 5% may be 206 m2 / g, which is higher than AlMoCoB 0% and AlMoCoB 2%, and AlMoCoB 5% has the highest HDS activity, removing more than 98% sulfur and below allowed levels.

The invention relates to the field of diameter and conductive property controlled growth of single-walled carbon nanotubes, in particular to a method for growing a sub-nano diameter semiconductor single-walled carbon nanotube in a crystal face step height confinement. According to the method, a crystal face (110) of a zirconium oxide single crystal substrate is screened, the atomic step height of the crystal face (110) of the zirconium oxide single crystal substrate is regulated and controlled through heat treatment, and the small-diameter catalyst nanoparticles are prepared through steps with the small crystal face height. By adopting a normal pressure chemical vapor deposition method, the controllable growth of the diameter and the conductive property of the single-walled carbon nanotube is realized by utilizing a confinement space provided by the step. By selecting the crystal face of the substrate and regulating and controlling the step height, based on the strong interaction between the single-walled carbon nanotube and the atomic step of the substrate, the controlled preparation of the semiconductor single-walled carbon nanotube with sub-nanometer diameter and narrow chiral distribution is realized, and a new candidate single crystal substrate is provided for the controlled growth of the single-walled carbon nanotube; and a material foundation is laid for the development of carbon nanotube-based nano-electronic devices.

The invention provides a modified catalyst and a preparation method thereof, a membrane electrode, a fuel cell and application, the modified catalyst comprises a catalyst matrix and a modified layer loaded on the outer surface of the catalyst matrix, the catalyst matrix is a Pt / C catalyst, and the structural formula of the material of the modified layer is SiO2-(CH2) 3SH. By adopting the modified catalyst provided by the invention, on one hand, when the modified catalyst is applied to a membrane electrode, the coverage of an ionomer on catalyst nanoparticles can be reduced, so that active sites of the catalyst are increased, and the catalytic performance is improved; and on the other hand, the local oxygen mass transfer resistance in the cathode catalyst layer can be greatly reduced, so that the cathode catalyst layer has better catalytic activity and mass transfer rate, and the comprehensive performance is better.

The invention provides a bio-based degradable foaming material and a preparation method thereof, and relates to the technical field of biodegradable materials. The invention aims to solve the problems that the existing PBAT / TPS foaming material is thick and large in foam hole, deteriorated in mechanical property, unstable in foaming process and the like due to poor interfacial compatibility and insufficient melt strength. According to the method, PBAT and TPS are used as matrixes, maleic anhydride grafted PBAT is added as a reactive compatibilizer, nanoparticles are added as a physical reinforcing and nucleating agent, and a chemical foaming agent AC and a catalyst ZnO are matched. The foaming material is prepared through a high-speed mixing and hot-pressing foaming one-step forming process. The composite material comprises the following raw materials in percentage by weight: 10-40% of TPS, 60-90% of PBAT, 1-5% of a foaming agent, 1-5% of a compatilizer, 0-3% of a catalyst and 0.5-5% of a nanoparticle nucleating agent. The prepared foaming material has high foaming ratio and good compression strength and rebound resilience, can be completely biodegraded, and is suitable for the fields of logistics packaging, electronic product protection and the like.

The present invention provides a hydrogen energy electrode and a preparation process thereof, wherein the preparation process includes: cleaning and pre-treating the selected base material according to the electrode processing requirements to remove impurities and pollutants on the surface of the base material; selecting the catalyst material according to the electrode processing requirements and preparing catalyst nanoparticles by chemical reduction or electrochemical deposition; uniformly coating the prepared catalyst nanoparticles on the base material to form a catalyst layer on the surface of the base material to obtain an electrode pre-processed body; covering the electrode pre-processed body with a proton exchange membrane coated with the catalyst layer to form an electrode pre-finished product; and post-treating the electrode pre-finished product to obtain a hydrogen energy electrode. The overall preparation process of the present invention is simple, easy to operate, and low in cost. The performance of the prepared electrode is more stable, and the bonding force between the proton exchange membrane and the catalyst layer is strong, which effectively improves the efficiency and service life of the battery.

The invention discloses a low-cost silicon nanowire material and a preparation method thereof, and belongs to the technical field of secondary resource utilization. The preparation method comprises the following steps: pre-treating a waste photovoltaic silicon plate to obtain a high-purity silicon wafer; putting the high-purity silicon wafer into a first deposition solution, and depositing Ag catalyst nanoparticles on the surface of the high-purity silicon wafer; washing the high-purity silicon wafer with the Ag catalyst nanoparticles deposited on the surface; putting the high-purity silicon wafer into a second deposition solution, and depositing a Cu layer on the Ag catalyst nanoparticles; and putting the high-purity silicon wafer into the etching solution to etch the high-purity silicon wafer to obtain the silicon nanowire material. According to the invention, the etching rate can be improved, the silicon nanowire material obtained by etching is ensured to have good morphology uniformity and quality, and the preparation cost is effectively reduced.

Improved photocatalysis is provided for chemical reactions involving hydrogen in two component plasmon-catalyst nanoparticles. The main idea of this work is to configure the optical illumination of the nano-articles to suppress formation of an undesirable hydride phase in the nanoparticles. This idea is broadly applicable to any chemical reaction involving hydrogen. Specific examples considered experimentally in this work are acetylene hydrogenation to produce ethylene, carbon dioxide reduction and ammonia synthesis.

Carbon nanofiber doped alumina (Al—CNF) supported MoCo catalysts in hydrodesulfurization (HDS), and / or boron doping, e.g., up to 5 wt % of total catalyst weight, can improve catalytic efficiency. Al—CNF-supported MoCo catalysts, (Al—CNF—MoCo), can reduce the sulfur concentration in fuel, esp. liquid fuel, to below the required limit in a 6 h reaction time. Thus, Al—CNF—MoCo has a higher catalytic activity than Al—MoCo, which may be explained by higher mesoporous surface area and better dispersion of MoCo metals on the AlCNF support relative to alumina support. The BET surface area of Al—MoCo may be 75% less than Al—CNF—MoCo, e.g., 166 vs. 200 m2 / g. SEM images indicate that the catalyst nanoparticles can be evenly distributed on the surface of the CNF. The surface area of the AlMoCoB5% may be 206 m2 / g, which is higher than AlMoCoB0% and AlMoCoB2%, and AlMoCoB5% has the highest HDS activity, removing more than 98% sulfur and below allowed levels.

Provided herein are methods that involve the use of nanobubbles for fabrication of porous thin films that can be used to form articles such as electrodes, membranes, and photovoltaic cells. One such method includes combining nanobubbles with catalyst nanoparticles, a liquid carrier, and an ionomer to form a coating composition; applying the coating composition to a substrate to form a coated substrate; and removing the liquid carrier from the coated substrate to form an electrode including a porous thin film on the substrate.

A method for producing an ion conducting membrane comprising a membrane layer comprising a reconstitution catalyst. The film layer is made from an ink comprising a stabilized dispersion of reconstitution catalyst nanoparticles. Also provided are ion conducting membranes for electrochemical devices, such as fuel cells or water electrolysers, having a membrane layer comprising a reconstitution catalyst, the membrane layer comprising dispersed reconstitution catalyst nanoparticles, a nanoparticle stabilizer, and an ion conducting polymer.

Carbon nanofiber doped alumina (Al-CNF) supported MoCo catalysts in hydrodesulfurization (HDS), and / or boron doping, e.g., up to 5 wt % of total catalyst weight, can improve catalytic efficiency. Al-CNF-supported MoCo catalysts, (Al-CNF-MoCo), can reduce the sulfur concentration in fuel, esp. liquid fuel, to below the required limit in a 6 h reaction time. Thus, Al-CNF-MoCo has a higher catalytic activity than Al—MoCo, which may be explained by higher mesoporous surface area and better dispersion of MoCo metals on the AlCNF support relative to alumina support. The BET surface area of Al—MoCo may be 75% less than Al-CNF-MoCo, e.g., 166 vs. 200 m2 / g. SEM images indicate that the catalyst nanoparticles can be evenly distributed on the surface of the CNF. The surface area of the AlMoCoB5% may be 206 m2 / g, which is higher than AlMoCoB0% and AlMoCoB2%, and AlMoCoB5% has the highest HDS activity, removing more than 98% sulfur and below allowed levels.

The application discloses a bimetallic MOFs mediated morphology controllable catalyst, a preparation method and application thereof, and the preparation method comprises the following steps: respectively adding iron salt, cobalt salt and an organic ligand into an organic solvent, then adding an alkaline adjusting agent and a surfactant; transferring the stirred solution into a reaction kettle to perform a solvothermal reaction, centrifuging the suspension after the reaction, washing and drying the suspension for multiple times to obtain a bimetallic organic framework (MOFs) precursor; and obtaining the catalyst after heat treatment of the bimetallic organic framework (MOFs) precursor in a gas atmosphere. The one-step solvothermal method is used to obtain the bimetallic MOFs, the size and morphology of the product are controlled through the alkaline adjusting agent, and the agglomeration of the catalyst nanoparticles can be reduced by adding the surfactant. The preparation method is simple, the specific surface area of the product is high, when the catalyst is used for preparing high-carbon hydrocarbons through catalytic hydrogenation of carbon dioxide, the carbon dioxide conversion rate is as high as 47.82%, the selectivity of the high-carbon hydrocarbons reaches 59.68%, the selectivity of the by-products carbon monoxide and methane is low, and the catalytic activity is good.

Provided herein are methods that involve the use of nanobubbles for fabrication of porous thin films that can be used to form articles such as electrodes, membranes, and photovoltaic cells. One such method includes combining nanobubbles with catalyst nanoparticles, a liquid carrier, and an ionomer to form a coating composition; applying the coating composition to a substrate to form a coated substrate; and removing the liquid carrier from the coated substrate to form an electrode including a porous thin film on the substrate.

The utility model relates to a plasma technology-based single-walled carbon nanotube preparation device, which comprises a plasma generator, a preparation box and a cooling box, the plasma generator comprises a cavity, a solid catalyst electrode, a rotary telescopic motor, a stun gun and an arc striking gas injection pipe, and an inclined plate is arranged in the preparation box. According to the utility model, the rotary telescopic motor is started to drive the solid catalyst electrode to do regular front-back rotary motion, the catalytic promoter is introduced through the arc striking gas injection pipe, and the stun gun is started to carry out arc discharge, so that the catalytic promoter and the solid catalyst electrode are combined in situ to generate catalyst nanoparticles; the plasma arc bombards different surfaces of the solid catalyst electrode every time, the evaporation rate of the solid catalyst electrode is reduced, catalyst nanoparticles with the uniform size are obtained, a carbon source material is placed on an inclined plate, when the carbon source material falls to the height of the solid catalyst electrode, the carbon source material and the catalyst nanoparticles are subjected to catalytic cracking, and single-walled carbon nanotubes with the uniform size are generated; the product quality and the production efficiency are improved.

The invention discloses a PEM electrolytic bath in-situ activation method, and relates to the field of electrolytic bath activation, and the PEM electrolytic bath in-situ activation method comprises the following steps: preparing an acidic solution with the H < + > concentration of 0.1-0.5 M; an acid solution is injected into the cathode flow channel for acid introduction treatment; electrifying in an acid introducing period; washing the cathode flow channel with deionized water until the pH value of effluent is neutral, and blowing and drying the cathode flow channel; carrying out an air tightness test; electrifying to test performance indexes of the electrolytic cell; according to the PEM electrolytic cell in-situ activation method, an acid solution is introduced into a cathode runner of an electrolytic cell for reaction and electrification to promote electrochemical activation, the acid solution dissolves oxides on the surface of a catalyst, active sites are exposed, impurities on the surface of a proton exchange membrane are removed, and a reaction interface is improved; in addition, the acid environment can promote redispersion of the agglomerated catalyst nanoparticles and increase the surface area, after acid solution treatment, the poisoning phenomenon of the membrane electrode is eliminated, impurities in the proton exchange membrane are removed, the proton exchange membrane is recovered to the initial physical state, and various performance indexes are recovered.

The invention belongs to the technical field of electrochemistry, and particularly relates to a metal catalyst with the surface grafted with anion groups and a preparation method and application of the metal catalyst. The catalyst is formed by grafting small organic molecules with anion groups on the basis of an existing metal catalyst. Hydroxyl adsorbed on the surface of a metal catalyst is used as an active site and is covalently bound with organic molecules through chemical bonds, and anion groups are anchored on the surface in a strong bonding manner, so that the bonding strength of the anion groups and the catalyst is enhanced, and the anion groups are prevented from falling off and losing; besides, after the anionic groups are grafted, the potential of the surfaces of the catalyst nanoparticles is increased compared with that before, sedimentation and agglomeration of the catalyst nanoparticles in the process of preparing catalyst slurry are slowed down, and preparation and production of industrial-grade catalyst slurry and membrane electrodes are facilitated. The invention provides a feasible way for reasonable design and successful preparation of the anion modified catalyst, and has a wide application prospect.

A catalyst slurry for fuel cells, its preparation, and its application belong to the field of proton exchange membrane fuel cell technology. The catalyst slurry comprises: molecular carbon electronic materials, a platinum-based catalyst, a perfluorosulfonic acid ionomer, water, and an alcohol solvent. The molecular carbon electronic material forms a permeable interfacial layer on the surface of the platinum-based catalyst nanoparticles. On the one hand, it acts as an electron buffer to regulate the electronic structure of platinum active sites to optimize the adsorption of oxygen reduction intermediates; on the other hand, it acts as a geometric shielding layer to weaken the adsorption poisoning of the platinum surface by the ionomer sulfonic acid groups and reduce interfacial oxygen transport resistance. Thus, it simultaneously improves the activity, durability, and mass transfer performance of the membrane electrode assembly without hindering gas diffusion. The molecular carbon-co-platinum-based catalyst of this invention can be used to prepare cathode catalyst layers, membrane electrode assemblies, and fuel cell stacks, showing promising application prospects of reducing the amount of precious metals used and achieving high power density and long-life operation.

The invention belongs to the technical field of carbon nanotubes, and relates to a single-walled carbon nanotube and a single-walled carbon nanotube continuous preparation method based on methane and a floating catalyst, and the method comprises the following steps: continuously injecting a metal catalyst precursor and an optional auxiliary agent into an evaporation chamber in a spraying manner, a first path of carrier gas is introduced into the obtained mixed gas flow to accelerate gas flow, the first path of carrier gas is inert gas, and a raw material flow is obtained; the raw material flow, a second path of carrier gas and a silicon source precursor are continuously injected into the high-temperature tubular reactor for a high-temperature vapor deposition reaction, and the second path of carrier gas contains methane, hydrogen and inert gas; the metal catalyst precursor is decomposed to form active catalyst nanoparticles, and methane is subjected to catalytic cracking and deposition, so that the single-walled carbon nanotubes continuously grow. By adopting the method, the yield and the purity of the single-walled carbon nanotube can be improved, and the diameter distribution of the obtained single-walled carbon nanotube is uniform.

The invention discloses a flow battery electrolyte and application thereof, the flow battery electrolyte comprises a catalyst dispersion liquid, the catalyst dispersion liquid comprises MnO2 nanoparticles, TiO2 nanoparticles and an organic solvent, and the organic solvent comprises polyvinylpyrrolidone; the mass ratio of the MnO2 nanoparticles to the TiO2 nanoparticles is (3: 1)-(0.3: 1); the mass ratio of the polyvinylpyrrolidone to the catalyst nanoparticles is (1-3): 1. The nano-scale catalyst which is cross-system, easy to disperse, capable of being directly added into electrolyte and low in cost is developed and prepared into the dispersing agent to be applied to the electrolyte, the problems that the catalyst agglomerates and falls off, the utilization rate of active sites is low, stability is poor and the like are solved, and the preparation method is short in preparation period, low in cost and suitable for large-scale production. The coulombic efficiency, the voltage efficiency, the energy efficiency and the cycle capacity retention ratio of the flow battery prepared from the flow battery electrolyte are improved.

The invention discloses a method and a device for preparing a single-walled carbon nanotube, and belongs to the technical field of semiconductor materials. The method comprises: providing an anode comprising a carbon source, a first metal element, and a second metal element; applying arc discharge to form core-shell structure catalyst nanoparticles having a core rich in a second metal element and a first metal carbide shell layer in situ, and catalytically growing single-walled carbon nanotubes; and at the same time of stopping the arc discharge or within an extremely short time after the arc discharge, performing a quenching step on the reaction region at an ultrahigh cooling rate of more than or equal to 105K / s, and suddenly reducing the temperature of the reaction region from no less than 1000 DEG C to no more than 400 DEG C. According to the method disclosed by the invention, the problems of overlarge pipe diameter and wide distribution caused by high-temperature agglomeration of the catalyst and uncontrollable growth process in the prior art are solved through cooperative regulation and control of catalyst source size clamping and dynamic freezing in the growth process, and controllable preparation of the high-quality single-walled carbon nanotube with the average pipe diameter smaller than 1.2 nm and extremely narrow distribution is realized.

The present invention belongs to the technical field of nanomaterial preparation, and relates to an apparatus and method for preparing oligo-walled carbon nanotubes by scalable arc discharge. The apparatus comprises: at least one synthesis unit, at least one scraping unit, at least one barrier unit, at least one collection unit, a catalyst melt, and a drive unit. The present invention uses a rotating catalyst melt connected to a dual-electrode DC arc to continuously prepare uniform catalyst nanoparticles. The rotating melt and the scraping unit cooperate to remove coke attached to the surface of the catalyst melt, keeping the catalyst surface clean, which is conducive to the sustainable preparation of uniform catalyst nanoparticles for the growth of oligo-walled carbon nanotubes and maintaining the equipment's long-term stable growth of oligo-walled carbon nanotubes. This is particularly important for achieving both high-yield and high-quality oligo-walled carbon nanotubes, and has significant commercial value.

The invention discloses a method for preparing a nitrogen supercritical dispersion catalyst. The method comprises the following steps: S1, preparing a catalyst solution; s2, high-purity nitrogen is introduced into the reaction kettle, replacement is conducted 2-5 times, and the oxygen content < lt > is ensured; 5 ppm; s3, heating the reaction kettle to 200-250 DEG C, pressurizing to 10-15 MPa, and continuously introducing supercritical nitrogen to form a supercritical nitrogen environment; s4, the catalyst solution is injected into a net type nozzle through a high-pressure plunger pump for primary atomization, and micron-sized primary liquid drops are produced; and S5, spraying the primary liquid drops into the supercritical nitrogen environment of the reaction kettle for secondary atomization, carrying out explosive refining on the primary liquid drops by virtue of ultrasonic cooperation and an ultrasonic cavitation effect, and instantaneously extracting a solvent in the catalyst solution by virtue of supercritical nitrogen, so as to generate solid catalyst nanoparticles. According to the method for supercritical dispersion of the catalyst through nitrogen, agglomeration inhibition in the supercritical nitrogen environment and two-stage atomization are adopted to achieve nanocrystallization of the catalyst, the traditional catalyst dispersion bottleneck is broken through, and a solid foundation is provided for controllable preparation of high-performance SWCNT.