96results about How to "Lower reaction barrier" patented technology

The invention relates to a cathode material used for a lithium sulfur battery, preparation and an application thereof. The cathode material employs one or more than two carbides or nitrides of metal elements from transition metal as a catalytic component and employs elementary sulfur as an active component. The catalytic component is supported on a carrier firstly and then the active component is supported on the carrier on which the catalytic component is supported. The content of the catalytic component is 2-30% of the total weight of the cathode material and the content of the sulfur is 30-80% of total weight of the cathode material, and the balanced is the carrier. The cathode material, when being used as a cathode in the lithium sulfur battery, has excellent selectivity on reduction of elementary sulfur and reduces reaction energy barrier required for sulfur reduction, reduces reaction polarization and increases discharge voltage platform. The cathode material is environment-friendly, is low in cost and is abundant in resources.

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

The invention discloses a preparation method for an Fe-N-C catalytic material with controllable edge active sites. Under the premise of keeping the original MOF (metal-organic framework) morphology, the preparation method which adopts the method of in-situ embedded molecular aggregate and then high-temperature pyrolysis is intended to change the dosage of small molecules to regulate the frameworkpore structure and the degree of C-N bond rupture, and realizes the control of edge active site number and chemical environment around a single atom for the first time, thus achieving more excellent electrochemical properties. The method adopts an appropriate dosage of small molecules to obtain a ORR (oxygen reduction reaction) catalyst with the specific surface area of 1392.91m<2>/g, the half-wave potential in 0.1M KOH can reach 0.915V(vs.RHE), and the catalytic performance of the Fe-N-C catalytic material is better than the catalytic performance of commercial platinum-carbon catalyst and similar materials. Therefore, the method realizes atom-level active site control and molecule-level structure control, reference significance is provided for the reasonable design of high-performance single-atom catalysts.

The invention discloses a method for synthesizing p type doped silicon carbide by microwave in situ reaction. The steps include: using a group IIIA elementary substance or a compound containing the group IIIA element as the dopant, taking artificial graphite powder, activated carbon, coke or carbon fiber as the carbon source, and employing silicon powder or mixed powder of silicon powder and silicon oxide powder as the silicon source, under a vacuum condition, performing heat preservation for a period of time in a microwave irradiated electromagnetic field so as to obtain the p type doped silicon carbide. The preparation process has no need for raw material pretreatment, a subsequent annealing process or other processes, also has no need for a catalyst, a template and a substrate, etc., and has the characteristics of rapidity, simplicity, high efficiency and good reproducibility. In addition, because of the fast heating speed, uniform heating, small thermal inertia, short production cycle and other advantages unique to microwave irradiation treatment technology itself, the preparation cost is further reduced.

The invention belongs to the technical field of electrode materials, and particularly relates to a copper-based compound/copper nanoelectrode with an interface synergistic effect and a preparation method and application of the copper-based compound/copper nanoelectrode. The electrode comprises a conductive substrate and a copper-based compound/copper nano-catalyst loaded on the surface, the copper-based compound comprises but is not limited to cuprous oxide, copper nitride, copper oxide and other compounds. The invention also discloses a preparation method and application of the electrode. The electrode material with an interface regulation and control function is prepared for the first time, and the reaction energy barrier of carbon monoxide dimerization is reduced by utilizing the synergistic effect of monovalent copper/zero-valent copper, bivalent copper/zero-valent copper and bivalent copper/monovalent copper/zero-valent copper, so that the hydrogen evolution reaction can be well inhibited during electrochemical carbon dioxide reduction, and good selectivity is achieved on multi-carbon products such as ethylene, ethanol and isopropanol.

The invention is applied to the field of metal micro-particle preparation, and provides a reduction method for preparing superfine cobalt powder by hydrazine hydrate. The method comprises the following steps of: preparing mixed solution of cobalt salt and a dispersing agent; preparing cobalt salt complex; and preparing cobalt powder. According to the reduction method provided by the invention for preparing superfine cobalt powder by hydrazine hydrate, firstly, the hydrazine hydrate is added in order to form hydrazine hydrate-cobalt complex, the hydrazine hydrate-cobalt complex is subject to the pH (potential of hydrogen) adjustment and then is added in hydrazine hydrate for reacting, in this way, the reaction potential barrier of hydrazine hydrate and cobalt salt is greatly reduced, the reaction of hydrazine hydrate and cobalt becomes completely and fully, the production efficiency is improved, the production cost is reduced, the prepared cobalt powder is high in purity and is widely used in the industrial field.

The invention provides an iron monatomic catalyst, a preparation method thereof and application thereof in water electrolysis oxygen evolution reaction. The catalyst takes an Fe atom as a metal center and porous carbon P-C as a substrate; and the metal center and the substrate are connected through coordinated oxygen. In the catalyst provided by the invention, iron atoms are uniformly and monodispersedly loaded on the porous carbon P-C, the center of an iron monatom is coordinated with six nearest oxygen atoms, and then is connected with the porous carbon P-C through oxygen to form a Fe-O-C chemical bond, so that charge transfer in the reaction process is facilitated; + 3-valent iron is converted into high-valent iron (Fe < 4 + >) in the reaction process, so that the reaction potential barrier is reduced, and the dynamic process of oxygen evolution is accelerated; and the catalyst shows catalytic activity superior to that of a commercial oxygen evolution catalyst iridium oxide, and has good stability.

The invention belongs to the field of waste electrode material recovery and electrode material preparation, and particularly relates to a nickel-cobalt-manganese multi-metal@ graphitized carbon@ hierarchical pore porous carbon material and a method for preparing the nickel-cobalt-manganese multi-metal@ graphitized carbon@ hierarchical pore porous carbon material through a waste positive electrodematerial. Nanoscale pore channels in the carbon material are communicated with each other; the material is catalyzed and locally graphitized by transition metal; and meanwhile, highly-dispersed nickel, cobalt and manganese are embedded in the material, rich reaction interfaces and lithium ion transmission channels are provided, the polarity of a carbon substrate can be improved through multi-metaldoped porous carbon, conversion of polysulfide is catalyzed through metal particles, and then the specific discharge capacity, the rate and the cycle performance of the lithium-sulfur battery prepared from the positive electrode active material are remarkably improved.

The invention provides a preparation method of a LaCoO3 nanomaterial with surface oxygen vacancies. The method is characterized in that a LaCoO3 nanomaterial is etched in argon plasma to obtain the LaCoO3 nanomaterial with surface oxygen vacancies. The invention also provides an application of the LaCoO3 nanomaterial with surface oxygen vacancies in a reaction for electrochemical reduction of nitrogen to synthesize ammonia. The oxygen vacancies are introduced to improve the performances of the metal oxide LaCoO3 nanomaterial, so the obtained LaCoO3 nanomaterial with oxygen vacancies has the advantages of high catalytic activity, high catalytic stability and high selectivity.

The invention relates to a synthetic method of a cobalt disulfide nanoribbon assembled structure on a titanium substrate; the method comprises: synthesizing cobalt hydroxide nanoribbons on the titanium substrate, preparing cobalt(II,III) oxide nanoribbons on the titanium substrate, preparing cobalt disulfide nanoribbons on the titanium substrate, and performing other steps to obtain the cobalt disulfide nanoribbon assembled structure on the titanium substrate. Compared with the prior art, the method is simple and feasible and good in repeatability, the obtained cobalt disulfide nanoribbons have novel appearance and are distributed evenly on the surface of the titanium substrate, the structure is stable, the structure is in firm contact with the titanium substrate, and electron transport and interfacial reaction are facilitated. The cobalt disulfide nanoribbon assembled structure may be used directly as a two-dimensional material, is widely applicable to the field of electrolytic catalysis and has excellent performance in hydrogen production by water hydrolysis.

The invention relates to a preparation method of mesoporous nitrogen-doped graphene-loaded molybdenum disulfide synthesized by laser irradiation and application of the mesoporous nitrogen-doped graphene-loaded molybdenum disulfide in electrocatalytic hydrogen production. In order to solve the problems that by an existing synthesis process, transition metal oxide/sulfide composite mesoporous nitrogen-doped graphene rich in carbon-pyridine nitrogen metal bonds cannot be synthesized at low temperature and under low pressure, and the content of the carbon-pyridine nitrogen metal bonds in the composite system cannot be regulated and controlled effectively, it is found that the content of the carbon-pyridine nitrogen-molybdenum bonds in the composite catalyst can be improved by irradiating graphene oxide with laser in a range of 177-315 mJ, and in a hydrothermal process, the mass ratio of laser irradiation graphene oxide to tetrathiomolybdic acid as raw materials is 1: 1-1: 8, the loading amount of the molybdenum disulfide on mesoporous graphene can be optimized, thus, while the conductivity of the molybdenum disulfide is improved, the intrinsic activity of the molybdenum disulfide can also be improved synergistically by the carbon-pyridine nitrogen molybdenum bonds at an interface, and the electrocatalysis process of HER is promoted. The preparation method is simple in process, ingenious in design and low in cost, and is safe and environmentally friendly.

The invention discloses an organic compound, which is characterized in that: the compound has the structure of a formula (I): RAn (I); A has a nitrone ligand with the structure of a formula (II); n is 1 or 2; R is selected from one of the following aryl groups: phenyl group or naphthyl group, and R is substituted by one or more of the following groups: hydrogen, nitro group, trifluoromethyl group, halogen, methyl group, methoxy group, hydroxy group, phenyl group, phenolic group and isopropyl group. The compound can be synthesized into a series of catalysts with high catalytic activity and a high turnover rate, various easy-obtained, economic substituted Alpha-phenethyl alcohol compound and phenethyl alcohol compound can be catalyzed under mild conditions to react to prepare various alcohol compounds, the reaction can obtain a high reaction yield in a short reaction time, meanwhile, almost no byproducts are produced, and therefore the reaction is environment-friendly green catalytic reaction and atomic economic catalytic reaction.

The invention discloses a method for preparing trifluoromethylsulfonyl fluoride from trifluoromethylsulfonyl chloride. The method comprises the two steps that (1) the trifluoromethanesulfonyl chlorideis dropped into a solution containing potassium fluoride and 18-crown-6 under nitrogen protection conditions, and during liquid dropping, a reaction system is placed in an ice water bath; (2) after liquid dropping is completed, the reaction continues for 2 hours, and after the reaction is completed, a trifluoromethylsulfonyl fluoride liquid can be collected in a cold trap. The method has the advantages of being short in synthesis route, simple in process flow, high in reaction safety and the like.

The invention belongs to the field of utilization of biomass energy, and concretely relates to a method for preparing 4-vinylphenol through catalytic pyrolysis of gramineous biomass. The method comprises the following steps: loading an alkaline catalyst onto gramineous biomass used as a raw material in an impregnation manner, carrying out catalytic pyrolysis at 230-350 DEG C in an inert atmosphere, and condensing the obtained pyrolysis gas to obtain a liquid product rich in the 4-vinylphenol. The yield of the 4-vinylphenol and the selectivity of the 4-vinylphenol in the organic liquid product are high. The method for preparing the 4-vinylphenol overcomes the defects of low content of the 4-vinylphenol in obtained bio-oil, poor selectivity and high separation and extraction cost of existing gramineous biomass pyrolysis liquefaction technologies, and has a very good application prospect.

The invention provides a method for methane reforming with chemical chain CO2 by applying CO2 to dimethyl ether synthesis. The method comprises the following steps: performing oxidation reduction reaction on Fe3O4 and CH4 in a CH4 oxidation reactor to generate H2, CO and FeO, using H2 and CO as gas sources of dimethyl ether synthesis and transferring FeO into a CO2 reduction reactor; performing oxidation reduction reaction on FeO and CO2 in the CO2 reduction reactor to generate CO and Fe3O4; and using CO as a gas source of dimethyl ether synthesis and returning Fe3O4 to the CH4 oxidation reactor. The invention further provides a device for realizing the method. The device comprises the CH4 oxidation reactor, the CO2 reduction reactor, a first gas-solid separator, a second gas-solid separator, a CO2 absorption device and a dimethyl ether synthesizer. According to the method disclosed by the invention, partial oxidation of CH4 and CO2 reduction in the methane reforming reaction with CO2 are performed in two steps in different reactors through chemical chain combustion with Fe3O4 as the oxygen carrier, so that the reaction energy barrier is reduced, the reaction efficiency is improved, and the method and the device disclosed by the invention have good industrial application prospect.

The invention discloses a rhodium-doped strontium titanate ultrathin nano-layer covered bismuth vanadate photoanode, and a preparation method and application thereof. A BiOI precursor is deposited onthe surface of a fluorine-doped tin oxide (FTO) in a mode of electrochemical deposition; a 0.2M vanadyl acetylacetonate solution is used for exchanging to obtain a bismuth vanadate electrode, and excess V2O5 is removed by using a NaOH solution; and the BiVO4-Rh-SrTiO3 photoanode is synthesized. According to the rhodium-doped strontium titanate ultrathin nano-layer covered bismuth vanadate photoanode provided by the invention, after SrTiO3 subjected to Rh doping is compounded with BiVO4, the photoelectrochemical performance is obviously improved; the electrochemical performance is best when theRh doping amount is 5%; the effect of a heterojunction formed between the BiVO4 and the Rh5%-SrTiO3 is very weak, so that the Rh5%-SrTiO3 exerts a good effect of producing oxygen and assisting catalysis, and the reaction energy barrier of the electrode and an electrolyte contact interface is effectively reduced. In addition, reaction activity sites of the contact interface are increased, so thatholes in a bismuth vanadate valence band can be effectively transferred to the surface of the electrode for an oxidation reaction with water, and the photogenerated electron holes are effectively separated.

The invention provides a catalyst for denitration of low-temperature and low-oxygen tail gas as well as a preparation method and application of the catalyst. The catalyst takes an SBA-15 molecular sieve as a carrier and a ferromanganese oxide as an active component and adsorbs urea at the same time, so that a urea-MnFe/SBA-15 catalyst is obtained; and the invention further discloses a preparation method and application of the low-temperature low-oxygen tail gas denitration catalyst. During application, the catalyst is combined with low-temperature plasma, the quartz wool and the catalyst are uniformly mixed and then fixed in a reactor, and the bed pressure drop is reduced; and the urea is used as a reducing agent to be introduced into the catalyst to directly participate in reaction, and plasma bombardment reaction gas is matched to provide high-energy active species, so that the reaction temperature is reduced, and efficient removal of NO in a low-temperature and low-oxygen environment is realized. The whole denitration process is green and environment-friendly, and the catalyst has no secondary pollution and has a wide application prospect.

The invention provides a magnetic gold-cobalt composite catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. The magnetic gold-cobalt composite catalyst provided by the invention comprises a magnetic cobalt oxide carrier and a gold-cobalt alloy loaded on the surface of the magnetic cobalt oxide carrier, and the chemical composition of the magnetic cobalt oxide carrier is CoOx, wherein x is more than 1 and less than 1.5. In the catalyst provided by the invention, gold and cobalt in the gold-cobalt alloy generate a metal synergistic effect; CoOx has a large number of surface defects and provides a large number of reaction active sites; and the magnetic cobalt oxide carrier and the gold-cobalt alloy active component have strong interaction, so that the catalytic activity of the catalyst for preparing 2,5-dimethylfuran through hydrogenation of 5-hydroxymethylfurfural is improved, the conversion rate of 5-hydroxymethylfurfural is high, and the yield and selectivity of 2,5-dimethylfuran are high.