16results about How to "Guaranteed selectivity" patented technology

The application provides a metal oxide supported active metal catalyst, a preparation method and application thereof. The metal oxide supported active metal catalyst comprises a metal oxide carrier and active metal particles supported on the metal oxide carrier; the loading amount of the active metal is 0.1wt%-5wt% based on 100% of the mass of the metal oxide carrier. It is tested that the hydrogenation reaction of carbonates to prepare formate by using the metal oxide supported active metal catalyst provided by the application as a hydrogen source or using gaseous carbon monoxide with different concentrations and water to provide in-situ hydrogen source for the water gas shift reaction realizes the hydrogenation reaction of carbonates to prepare formate, the yield of the obtained formate is high, the selectivity is above 99%, there is no attenuation after 6 cycles, and the metal oxide supported active metal catalyst has excellent bifunctional effect. In addition, the preparation method of the metal oxide supported active metal catalyst is simple, the operation condition is mild, and the cost is low, so that large-scale production can be realized.

This invention discloses an In-Co-Zr composite catalyst, its preparation method, and its application, relating to the technical field of hydrogenation catalysts. The In-Co-Zr composite catalyst comprises an In₂O₃ support and an active component and structural promoter Zr supported on the In₂O₃ support, wherein the active component includes CoIn. x and Co3InC 0.75 The molar ratio of In, Co, and Zr in the composite catalyst is (1-9):(1.5-2.5):1. The In-Co-Zr composite catalyst exhibits a uniform distribution of active components and a high density of active sites. In the catalytic hydrogenation of CO2 to methanol, it can improve CO2 conversion while ensuring high methanol selectivity, and also possesses good heat resistance and anti-sintering properties. Under reaction conditions of 310℃, the CO2 conversion rate reaches 17.4% and the methanol selectivity reaches 77.7% during the catalytic hydrogenation of CO2 to methanol.

The invention relates to an organic catalyst for 2-heptanone synthesis reaction and a preparation method and application thereof.The organic catalyst is prepared from, by weight, 7-45 parts of active components, 0.1-2.5 parts of auxiliaries and 50-120 parts of carriers, the active components comprise the first active component and the second active component, the weight ratio of the first active component to the second active component is (60: 1)-(3: 1); wherein the first active component is one or more of iron oxide, tungsten oxide, molybdenum oxide, titanium oxide, chromium oxide, vanadium oxide, copper oxide, zinc oxide, nickel oxide, cobalt oxide and manganese oxide; and the second active component is one or more of lanthanum, cerium, indium, praseodymium, neodymium, gadolinium and holmium.

This invention provides a dual-support hydrocracking catalyst, its preparation method, and its application. The dual-support hydrocracking catalyst comprises a composite support and an active metal. The composite support is composed of USY molecular sieve and MCM-41 mesoporous molecular sieve. The active metal comprises at least two transition metal elements. The mass ratio of the composite support to the active metal is (2~5):1; the mass ratio of the USY molecular sieve to the MCM-41 mesoporous molecular sieve is (0.5~2):1. The supported hydrocracking catalyst provided by this invention constructs a microporous-mesoporous synergistic pore structure, balancing activity and stability. By using a dual support composed of USY and MCM-41 in a specific ratio, the strong acidity and high shape selectivity of USY molecular sieve are retained, while the mesoporous structure of MCM-41 solves the problem of limited diffusion of macromolecular raw materials, significantly improving the catalyst's carbon-holding capacity and significantly improving its resistance to colloids and carbon deposition.

The invention discloses a cornus wilsoniana oil catalytic hydrogenation in-situ composite catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier, a bimetallic element generated on the carrier in situ and an in-situ carbon layer uniformly attached to the surface of the bimetallic element, the bimetallic element is composed of an alkali metal element and a non-precious metal element, and the mass percentage of the bimetallic element is 0.5-10 wt% of the total mass of the composite catalyst; the thickness of the in-situ carbon layer ranges from 0.5 nm to 2 nm. The preparation process of the catalyst comprises the following steps: dissolving a bimetallic element raw material in deionized water in a stirring state, slowly adding a dispersing agent for uniform dispersion, adding the carrier in a stirring state, and sequentially drying and performing two-stage calcination after full dipping. The catalyst is used for preparing the aviation kerosene through catalytic hydrogenation of cornus wilsoniana oil, the raw material conversion rate can reach 60%, the target product selectivity is 80% or above, and the technical target that the aviation kerosene can be biochemically treated can be achieved.

The present application belongs to the technical field of natural product chemical modification, and particularly relates to a chemically modified rare ginsenoside derivative, a preparation method and application thereof. The present application takes rare ginsenoside as raw material, introduces a sulfate group by sulfating modification on the rare ginsenoside to obtain a chemically modified rare ginsenoside derivative; the modifier used in the sulfating modification is a sulfonating agent. The rare ginsenoside is synthesized by conversion with ginsenoside Rb1 as raw material and AlCl3 as catalyst in an ethanol system. The modification method of the present application is simple in operation steps, does not require special equipment, is suitable for large-scale production, and has a broad application prospect in the field of drug preparation development and the like.

The application provides a selective hydrogenation method, comprising the following steps: providing a hydrogenation catalyst, which is a carbon-coated nickel nanocomposite with sulfur-containing urea on the surface; contacting a hydrogenation substrate, hydrogen and the catalyst, and catalyzing the reaction under the condition of liquid-phase hydrogenation; the benzene ring of the hydrogenation substrate contains a nitro group and a carbon-carbon unsaturated bond simultaneously. When the benzene ring of the hydrogenation substrate contains a nitro group and a carbon-carbon unsaturated bond simultaneously, the hydrogenation method and the catalyst can hydrogenate the nitro group with high activity and high selectivity.

This invention relates to the field of mineral processing technology, and particularly to a depressant for molybdenum sulfide ore and a flotation separation method and application for copper-molybdenum sulfide minerals. The depressant comprises polyphenols; the polyphenols have the molecular formula C0.05. 32 H 30 O 11 The molecular weight is 590.57 g / mol, and the degree of polymerization is 2-11. The molybdenum sulfide mineral depressant is used for the flotation of copper-molybdenum sulfide minerals. The copper-molybdenum sulfide minerals contain chalcopyrite and molybdenite, with a mass ratio of 1-2:1. This invention provides a molybdenum sulfide mineral depressant and a flotation separation method and application for copper-molybdenum sulfide minerals. The aim is to solve the problems of high toxicity, high loss rate, and high intermingling of existing copper-molybdenum sulfide mineral separation flotation depressants, and to achieve effective separation of chalcopyrite and molybdenite.

The application discloses a method for preventing grade jumping trip of multi-point fault of multi-power distribution network, after detecting the fault, real-time calculation and record of the fault power direction, when the fault occurs in the positive direction of protection, sending the blocking signal to the bus side, when the fault occurs in the reverse direction of protection, sending the blocking signal to the tie side, when the detected fault power direction element only has a single direction, keeping the blocking signal output unchanged, when the positive direction of the fault power element and the reverse direction of the fault power element are detected at the same time, according to the power element direction and the received signal, adjusting the blocking signal output, not receiving the blocking signal, blocking release or receiving the blocking signal but exceeding the total timeout, the protection action outlet. The scheme is simple in configuration and clear in structure, through the fault power direction element judgment and the protection blocking signal, the relay blocking signal and the release blocking signal interaction, the selectivity of the protection action is ensured, the fast positioning and reliable isolation function of the multi-point fault of the multi-power distribution network are realized.

This invention provides a method for preparing a mixed matrix membrane for CO2 separation, including the preparation of an electrospinning precursor solution and electrospinning, the preparation of hollow ZnO nanotubes, the preparation of ZIF-8 hollow nanotubes, the preparation of a modified IL@MOF composite material, the preparation of a casting precursor solution and coating, and the preparation of a mixed matrix membrane for CO2 separation. The mixed matrix membrane for CO2 separation prepared by this invention has high permeability and high adsorption selectivity, and has high promotion and commercialization value.

The application discloses application of a binary aluminum-based layered double metal oxide in degradation of polycyclic aromatic hydrocarbons at low temperature, and degrades polycyclic aromatic hydrocarbons in boiler flue gas in a range of 240-300 DEG C with the binary aluminum-based layered double metal oxide as a catalyst; the content of polycyclic aromatic hydrocarbons in the boiler flue gas is 30000h ‑1 -60000h ‑1 The chemical formula of the binary aluminum-based layered double metal oxide is: wherein M is one of Cu, Mn and Co. The application is aimed at the treatment difficulty of boiler flue gas with only low concentration of PAHs but needing rapid treatment, and a binary aluminum-based layered double metal oxide is designed based on the characteristics of LDOs, which is used for efficient degradation of polycyclic aromatic hydrocarbons at low temperature and has excellent PAHs deep degradation capacity.

This invention discloses a highly stable platinum / palladium-based ammonia oxidation catalyst with a bilayer gradient support, its preparation method, and its applications. The catalyst possesses a multi-level synergistic structure of "atomic-scale dispersed Pd or Pt / V-O-W oxide / hydroxylated TiO₂@(ZrO₂ / Al₂O₃ / CeO₂ or its composite oxide) bilayer gradient support," forming a Pd-O-V / Pt-O-V bonded electronic synergistic system and constructing a protective outer layer with a precise pore size of 2-5 nm. It is constructed through a precise sequential process including hydrothermal hydroxylation modification, atomic layer deposition, sol-gel, and low-temperature reduction post-treatment. The ammonia oxidation catalyst provided by this invention achieves a synergistic effect of intrinsic anti-poisoning and high activity over a wide temperature range. The ZrO₂-CeO₂ composite oxide outer layer further enhances its antioxidant protection capability; the atomic-scale dispersion of Pd or Pt achieves ultra-low loading and high atomic utilization, significantly reducing costs. This invention solves the core technical problems of traditional Pd or Pt-based catalysts being prone to poisoning and deactivation, and having poor low-temperature activity.

The application provides a method for screening mutation sites of enzyme enantioselectivity based on conformation flux. The method quantifies enzyme molecular channel recognition, substrate inlet sampling, active pocket conformation pre-organization, near attack conformation recognition, non-productive pocket stagnation analysis, ligand escape path statistics and gate switching detection, and outputs enantioselectivity mutation site priority and recommended mutation direction.

The application discloses a precoding matrix indication selection method based on a neural network. In the method, a user end first acquires a channel matrix of a downlink; then, the channel matrix is preprocessed by downsampling, segmented discrete Fourier transform and number domain conversion, so that input features suitable for neural network processing are obtained; then, the neural network is used for feature extraction and code word mapping on the preprocessed channel features, corresponding code word numbers are output for each subband, and the code word numbers are converted into precoding matrix indication (PMI) parameters; subsequently, the user end feeds back the PMI to a base station; and the base station maps corresponding precoding matrices according to the same predefined codebook and the received PMI, and the precoding matrices are used for downlink beamforming transmission. The application uses the neural network to replace a conventional traversal search type PMI selection process, reduces the calculation complexity of the user end under the premise of keeping compatibility with an existing codebook feedback mechanism, and improves the PMI selection efficiency.

The invention discloses low-molecular-weight high-activity polyisobutene and a preparation method thereof, and belongs to the field of preparation of high-molecular compounds. According to the preparation method, the low-molecular-weight and high-activity polyisobutene is prepared through catalysis of a simple initiator, a co-initiator and a third component system. And preparing the low-molecular-weight and high-activity polyisobutene with the external olefin proportion of 90% at a relatively high temperature (-30 DEG C to 0 DEG C) by using a simple and easily available initiator and Lewis acid with relatively weak corrosion to equipment as a co-initiator and regulating and controlling a three-component catalytic system and optimizing a process flow. The preparation method comprises the following steps: preparing the low-molecular-weight and high-activity polyisobutene with the external olefin proportion of 90% at a relatively high temperature (-30 DEG C to 0 DEG C).

The invention discloses a self-adaptive three-side differential protection method and device for an auxiliary power system of a hydropower station, and belongs to the technical field of relay protection of power systems. Aiming at the problems that the existing three-side differential protection is easy to mistakenly operate or reject to operate when a switch separation dead zone fault occurs, and the response delay is caused by depending on manual adjustment of a protection mode in a black start process, the method comprises the following steps: constructing a separation dead zone fault detection criterion by monitoring position signals and current states of a three-side switch in real time; when it is judged that the operation condition is the quantile dead zone operation condition, protection logic is automatically switched from three-side differential motion to two-side differential motion, and a maximum unbalanced current threshold is adopted to calculate a ratio braking equation; and a time delay mechanism is introduced to demonstrate issuing of a tripping instruction so as to realize power utilization system protection. According to the method, dead zone faults can be adaptively identified and rapidly isolated, the power supply reliability and the black-start success rate of a hydropower station auxiliary power system are remarkably improved, existing hardware does not need to be transformed, and engineering implementation is easy.