2753 results about "Side reaction" patented technology

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 3, 4 '-diaminodiphenyl ether.The preparation method comprises the steps that m-dinitrobenzene is dissolved with alcohol, and selective hydrogenation is conducted in a high-temperature and high-pressure reaction kettle with a palladium catalyst; and co-heating and refluxing the product after selective hydrogenation, a strong alkali aqueous solution, a first solvent and a phase transfer catalyst to obtain the m-aminophenol salt. M-aminophenol salt, p-nitroiodobenzene, alkali and a second solvent are subjected to a co-heating reaction, and then 3-amino-4 '-nitrodiphenyl ether is obtained through post-treatment; the method comprises the following steps: dissolving 3-amino-4 '-nitrodiphenyl ether with alcohol, carrying out hydrogenation reduction with a palladium catalyst, and carrying out post-treatment purification to obtain 3, 4'-diaminodiphenyl ether. According to the method, common m-dinitrobenzene is used as a raw material, m-nitroaniline is obtained through selective hydrogenation, m-aminophenol salt is prepared through the m-nitroaniline, then etherification reaction is carried out, the reaction yield is higher, the purity is better, and side reactions are few.

The invention relates to a multi-section quench trickle bed reaction system and reaction method for liquid phase hydrogenation of aldehyde and ketone, the system comprises a multi-section quench liquid phase hydrogenation reactor filled with at least two sections of catalyst bed layers, a product circulating liquid inlet is arranged above each section of catalyst bed layer and is used for introducing a product circulating liquid into the corresponding catalyst bed layer; the adiabatic temperature rise of each section of the catalyst bed layer of the reactor is independently controlled by controlling the flow and the temperature of the circulating quenching liquid of each section of the catalyst bed layer; the method can effectively reduce the adiabatic temperature rise of the catalyst bed layer, prolong the service life of the catalyst, reduce the occurrence of side reactions, improve the product quality and yield, reduce the circulation volume of the liquid-phase product, and reduce the energy consumption. And a better hydrogenation effect can be realized by adopting a single trickle bed reactor, so that the equipment investment is reduced.

The invention discloses a modified carbon-coated sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, and relates to the technical field of new energy materials. The preparation method comprises the following steps: preparing MnFe-MOF from a manganese source, a first iron source and a first organic ligand under a hydrothermal reaction; a second iron source, the MnFe-MOF and a second organic ligand are subjected to a hydrothermal reaction, and MnFe-MOF / Fe-MOF is obtained; uniformly mixing with a sodium source and a phosphorus source, and sintering to obtain a positive electrode material; and carrying out high-temperature gas-phase etching treatment to obtain the fluorine-doped carbon-coated modified sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material. The material disclosed by the invention has a coating modified structure, so that an interface side reaction caused by direct contact between sodium ferromanganese phosphate and an electrolyte can be effectively avoided, a manganese dissolution phenomenon is reduced, and the structural stability of the material is improved; and meanwhile, the material has high conductivity, excellent structural stability, excellent long cycle life and excellent rate capability.

The invention relates to a method for purifying a monomer bis (2-hydroxyethyl) terephthalate (BHET) obtained by depolymerizing waste polyester through ethylene glycol (EG), and belongs to the technical field of polyester recycling. The BHET microwave radiation induced film evaporation separation and molecular distillation refining continuous process provided by the invention solves the problems of long process flow, poor continuity, more side reactions and low purity and yield in the direct separation and refining process of BHET in alcoholysis liquid based on a gas-liquid equilibrium separation method at present. The whole technological parameter requirement is mild, the process is short, continuity is good, the BHET purity of the product is larger than or equal to 99.0 wt%, the hue is good, and the BHET yield is larger than or equal to 80.0%. And meanwhile, the method has the advantages that EG is conveniently recycled in a system, the production process is cleaner and more environment-friendly, and the comprehensive efficiency advantage is obvious.

The invention provides a continuous purification method of crude acetonitrile, and belongs to the field of acetonitrile purification. The continuous purification method of the crude acetonitrile comprises the following steps: rectification light component removal, membrane separation impurity removal, adsorption impurity removal and rectification purification. According to the continuous purification method of the crude acetonitrile, continuous purification of the crude acetonitrile can be realized, and meanwhile, the problems that new impurities are introduced by side reactions, the rectification efficiency and the rectification stability are influenced by treated products and the device is influenced by over-high alkalinity of the treated secondary rectification liquid due to the fact that sodium hydroxide and formaldehyde are adopted to treat the rectification liquid are avoided; the acetonitrile product with the purity meeting the requirement is prepared by continuously purifying the crude acetonitrile.

The invention discloses a preparation method of a pyrazolone amino-acid ester derivative. The pyrazolone amino-acid ester derivative is obtained through three-component cascade reaction by taking pyrazolone imine, a pentafluorophenylacetate derivative and alcohol as reactants and chiral isothiourea as a catalyst. According to the invention, challenges of competitive side reactions between a plurality of reaction substrates and intermediates and stereoselectivity control are overcome, the application range of the substrate combination of the existing system is broken through, and synthesis of a series of pyrazolone amino-acid ester derivatives is realized in a green and efficient manner. According to the method disclosed by the invention, substrate preassembly is not needed, transition metal catalysis is not needed, raw materials and the catalyst are cheap and easy to obtain, reaction conditions are mild, and the substrate application range is wide. In addition, the invention also provides a new way for introducing the medicine bioactive molecules into the synthesis of the pyrazolone amino-acid ester compound.

A method for visible light-mediated chemical modification of a polypeptide or protein based on cysteine includes the following steps: allowing a cysteine residue on a cysteine-containing oligopeptide, polypeptide, or protein to undergo a reaction with an activating reagent to generate a free radical precursor in situ; and subjecting the free radical precursor to desulfurization under photocatalytic condition, and allowing the generated free radical intermediate to undergo an addition reaction with an olefin or an alkyne, such that sulfhydryl removal and carbon-carbon bond construction are achieved to produce a chemical modification product of the polypeptide and protein. The method cleverly avoids the influence on the chiral center, and thus the chirality of the amino acid residue can be retained. The method is conducive to well avoiding the occurrence of side reactions, and thus the efficiency of the entire conversion is very high.

The invention discloses an ethylene-vinyl alcohol copolymer and a preparation process thereof, and relates to the technical field of EVOH. According to the preparation process of the ethylene-vinyl alcohol copolymer, through gradient control of EVA polymerization and alcoholysis process conditions, on one hand, uniform control of heat release in a polymerization stage and an alcoholysis stage can be realized, heat in each stage is fully utilized, and the conversion rate and alcoholysis efficiency in the polymerization process are improved; on the other hand, effective regulation and control of EVOH composition, molecular weight distribution, molecular chain sequence structure and stereoregularity can be realized; finally, side reactions in the polymerization stage and the alcoholysis stage can be reduced, and generation of gel and impurities is reduced.

The invention discloses a solid electrolyte with high ionic conductivity, which comprises the following components: a matrix material: a halide super ion conductor with a LiMXCl4 structure, M being selected from at least one of Ta, Nb and Hf, X being O or F, a chemical general formula being LiM1-aX1-6Cl4, a being equal to 0.1-0.3, and an electrochemical window being regulated to 2.5-4.0 V through fluorine-chlorine mixed anion substitution; the second phase material is a core-shell structure compound, the core is Li3TiCl6, and the shell is a Li3PS4 interface layer; and the sintering aid is a compound of Li3BO3 and LiF. Through fluorine-chlorine mixed anion regulation and control and MO2Cl4 octahedron synergistic tilting mechanism, the ionic conductivity of the solid electrolyte is remarkably improved, the lithium ion conductivity at room temperature is greater than or equal to 10mS / cm, the activation energy is less than or equal to 0.2 eV and is superior to that of the traditional halide electrolyte, and meanwhile, the free volume between chains is optimized through Zr < 4 + > / Sn < 2 + > gradient doping, so that the performance of the solid electrolyte is improved. The core-shell structure compound and the silane coupling agent are combined for modification, so that the electrochemical window is effectively widened to 2.5-4.0 V, the interface side reaction is inhibited, and the composite material is adaptive to a high-voltage positive electrode material.

The invention discloses a device for continuously preparing adiponitrile from adipic acid by supergravity, which is characterized in that a specially designed gas-in-liquid mixed feeding mode is firstly adopted, so that liquid of a falling film assembly is uniformly dispersed as far as possible, and meanwhile, by accurately controlling the reaction temperature in the falling film assembly, side reactions are reduced; secondly, the contact mode of gas and liquid of the falling film assembly is changed, the gas-liquid countercurrent contact mode is changed into gas-liquid parallel flow, and the liquid is prevented from being stopped in a pipeline through the gas-liquid parallel flow; and finally, mixing and mass and heat transfer effects of adipic acid and ammonia molecules in the reaction process are enhanced by using a supergravity assembly, so that adipic acid decomposition and coking in a bubbling section of a traditional reactor are effectively slowed down, the reaction efficiency and the product yield are improved, and side reactions are reduced.

The invention provides a closed-loop reaction continuous production process for producing pigment violet 23, which comprises the following steps: a) adding an NMP (N-Methyl Pyrrolidone) solvent into a 100L reaction kettle, starting and stirring to 30 DEG C, adding a reduzate, and stirring for 30 minutes; b) adding sodium carbonate after the step a), and continuously stirring for 30 minutes; c) slowly adding chloranil, keeping the temperature at 35-40 DEG C, and continuously reacting until the reaction is finished; d) transferring the material in the step c) to closed-loop reaction equipment, and controlling the feeding sequence, mode and complete reaction of each component by utilizing a multi-component reaction optimization technology to ensure the reaction of reactants and reduce the generation e of side reaction to the maximum extent; the adding sequence, the reaction environment, the pressure and the flow speed of reactants are accurately controlled in the reaction process, and the high yield and the high purity of the pigment purple 23 are guaranteed; f) continuously carrying out catalytic oxidation reaction in the closed loop by using a static mixer and a small amount of catalyst combination to obtain a product; by optimizing the continuous production process of the closed-loop reaction of the pigment violet 23, adopting a closed-loop reaction system, and performing continuous production and flow marking monitoring and control, the method disclosed by the invention achieves obvious good effects in a plurality of aspects; the production efficiency is improved, the product quality is guaranteed, the production cost is reduced, the environmental friendliness is improved, and the process stability is enhanced.

The present application provides a device and method for preparing methyl isoamyl ketone. In the method, acetone and isobutyraldehyde are reacted under the catalysis of a condensation catalyst and a hydrogenation catalyst in the presence of hydrogen to obtain the methyl isoamyl ketone, wherein the condensation catalyst comprises an organic base; and the molar ratio of the condensation catalyst to the isobutyraldehyde is (0.02-0.15):1. The MIAK obtained by the method has at least one of the advantages of high conversion rate, simple process flow, low production cost, easy separation of side reaction products, and high product purity.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

To provide a method for manufacturing a thin film, capable of greatly improving step coverability and thin film thickness uniformity even when forming a thin film on a substrate having a complicated structure by controlling a side reaction to reduce a thin film growth rate and removing a process by-product in the thin film.SOLUTION: A method for manufacturing a thin film comprises the steps of: i) adsorbing a growth inhibitor for thin film formation represented by chemical formula (1) on a substrate surface; and ii) adsorbing a Ti-based thin film precursor on the substrate surface having the adsorbed growth inhibitor. AnBmXo (1) (where, A is carbon or silicon; B is hydrogen or 1-3C alkyl; X is halogen; n is any integer of 1-15; o is an integer of one or more; and m is 0 to 2n+1.).SELECTED DRAWING: Figure 2

The invention discloses a reaction device based on dichlorobenzonitrile synthesis and a use method thereof, and relates to the field of reaction devices.According to the technical scheme, the reaction device comprises a reaction tank and a cover located at the top end of the reaction tank, a heating interlayer is arranged on the reaction tank, and a spiral conveying pipe surrounding a reaction cavity in the middle of the reaction tank is arranged in the heating interlayer; the heating medium is conveyed through the spiral conveying pipe, and the gap between the heating interlayer and the spiral conveying pipe is filled with the heat preservation material, so that the heating medium is conveyed around the reaction cavity in the heating interlayer through the spiral conveying pipe, and the spirally distributed conveying pipe can enable the heating medium to uniformly act on the outer wall of the reaction cavity; heat loss is reduced through the heat preservation material between the heating interlayer and the spiral conveying pipe, accurate control and uniform distribution of the reaction temperature are achieved, side reactions caused by local overheating are avoided, and therefore generation of polychlorinated impurities is reduced, and the purity of the dichlorobenzonitrile product is improved.

The invention belongs to the technical field of polyfluorosiloxane synthesis, and provides a low-by-product polyfluorosiloxane controllable synthesis method which comprises the following steps: carrying out anionic ring opening polymerization on D3F by adopting a binary organic catalytic system, weakening the strong nucleophilicity of an active center based on hydrogen-bond interaction and steric effect, and inhibiting the occurrence of chain back-biting side reaction, so as to obtain the low-by-product polyfluorosiloxane. The polyfluorosiloxane with low content of by-product DnF (n is greater than or equal to 4), controllable structure and narrow molecular weight distribution is prepared. The polyfluorosiloxane with low byproduct content is catalyzed by the binary organic catalyst, the synthesis method is simple, the operation is convenient, the reaction condition is mild, the catalyst has good stability, large-scale production is easy, and further development of the polyfluorosiloxane in the field of high-end and harsh oil-resistant sealing materials can be promoted.

The invention relates to the technical field of aerogel, in particular to flexible flame-retardant aerogel and a preparation method thereof.The flexible flame-retardant aerogel is prepared from modified graphene, modified polyvinyl alcohol, silver nanowires, phytic acid and epoxy resin E-51; the furan group is introduced into the aerogel through the modified graphene, the furan group and the maleimide group are subjected to a D-A reaction, an adhesive is prevented from being used when the aerogel is bonded with a screen backboard, the D-A reaction is reversible, and lossless reworking can be realized. PVA and epoxy resin E-51 are added together, so that the heat resistance and mechanical strength of the material are improved. PVA is grafted with a large-steric-hindrance amine group, weak interaction with a furan group is generated, side reaction with an epoxy group of epoxy resin E-51 is avoided, and when aerogel is bonded to an OLED screen backboard, the protective layer is reversibly released, so that D-A reaction can be smoothly carried out. The hydrophobic treatment of the modified graphene and the modified grafting of the polyethylene to the mPEG can effectively improve the agglomeration of the modified graphene and ensure the uniform dispersion of the modified graphene.

The invention relates to the technical field of synthesis of a polymerization inhibitor DNBP, in particular to an efficient production method of the polymerization inhibitor DNBP, which comprises the following steps: step 1, material preparation: selecting corresponding raw materials, weighing and classifying the raw materials, and dividing the raw materials into three main materials, auxiliary materials and additives, the auxiliary material comprises a sulfonic acid type ion exchange resin catalyst, the additive is an ethanol-water mixed solvent, and during weighing, weighing and proportioning are performed according to the molar ratio of nitric acid to o-tert-butylphenol being 2.15: 1 and the mass ratio of o-tert-butylphenol to carbon tetrachloride being 0.15: 1; according to the method, a gradient temperature control strategy is adopted, and a multi-stage microchannel reactor is combined, so that efficient mass and heat transfer of nitration reaction is realized, deep nitration side reaction is inhibited, the content of dinitro isomer impurities is greatly reduced, meanwhile, the total residence time can be accurately controlled, the explosion risk caused by local overheating in a traditional process is avoided, and the method is suitable for industrial production. The reaction selectivity and the safety are obviously improved.

The invention relates to a preparation method of a silicon-carbon negative electrode material capable of reducing interface side reaction, which comprises the following steps: (S1) carrying out chemical vapor deposition on porous carbon by using organic silicon source gas to enable amorphous silicon to be attached in pores of the porous carbon to obtain a silicon-carbon composite material; and (S2) mixing a passivating agent with the silicon-carbon composite material, and then carrying out gradient heat treatment to obtain the silicon-carbon negative electrode material capable of reducing the interface side reaction, the passivating agent is compounded by ammonium carbonate and / or ammonium bicarbonate, C2-C8 aliphatic polybasic acid and organic salt of lithium according to the mass ratio of 1: (1.5-3): (0.8-1.5). All the components in the passivator cooperate with one another, surface amorphous silicon in porous carbon is partially passivated to form a uniform and compact passivation layer, and a small amount of carbon coating layers coating the surface of the porous carbon are formed in the passivation process, so that the interface side reaction of the material is obviously reduced.

The invention discloses an omariglitazone intermediate as well as a synthesis method and application thereof, and belongs to the technical field of pharmaceutical chemistry synthesis. The invention provides a synthesis method of an omarigliflozin intermediate and application of the intermediate in synthesis of omarigliflozin. The key of the synthesis method provided by the invention lies in the deprotection process of polycyclic indole amide, nitrile groups are not hydrolyzed, indole carboxylic acid is generated with high selectivity, molecular lactamization is avoided in the condensation process with polycyclic imine B, and expensive amidation reagents such as HATU are not needed in the process, so that the synthesis method is simple and easy to implement. And the purpose of preparing omariglitazone with low cost and high yield is achieved. The synthesis method has the advantages of easily available raw materials, mild reaction conditions, small side reaction influence, simplicity and convenience in operation and high yield, improves the yield, is easy to purify, and is suitable for industrial production of omariglitazone.

The invention provides a bio-based 1, 4-butanediol composition as well as a preparation method and application thereof, and the bio-based 1, 4-butanediol composition comprises bio-based 1, 4-butanediol, 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether. The total mass content of 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether in the bio-based 1, 4-butanediol composition is 51 to 220 ppm. The bio-based 1, 4-butanediol composition has low hygroscopicity, and can maintain low water content after long-term storage; meanwhile, when the bio-based 1, 4-butanediol composition is used for polyester synthesis, the esterification time can be shortened, the reaction efficiency can be improved, side reactions can be reduced, and a polyester product with better damp-heat resistance stability can be obtained.

The invention relates to the field of fine chemical engineering, and discloses a green process for preparing chloramine T by a continuous flow reactor. The method comprises the following steps: respectively pumping p-toluenesulfonamide, a sodium hydroxide solution and a sodium hypochlorite solution into a micro-channel mixer for instantaneous mixing, and carrying out chlorination reaction in a multi-stage temperature control tubular reaction unit; the concentration of free chlorine is detected on line at an outlet, and the flow rate of a chlorine source is dynamically adjusted through a PID algorithm, so that closed-loop control is realized; the reaction liquid is directly crystallized and separated to obtain the product without alkali wash. The system comprises a base solution and chlorine source conveying subsystem, a micro-channel mixer, a multi-stage reaction unit, an online monitoring module, a central controller and a crystallization unit. The side reaction is inhibited from the source, so that the free chlorine is less than or equal to 0.5 mg / L, the alkali washing step is omitted, the COD (Chemical Oxygen Demand) of the wastewater is reduced by more than 80%, the product purity is more than or equal to 99.5%, and the productivity is improved by 3 times.

A positive electrode material coated with a composite oxide, a preparation method therefor, and the use thereof. The positive electrode material comprises an inner core and a coating layer on the surface of the inner core; the chemical general formula for the inner core is: NabNixFeyMnzM1-x-y-zO2, wherein 0.4 ≤ b ≤ 1.2, 0.10 ≤ x ≤ 0.50, 0.10 ≤ y ≤ 0.50, 0.10 ≤ z ≤ 0.50; the coating layer comprises a composite oxide, and the composite oxide comprises two or more metal elements. The positive electrode material is coated with the composite oxide, which significantly improves the conductivity and stability of the positive electrode material, reduces contact between the positive electrode material and an electrolyte, inhibits the occurrence of side reactions, and improves the cycle performance of the material.

The invention discloses a carbon-based catalyst and a preparation method and application thereof to isomerization of glucose into fructose, the catalyst comprises an active component loaded on a carbon-based catalyst carrier and a chelating agent complexed with the active component, metal salts in the active component are Mg and K, the chelating agent is one or more of citric acid, triacetic acid, triethylamine ethylenediamine and potassium sodium tartrate. The chelating agent adjusts alkali active sites of a reaction system through acidic functional groups of the chelating agent, maintains an acid-base environment required by the reaction, and promotes an isomerization reaction from glucose to fructose. Meanwhile, the chelating agent and the metal ions form a stable complex to prevent metal salt from inactivation, and the metal ions are ensured to be uniformly distributed on the surface of the carrier and prevented from being agglomerated through the dispersity of the chelating agent, so that the activity and stability of the catalyst are improved. By controlling the dosage of the chelating agent and coordination of metal ions, the selectivity of the glucose isomerization reaction and the fructose yield are effectively improved, side reactions are inhibited, and the overall efficiency of the reaction is remarkably improved.

The invention discloses electronic-grade amine epoxy resin and a preparation method thereof, and belongs to the field of epoxy resin preparation. Aiming at the problems of more by-products and poor performance of the existing epoxy resin preparation, the invention provides the preparation method of the electronic-grade amine epoxy resin, which comprises the following steps: synthesizing a chlorohydrin ether intermediate from p-aminophenol and epichlorohydrin; meanwhile, a catalyst is added in the ring-opening reaction stage; carrying out removal of epoxy chloropropane; alkali metal hydroxide is added for a dehydrochlorination reaction, and a target product is generated in a closed-loop manner; and washing to remove excessive alkali metal hydroxides, and reacting to generate chlorides to obtain the electronic-grade amine epoxy resin. According to the method, the ring opening speed of phenolic hydroxyl is remarkably increased through the catalyst, so that epoxy chloropropane is fully reacted, and residues are reduced; according to the method, excessive epoxy chloropropane is removed, so that side reaction of epoxy chloropropane in a ring closing stage is avoided, generation of by-products is reduced to the greatest extent, operation is simple, and high-quality epoxy resin can be generated.

The invention discloses an electrolyte of an aqueous zinc-iodine battery, and relates to the technical field of zinc-iodine batteries, the electrolyte is prepared from an I + stabilizer, a hydrogen bond ligand, a low-freezing-point hydrogen donor solvent and a zinc salt, and the molar ratio of the I + stabilizer to the hydrogen bond ligand to the low-freezing-point hydrogen donor solvent to the zinc salt is 1: 0.5: 5: 0.5-1.5. The invention also provides a preparation method of the electrolyte and a zinc-iodine battery prepared by using the electrolyte. The zinc-iodine battery constructed by the invention can realize highly reversible I- / I2 / I + conversion and rapid iodide conversion kinetics in a wide temperature range of-25 DEG C to 40 DEG C, and has high energy density and excellent long cycle stability. In addition, due to the unique solvation structure of the electrolyte, the activity of water molecules in the system is reduced, and then the hydrogen evolution reaction and other side reactions are inhibited. Therefore, the invention provides a feasible strategy for realizing wide temperature range, high capacity and high performance of the zinc-iodine battery.

The invention provides a CoCe-SNC catalyst and a preparation method and application thereof, and belongs to the technical field of hydrogen fuel cell / metal air cell cathode catalysts. The preparation method comprises the following steps: mixing and grinding a metal organic framework ZIF-8 and KSCN, carrying out first pyrolysis, compounding the obtained nitrogen and sulfur-containing co-doped carbon with two metal complexes Co-PM and Ce-PM, and carrying out second pyrolysis to obtain the CoCe-SNC diatomic catalyst. According to the invention, the two-dimensional lamellar structure carbon material and the asymmetric coordination diatomic metal are compounded, so that the catalytic performance of the whole catalyst is improved, and meanwhile, the yield of hydrogen peroxide generated by side reaction is reduced. The catalyst is applied to a hydrogen fuel cell / metal air cell, and the defects that in the prior art, a noble metal catalyst is high in cost, and a non-noble metal catalyst is low in catalytic activity, high in hydrogen peroxide yield, poor in catalyst stability and the like are overcome.

The present invention discloses a method for preparing enol by selective hydrogenation of alkynol. By adding an acidic substance to adjust the pH value of the reaction system and adding crown ether to inhibit the two main side reactions of self-coupling and over-hydrogenation of terminal alkyne, the purpose of improving low selectivity is achieved. The product has a pure odor and mild reaction conditions.

The utility model provides a hydrogenation reaction system for producing sulfur by reducing acid gas regenerated by activated carbon, which comprises an acid gas pretreatment system, a first-stage hydrogenation system, a second-stage hydrogenation system, a tail gas treatment system and a liquid sulfur tank, the acid gas generated by regeneration of desulfurized activated carbon is pretreated and then is subjected to hydrogenation reduction to produce sulfur, the hydrogenation is divided into two stages, wherein the primary hydrogenation is divided into a plurality of sections according to different SO2 contents, a sectional hydrogenation method is adopted, gas subjected to the primary hydrogenation enters the secondary hydrogenation, air is introduced into the gas subjected to the secondary hydrogenation, and after side reaction products generated by hydrogenation are oxidized into sulfur and SO2, residual tail gas is sent back to an inlet of the activated carbon desulfurization device. Through first-stage hydrogenation and second-stage hydrogenation, the temperature rise of the hydrogenation reaction is reduced, side reactions are reduced, and the SO2 conversion rate is improved; oxidation-method tail gas treatment is adopted to directly return to activated carbon for desulfurization, and no waste gas is discharged on the whole.

The invention belongs to the field of polymer synthesis, and discloses a preparation method of poly (delta-thiovalerolactone), which comprises the following step: in an organic solvent, in the presence of a main catalyst and an aryl mercaptan initiator, carrying out polymerization reaction on a compound as shown in a formula (II) at 0-80 DEG C, according to the preparation method disclosed by the invention, side reactions in a polymerization process are effectively reduced, so that a monomer can be converted into poly delta-thiovalerolactone at a high conversion rate. Compared with the prior art, the high-molecular-weight poly (delta-thiovalerolactone) is obtained, and the mechanical property of the polymer can be remarkably improved due to the improvement of the molecular weight.