68results about "Preparation by dehydrogenation" patented technology

The invention discloses application of a supported heterogeneous catalyst of oxide and copper-manganese spinel in preparation of acetaldehyde by anaerobic dehydrogenation of ethanol, and belongs to the technical field of heterogeneous catalysis for preparation of acetaldehyde and hydrogen by anaerobic dehydrogenation of ethanol. The reaction is carried out in a fixed bed reactor, under the conditions that the reaction atmosphere is nitrogen, the reaction temperature is 280 DEG C and the mass space velocity is 66.1 h <-1 >, the ethanol conversion rate is 72.5%, the acetaldehyde selectivity is 95.0%, and the space time yield of acetaldehyde based on the copper-manganese composite oxide is 43.5 h <-1 >, so that high-selectivity preparation of acetaldehyde and hydrogen under relatively mild conditions is realized; the system has the remarkable advantages of simple catalyst preparation, high catalytic activity under the condition of high mass airspeed, high space-time yield of acetaldehyde, high atom utilization rate of the system, good stability and the like. The CuMnTi-1 catalyst can be stabilized for more than 70 hours, the CuMnTi-1 improves the utilization rate of copper and manganese, improves the catalytic performance, reduces the demand quantity of copper-manganese spinel in the reaction, and reduces the overall cost of catalyst preparation.

The invention discloses a copper-based catalyst for preparing acetaldehyde through ethanol dehydrogenation as well as a preparation method and application of the copper-based catalyst. The preparation method comprises the following steps: S1, carrying out alkalization treatment on protic mordenite in a strong alkali solution to increase the number of surface hydroxyl groups of the protic mordenite; and S2, adding the mordenite obtained in the step S1 into a copper salt solution to load copper ions, and then sequentially carrying out low-temperature drying shaping and medium-temperature activation stages to obtain the copper-based catalyst with networked Cu-OH-Si-O bonds on the surface. Through the synergistic effect of alkali liquor regulation and control and staged oxygen roasting, the dispersity and stability of a Cu active center in the catalyst are improved, the acetaldehyde selectivity of the reaction of preparing acetaldehyde through ethanol dehydrogenation is also improved, and side reactions are inhibited. Carrying out heat treatment regeneration on the inactivated copper-based catalyst in an oxygen-containing atmosphere; and after regeneration, the networked Cu-OH-Si-O bond on the surface of the copper-based catalyst is reconstructed.

The invention relates to a catalyst for preparing cyclododecanone through cyclododecanol dehydrogenation and a preparation method and application thereof. The catalyst component comprises copper, zinc, zirconium, sodium, calcium, aluminum and iron; the catalyst is prepared from the following components in percentage by mass in an oxide form: 40 to 65 weight percent of copper oxide, 10 to 21 weight percent of zinc oxide, 10 to 30 weight percent of zirconium oxide, 5 to 20 weight percent of sodium oxide, 1 to 5 weight percent of calcium oxide, 0.5 to 1.5 weight percent of aluminum oxide and 0.05 to 0.5 weight percent of iron oxide. In one embodiment, according to the preparation method of the catalyst provided by the invention, water vapor is added during roasting in a nitrogen environment, so that the release speed of carbon dioxide is controlled, and formation of carbon deposition in the roasting process is reduced. The catalyst can solve the problem of low selectivity caused by low dehydrogenation reaction conversion rate and many by-product cyclododecene, and has the characteristics of high strength, good hydrothermal resistance, long service life and the like.

Disclosed herein is a method for converting ethanol to 1,3-butadiene, wherein the method utilizes H2 produced during a first step of the method for subsequent conversions involved in the method. In particular aspects, H2 produced from converting ethanol to acetaldehyde is used to promote the conversion of the acetaldehyde to 1,3-butadiene. The H2 promotes enhanced catalyst stability, as well as enhanced selectivity and yields of the 1,3-butadiene product. In particular aspects, the method comprises two steps to produce the 1,3-butadiene from the ethanol and H2 produced from a first step facilitates enhanced selectivities and yields for the second step.

This invention discloses the application of an oxide-coated copper-manganese spinel supported heterogeneous catalyst in the oxygen-free dehydrogenation of ethanol to acetaldehyde, belonging to the field of heterogeneous catalysis technology for the oxygen-free dehydrogenation of ethanol to acetaldehyde and hydrogen production. The reaction is carried out in a fixed-bed reactor under a nitrogen atmosphere at a temperature of 280°C and a mass hourly space velocity (WHSV) of 66.1 h⁻¹. ‑1 Under the given conditions, the ethanol conversion rate was 72.5%, the acetaldehyde selectivity was 95.0%, and the space-time yield of acetaldehyde based on copper-manganese composite oxides was 43.5 h⁻¹. ‑1 This invention achieves highly selective preparation of acetaldehyde and hydrogen under relatively mild conditions. The system possesses significant advantages, including simple catalyst preparation, high catalytic activity under high mass space velocity (MHSV) conditions, high MHSV yield of acetaldehyde, high atom utilization, and good stability. The CuMnTi-1 catalyst of this invention remains stable for over 70 hours. CuMnTi-1 improves the utilization rate of copper and manganese, enhances catalytic performance, reduces the amount of copper-manganese spinel required in the reaction, and lowers the overall cost of catalyst preparation.

The application discloses an oxide-sulfide S-type heterojunction composite photocatalyst as well as a preparation method and application thereof. x The oxide-sulfide S-type heterojunction composite photocatalyst is prepared by adding WO x into ethanol, uniformly ultrasonic dispersing, and then performing heating and dry distillation. The application successfully constructs a tungsten oxide and cadmium sulfide heterojunction, has good light response, utilizes a heterojunction interface formed by the two catalysts and having a synergistic effect, improves the photocatalytic hydrogen production capacity, and promotes selective oxidation of benzyl alcohol. The application has simple operation and good repeatability.

The invention belongs to the field of photocatalysis, and particularly discloses a perovskite composite photocatalyst for photocatalytic ethanol dehydrogenation and application. The composite photocatalyst takes a CdS nanorod as a carrier, a Cs2AgBiBr6 double perovskite active component formed by CsBr, AgBr and BiBr3 precursors is loaded on the surface of the CdS nanorod through a vacuum in-situ growth method, and a Pt, Rh or Ni metal cocatalyst can be further loaded. The method comprises the following steps: dispersing a CdS nanorod and a perovskite precursor in a mixed organic solvent, carrying out vacuum freezing-air exhaust circulation treatment, and removing the solvent under a heating condition to prepare the composite photocatalyst. When the photocatalyst is used for an ethanol photocatalytic dehydrogenation reaction under an anaerobic condition, hydrogen, acetaldehyde and acetal can be efficiently generated under the irradiation of visible light. According to the method, the photo-generated charge separation efficiency and the reaction stability are remarkably improved, and a new way is provided for ethanol high-valued conversion.

The present application provides a kind of hydroxyl dehydrogenation preparation aldehyde or ketone dehydrogenation catalyst and its preparation method.The present application reduces the acidity of catalyst by introducing Li adjuvant, reduces the generation of by-product heavy oil.By reacting Li with silicon source to generate lithium silicate, Li is fixed, and by adding condensed aluminum phosphate to fix lithium silicate, the loss of lithium silicate is inhibited.By using water vapor hydrothermal treatment of catalyst at different temperatures, the pore of catalyst can be effectively enlarged, the mass transfer effect in the reaction process is improved, and the catalyst can have better dehydrogenation activity at low temperature.The catalyst prepared by the method described in the present application can achieve high activity at a lower temperature, the production of by-products is inhibited by adding alkaline adjuvant, and the alkaline adjuvant is effectively immobilized by adding solidifying agent, to improve the operating stability of the catalyst.

The present invention concerns a process for utilizing waste streams from an oxo synthesis plant by gasification and an oxo process plant comprising the necessary units for oxo synthesis and at least one gasifier G. The process comprises a conversion of a waste stream W1 purged from the alcohol upgrading unit ALUU and optionally also of a waste stream W2 purged from a hydroformylation reaction unit HRU. The conversion by a gasification process in at least one gasifier G results in synthesis gas which can then be utilized e.g., for as a feedstock for an oxo process or production of other chemicals in another chemical production plant.

To provide a fluorine-containing ether compound that can form a surface layer that excels in durability and a method of manufacturing the same, a fluorine-containing ether composition and a coating liquid, and an article having a surface layer that excels in durability and a method of manufacturing the same.SOLUTION: A fluorine-containing ether compound is expressed by the following formula (A1) or (A2). Formula (A1): {RfO-(Rf1O)m1-(R1)m2-(CHF)m3-O-(CHF)m4}n1-Q1(-T1)n2. Formula (A2): (T2)n3-Q2-(CHF)m5-O-(CHF)m6-(R2)m7-O-(Rf2O)m8-(R3)m9-(CHF)m10-O-(CHF)m11-Q3(-T3)n4, provided that the symbols in the formulas are as described in the specification.SELECTED DRAWING: Figure 1

This invention provides a supported Cu catalyst, its preparation method, and a method for preparing methyl ethyl ketone (MEK). The catalyst has the structural formula Cu-ZnAl-LDO, and the molar ratio of Cu, Zn, and Al in the catalyst is (1-4):(1-3):(1-3). The active centers of the catalyst are Cu nanoparticles rich in surface defects, with a particle size of 3-6 nm. Based on the total mass of the catalyst, the Cu loading of the active centers is 24-30 wt% (based on metal element content). The surface defects are composed of Cu nanoparticles, and the surface defect content is 52-70% based on the surface area of ​​the Cu nanoparticles. This invention achieves a uniform and stable distribution of the active center Cu nanoparticles on the support surface by employing specific material ratios and preparation methods. By controlling the crystal structure and surface electron distribution, it prevents the aggregation and deactivation of nanoparticles during high-temperature and long-term reactions, significantly improving the catalyst's stability and extending its service life.

The invention provides a method for treating a phenol hydrogenation byproduct. The method comprises the following steps: obtaining a byproduct heavy component generated in a phenol hydrogenation process; carrying out catalytic hydrogenation reaction on the byproduct heavy component to generate an intermediate product; carrying out fracture reaction on the intermediate product to generate a first target product; carrying out dehydrogenation reaction on the first target product to generate a second target product; and separating and purifying the second target product to obtain a final product.

The present invention relates to a method for the dehydrogenation of a feedstock containing ethanol, using at least one multi-tubular reactor, which advantageously comprises a plurality of tubes containing at least one dehydrogenation catalyst and a calender, wherein the feedstock is introduced into the tubes in gaseous form, the inlet temperature being greater than or equal to 240°C, the pressure being between 0.1 and 1.0 MPa, and the WWH being between 2 and 15 h. -1 wherein the heat transfer fluid flows through the calender at a flow rate such that the weight ratio of the heat transfer fluid relative to the feedstock is 1.0 or greater, and the heat transfer fluid is introduced into the calender in gas form at an inlet temperature of 260°C or greater and an inlet pressure of 0.10 MPa or greater and 1.10 MPa or less, and exits the calender at least partially in liquid form.

A method for producing a nano-Pd catalyst supported on a nitrogen-doped hierarchical porous carbon, characterized in that it comprises: 1) Preparation of a nitrogen-doped hierarchical porous carbon, 2) Mixing the nitrogen-doped hierarchical porous carbon produced in step 1) with water and adjusting the pH of the mixed solution to alkaline. 3) Mixing the mixture solution prepared in step 2) with the aqueous solution of Pd metal precursors, adding reducing agent and obtaining the nano-Pd catalyst supported on the nitrogen-doped hierarchical porous carbon after reduction.

The invention belongs to the technical field of organic synthesis, and particularly discloses a synthesis method of isopinopinone, which comprises the following steps: (1) by taking alpha-pinene as a raw material, hydroborating by using a borane tetrahydrofuran complex, and oxidizing the hydroboration product by using a sodium hydroxide solution and hydrogen peroxide to obtain isopinopinol; (2) performing high-temperature dehydrogenation on the isopinopinol by taking Cu / Ni-Al-SBA-15 as a catalyst to obtain a product, namely isopinopinone; the total loading capacity of Cu and Ni in the Cu / Ni-Al-SBA-15 is 9-12%, the molar ratio of Cu to Ni is (8-10): 1, and the molar ratio of Si to Al in the carrier Al-SBA-15 is (9-11): 1. The conversion rate and the yield of the two-step reaction are relatively high, the dehydrogenation catalyst in the second step can be recycled for more than three times through filtration, and compared with a traditional copper-silicon catalyst, the mesoporous weak-acid molecular sieve serving as a carrier can effectively improve the product selectivity. The purity of the isopinopinone obtained through filtration and rectification can reach 99% or above, the cost can be effectively reduced, and industrial production can be achieved.

The invention belongs to the technical field of catalysts. The invention provides a catalyst for preparing cyclopentanone through cyclopentanol dehydrogenation and a preparation method thereof.The preparation method comprises the steps that S1, 120-126 g of potassium pyrophosphate, 10-13 g of stannous chloride, 8-10 g of copper sulfate and 2-3 g of carbon nano tube powder are added into 1 L of deionized water, the pH value is adjusted to 7-8, and an electroplating solution is obtained; s2, assembling a PS colloidal crystal template on the pretreated copper sheet to obtain a copper sheet with the PS colloidal crystal template; s3, taking a copper sheet with the PS colloidal crystal template as a cathode and a titanium mesh as an anode, performing electro-deposition in the electroplating solution, roasting at 500-550 DEG C for 3-4 hours, stripping and grinding to obtain a Sn-Cu-CNT composite material; s4, etching the Sn-Cu-CNT composite material with 10vol% acetic acid for 30-35 minutes in an ice bath at 0-5 DEG C to obtain an etched material, putting the etched material into an ammonia water-EDTA (Ethylene Diamine Tetraacetic Acid) mixed solution with the pH (Potential of Hydrogen) of 9.5, and oscillating for 10 minutes at 60 DEG C to obtain a carrier; and S5, impregnating the carrier with a nickel nitrate solution, drying, and roasting to obtain the catalyst. The method can effectively improve the conversion rate of cyclopentanol and the selectivity of cyclopentanone.

The invention relates to a copper monatomic loaded titanium dioxide / elemental titanium heterojunction as well as a preparation method and application of the copper monatomic loaded titanium dioxide / elemental titanium heterojunction. The heterojunction comprises elemental titanium, titanium dioxide and copper single atoms, the elemental titanium and the titanium dioxide form a heterojunction, and the copper single atoms are loaded on the titanium dioxide component in the heterojunction; in the preparation method, metal elementary substance titanium is directly used as a raw material, direct oxidation of part of titanium species is achieved by accurately controlling the calcination temperature and calcination time, and then the dispersion state of loaded copper species is ensured by controlling the mass ratio of a soluble copper source to titanium dioxide / elementary substance titanium heterojunction; and finally obtaining the copper monatomic loaded titanium dioxide / elemental titanium heterojunction photocatalyst. The copper monatomic loaded titanium dioxide / elemental titanium heterojunction prepared by the preparation method disclosed by the invention has relatively excellent photocatalytic methanol reforming reaction performance.

Disclosed herein are processes for preparing certain intermediates useful in the synthesis of 3-fluoro-5-(((1S,2aR)-1,3,3,4,4-pentafluoro-2a-hydroxy-2,2a,3,4-tetrahydro-1H-cyclopenta[cd]inden-7-yl)oxy)benzonitrile or a pharmaceutically acceptable salt thereof.

The application discloses a preparation method of a copper-based catalyst, the copper-based catalyst and application thereof, and belongs to the technical field of bioenergy and chemical industry. The method comprises the following steps: obtaining a precursor I; the precursor I comprises a carrier and a supported active component, the active component contains copper elements, and the carrier is a molecular sieve with a silicon-aluminum ratio greater than 200; the precursor I is subjected to silicon component coating treatment to obtain a precursor II; the precursor II is calcined and reduced to obtain the copper-based catalyst; the silicon component coating treatment comprises the following steps: obtaining a gel containing a silicon source I, a template agent I, a solvent I and the precursor I; and the gel is heated in water vapor to obtain the precursor II. The method has the advantages of simple operation, low catalyst cost, economy and practicability, high acetaldehyde production efficiency and low energy consumption.

The invention discloses a preparation method of a catalyst for preparing acetaldehyde from ethanol, and belongs to the technical field of chemical synthesis, and the method comprises the following steps: dissolving a metal salt in deionized water, adding a silicon source and a template agent, adjusting the pH value, atomizing the solution, and carrying out aerosol spray drying to form a catalyst precursor; immersing the precursor into a dopamine-Tris buffer solution, and performing in-situ polymerization to form a polydopamine shell layer; and performing high-temperature carbonization and hydrogen reduction to obtain the catalyst. The method comprises the following steps: adding a catalyst into a reaction tube, fixing in a fixed bed reactor, preheating ethanol, introducing into the fixed bed reactor, reacting on the surface of the catalyst to generate acetaldehyde and hydrogen, condensing and separating acetaldehyde, and collecting hydrogen through a gas device arranged at the outlet of the reactor. According to the invention, the problems of low acetaldehyde selectivity, easy sintering deactivation of the catalyst and the like in the prior art are solved, the acetaldehyde selectivity is effectively improved, and the service life of the catalyst is prolonged.

1. A process comprising: (a) providing a used tire feedstock; (b) gasifying the used tire feedstock to produce a gas stream comprising carbon monoxide, hydrogen, and carbon dioxide; (c) biosynthetically converting at least a portion of the carbon monoxide, hydrogen, and carbon dioxide in the gas stream to produce a first product stream; (d) converting at least a portion of the first product stream to a second product stream comprising acetaldehyde and hydrogen; (e) passing a portion of the hydrogen in the second product stream to the aforementioned step of biosynthetically converting at least a portion of the carbon monoxide, hydrogen, and carbon dioxide in the gas stream; and (f) converting at least a portion of the acetaldehyde to butadiene monomer.

The present application relates to the technical field of formaldehyde production, in particular to a kind of preparation of formaldehyde intelligent integrated evaporator, including evaporation conduction structure, first injection pipe, evaporation processing structure and second injection pipe, the lower end of evaporation conduction structure is communicated with evaporation processing structure, the upper end side of evaporation processing structure is communicated with first injection pipe, the side of evaporation processing structure away from first injection pipe is communicated with second injection pipe, evaporation processing structure includes butt joint pipe seat, sealed communication seat, evaporation heating part and butt joint valve seat, the lower end of butt joint pipe seat is fixedly connected with sealed communication seat, the center lower end of sealed communication seat is communicated with evaporation heating part, the lower end of evaporation heating part is equipped with butt joint valve seat, the center lower end of butt joint valve seat is communicated with discharge guide pipe, the lower end side of butt joint valve seat is fixedly connected with support stable seat. Through the setting of evaporation conduction structure and evaporation processing structure, the preparation evaporation processing of formaldehyde is realized.

The invention relates to a method and a device for preparing an anhydrous formaldehyde solution, and the process is as follows: methanol passes through a heat exchanger and a heater and then enters a dehydrogenation reactor, part of methanol is dehydrogenated to form synthesis gas containing methanol, formaldehyde and hydrogen at a certain temperature under the catalysis of a dehydrogenation catalyst, the synthesis gas is discharged from the top of the dehydrogenation reactor and enters a liquefaction tower, and under the action of the liquefaction tower, the synthesis gas is liquefied. Dissolving formaldehyde into a small amount of methanol to form an anhydrous formaldehyde solution, and discharging the anhydrous formaldehyde solution from the bottom of the liquefying tower for synthesizing DMMn; a gas phase is discharged from the top of the liquefying tower and enters a gas-liquid separation tower after being condensed, methanol obtained at the tower bottom is returned and reused, and crude hydrogen at the tower top enters a spraying absorption tower and is discharged from the tower top after being subjected to countercurrent absorption by an absorbent; the crude absorbent is discharged from the tower bottom and enters a desorption tower, methanol is discharged from the tower top of the desorption tower and recycled, the methanol is condensed and then returned for use, and the absorbent discharged from the bottom of the desorption tower is returned to the spray absorption tower to continuously participate in absorption; the device mainly comprises a dehydrogenation reactor, a liquefaction tower, a gas-liquid separation tower, an absorption tower and a desorption tower.

The application discloses a dehydrogenation catalyst and a precursor, a preparation method and application thereof. The dehydrogenation catalyst precursor is obtained through the following steps: mixing an aqueous solution of a precipitant and an aqueous solution of a metal salt to perform a precipitation reaction; and then performing post-treatment. The aqueous solution of the metal salt comprises a copper salt and a carrier alkaline earth metal salt. The temperature of the precipitation reaction is 30-90 DEG C. The end point pH value of the precipitation reaction is 6.0-10.0. The dehydrogenation catalyst precursor comprises an active component precursor and a carrier. The active component precursor is copper oxide. The carrier is one or more of alkaline earth metal oxides. The content of the copper oxide is 10%-75%. The content of the carrier is 5%-51%. The NH3 adsorption amount of the dehydrogenation catalyst precursor is less than 90 umol / g. The dehydrogenation catalyst obtained by reducing the dehydrogenation catalyst precursor is applied to a dehydrogenation reaction for preparing methyl isobutyl ketone. The temperature of the dehydrogenation reaction is 200-300 DEG C. The pressure of the dehydrogenation reaction is 0-0.5 MPa, and the dehydrogenation catalyst has high conversion rate and selectivity.

The present invention relates to a process for the chemical conversion (I) of ethanol and water to at least one functionalized low molecular weight hydrocarbon K, carbon dioxide and hydrogen, in which at least a portion of the carbon dioxide and / or hydrogen formed is separated from the product mixture (II) and fed to a fermentative reaction step (III) with which ethanol and / or at least one functionalized low molecular weight hydrocarbon K is produced, and subsequently any ethanol formed is fed to the chemical conversion (I) and any functionalized low molecular weight hydrocarbon K formed is combined with the product stream of the chemical conversion (I).

The invention discloses a magnesium-modified copper-based catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps that 1, a mixed aqueous solution is subjected to co-precipitation under the alkaline condition, a co-precipitation reaction system is obtained, and the mixed aqueous solution comprises a copper compound and a magnesium compound; the molar ratio of the copper compound to the magnesium compound is (15-40): 1; 2) performing chemical reduction on the coprecipitation reaction system in the presence of a reducing agent to obtain a catalyst precursor; and 3) carrying out an electrochemical reduction reaction on the catalyst precursor to obtain the magnesium-modified copper-based catalyst. When the catalyst is used for a carbon dioxide electroreduction reaction, the Faraday efficiency is obviously improved, the energy loss is small, and when the catalyst is used for a hydrogenation reaction and an anaerobic dehydrogenation reaction, the reaction conversion rate, the reaction selectivity and the stability are obviously improved.

The application discloses an oxide catalyst for preparing acetaldehyde and hydrogen through ethanol anaerobic dehydrogenation, a preparation method and application thereof, and belongs to the technical field of catalysts. The oxide catalyst for preparing acetaldehyde and hydrogen through ethanol anaerobic dehydrogenation is a single oxide or a composite oxide. The oxide catalyst component serves as a carrier or an active component. The oxide catalyst component contains two or three of zinc oxide, aluminum oxide, zirconium oxide and magnesium oxide. A reaction raw material is configured into a precursor solution according to a certain metal atom molar ratio. A precipitating agent is added dropwise into the solution under severe stirring to adjust the pH of the mixed solution. The mixture is stirred and aged to obtain an intermediate material. The intermediate material is filtered, dried and ground to obtain a powder. The powder is calcined in a muffle furnace to obtain the catalyst. The catalyst has the advantages of convenient operation, improved production efficiency, reduced cost, green environmental protection and sustainable development.

The invention discloses preparation and application of a catalyst for preparing acetaldehyde through ethylene glycol dehydration, and belongs to the technical field of chemical engineering. The catalyst is an acidic molecular sieve, and the molecular sieve is selected from one or a combination of more than two of molecular sieves of which the structure types are MWW, FER, MFI, MOR, FAU and BEA; the molecular sieve is prepared by sequentially carrying out organic ammonium salt exchange, acidic molecule loading and ammonium ion exchange and then roasting. The catalyst disclosed by the invention is mild in catalytic condition, simple in preparation process, easy to industrially amplify and easy to recycle, has relatively high catalytic activity in the process of preparing acetaldehyde by dehydrating ethylene glycol, and has a very good application prospect.

The invention discloses a method for preparing acetaldehyde from ethanol, which comprises the following steps: mixing Cu (NO3) 2, Zn (NO3) 2 and Al (NO3) 3 solutions to obtain a mixed solution, adding the mixed solution and Na2CO3 into a reaction kettle in a parallel flow manner, aging, washing to be neutral, drying to obtain a Cu-Zn-Al precursor, dipping the Cu-Zn-Al precursor into a Ce (NO3) 3 solution, transferring to a hydrothermal kettle for high-temperature reaction, roasting in a muffle furnace to generate a Cu-ZnO-Al2O3-CeO2 composite catalyst with a multi-stage pore structure, and drying to obtain the acetaldehyde. Tabletting and molding for later use; ethanol is used as a raw material, and the Cu-ZnO-Al2O3-coated CeO2 composite catalyst with the hierarchical porous structure is used for catalyzing ethanol to prepare acetaldehyde, so that the conversion rate of ethanol and the selectivity of acetaldehyde are improved, and the service life of the catalyst is prolonged.

The invention discloses a method for preparing glyoxal through ethylene glycol dehydrogenation, and belongs to the technical field of glyoxal preparation. According to the method, liquid-phase ethylene glycol is subjected to catalytic dehydrogenation under the catalytic action of a supported copper catalyst at the reaction temperature of 150-240 DEG C and the reaction pressure of 0.001-0.2 MPa to generate glyoxal and hydrogen, the supported copper catalyst is composed of an active component Cu, an auxiliary and a carrier, the reaction process for preparing glyoxal through ethylene glycol dehydrogenation is simple, the reaction belongs to an endothermic reaction, and the method is suitable for industrial production. The reaction temperature is relatively low, the energy consumption is low, the reaction safety is high, the glyoxal selectivity is high, high-purity hydrogen can be produced, less three wastes are produced, and the method has a relatively high industrial application value.