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CN-122006816-A - Mercury-free catalyst and preparation method and application thereof

CN122006816ACN 122006816 ACN122006816 ACN 122006816ACN-122006816-A

Abstract

The invention relates to the technical field of catalyst preparation, in particular to a mercury-free catalyst and a preparation method and application thereof. The preparation method of the mercury-free catalyst comprises the following steps of adding copper salt, active auxiliary agent and iridium complex into ethanol to obtain a mixed solution, then adopting an isovolumetric impregnation method to impregnate the mixed solution into pretreated active carbon, standing and drying to obtain the mercury-free catalyst. The preparation method has the advantages of simple steps, easy operation, high catalytic activity, good stability, long service life, no mercury, environmental protection and the like.

Inventors

  • SONG YANFEN
  • SHI PIAN
  • CHEN WEIWEN
  • HE ZHI
  • ZHENG LING

Assignees

  • 湖北海力环保科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. A method for preparing a mercury-free catalyst, comprising the steps of: adding copper salt, active auxiliary agent and iridium complex into ethanol to obtain a mixed solution, then adopting an equal volume impregnation method to impregnate the mixed solution into pretreated active carbon, standing and drying to obtain the mercury-free catalyst; The structural formula of the active auxiliary agent is as follows: 。
  2. 2. The method for preparing the mercury-free catalyst according to claim 1, wherein the preparation method of the active auxiliary agent comprises the following steps: Under the protection of inert gas, octamethyl silsesquioxane, N-allyl-1, 8-naphthyridine-2-formamide and a platinum catalyst are added into 1, 4-dioxane, and the active auxiliary agent is prepared after the reaction.
  3. 3. The method for preparing the mercury-free catalyst according to claim 2, wherein the dosage ratio of the octamethyl silsesquioxane to the N-allyl-1, 8-naphthyridine-2-formamide to the platinum catalyst is 1mol (4-4.1) mol (5-6) mL, the platinum catalyst is platinum (0) -1, 3-divinyl-1, 3-tetramethyl disiloxane, and the reaction temperature is 80-90 ℃ and the reaction time is 12-24h.
  4. 4. The method for preparing a mercury-free catalyst according to claim 1, wherein the iridium complex is prepared by the following steps: (1) Adding 2- (4-bromomethylphenyl) pyridine into tetrahydrofuran, and then adding hexadecyldimethyl tertiary amine, and reacting to obtain a compound 1; the structural formula of the compound 1 is as follows: (2) Adding triethylamine and acetone [ bis- (2-aminoethyl) dithioketal ] into tetrahydrofuran, and then adding a tetrahydrofuran solution of 2, 2-bipyridine-4, 4-diformyl chloride to react to prepare a compound 2; the structural formula of the compound 2 is as follows: (3) Adding the compound 1, the compound 2 and iridium trichloride hydrate into ethylene glycol diethyl ether, and carrying out reflux reaction under the protection of inert gas to obtain an iridium compound; The iridium complex has the structural formula: 。
  5. 5. The method for preparing the mercury-free catalyst according to claim 4, wherein the molar ratio of 2- (4-bromomethylphenyl) pyridine to hexadecyldimethyl tertiary amine in the step (1) is 1 (2.5-3.8), the reaction time is 36-48h, the dosage ratio of 2, 2-bipyridine-4, 4-dicarboxyl chloride, acetone [ bis- (2-aminoethyl) dithioketal ] and triethylamine in the step (2) is 1mmol (2-2.5) mmol (8-10) mu L, and the concentration of the tetrahydrofuran solution of 2-bipyridine-4, 4-dicarboxyl chloride is 0.9-1mol/L.
  6. 6. The method for preparing the mercury-free catalyst according to claim 4, wherein the molar ratio of the compound 1 to the compound 2 to the iridium trichloride hydrate in the step (3) is 1 (0.56-0.64): 0.4-0.48), and the reflux reaction time is 36-48 hours.
  7. 7. The method for preparing the mercury-free catalyst according to claim 1, wherein the preparation method of the pretreated activated carbon comprises the following steps: and (3) soaking the activated carbon in a hydrochloric acid solution, washing and drying to obtain the pretreated activated carbon.
  8. 8. The preparation method of the mercury-free catalyst according to claim 1, wherein the copper salt is cupric chloride, the copper salt accounts for 5-15% of the mercury-free catalyst, the active auxiliary agent accounts for 2-5% of the mercury-free catalyst, and the iridium complex accounts for 0.5-3% of the mercury-free catalyst.
  9. 9. A mercury-free catalyst prepared by the method of any one of claims 1-8.
  10. 10. The use of a mercury-free catalyst as claimed in claim 9, for the preparation of vinyl chloride by hydrochlorination of acetylene.

Description

Mercury-free catalyst and preparation method and application thereof Technical Field The invention relates to the technical field of catalyst preparation, in particular to a mercury-free catalyst and a preparation method and application thereof. Background Vinyl chloride monomer is the main raw material for producing polyvinyl chloride, and the production process mainly comprises an ethylene method and an acetylene method. In industrial applications of acetylene to vinyl chloride, conventionally used mercury chloride catalysts have been limited and eliminated due to their high toxicity and environmental hazards. Therefore, the development of efficient and environmentally friendly mercury-free catalysts is an important direction of current research. Copper-based catalysts are considered to be viable alternatives to mercury chloride catalysts due to their better catalytic activity and relatively low environmental toxicity. However, the current copper-based catalysts generally have the problem of higher copper loadings, and the copper loadings of some catalysts can even reach above 20 wt%. Although copper is less toxic than mercury, there is still some environmental risk as a heavy metal. In addition, the active carbon carrier is easy to generate carbon deposition phenomenon in long-term reaction, and further affects the stability and service life of the catalyst. Therefore, how to reduce the copper load and simultaneously maintain or even improve the catalytic performance becomes a key problem to be solved in the industrial application of the copper-based catalyst. Disclosure of Invention In order to overcome the defects of the prior art, one of the purposes of the invention is to provide a preparation method of a mercury-free catalyst, which has simple steps. The second purpose of the invention is to provide a mercury-free catalyst which has the advantages of high catalytic activity, good stability, long service life and the like. The invention further aims at providing an application of the mercury-free catalyst, which has wide prospect. One of the purposes of the invention is realized by adopting the following technical scheme: a method for preparing a mercury-free catalyst, comprising the steps of: adding copper salt, active auxiliary agent and iridium complex into ethanol to obtain a mixed solution, then adopting an equal volume impregnation method to impregnate the mixed solution into pretreated active carbon, standing and drying to obtain the mercury-free catalyst; The structural formula of the active auxiliary agent is as follows: 。 Preferably, the preparation method of the active auxiliary agent comprises the following steps: Under the protection of inert gas, octamethyl silsesquioxane, N-allyl-1, 8-naphthyridine-2-formamide and a platinum catalyst are added into 1, 4-dioxane, and the active auxiliary agent is prepared after the reaction. Preferably, the dosage ratio of the octamethyl silsesquioxane to the N-allyl-1, 8-naphthyridine-2-formamide to the platinum catalyst is 1mol (4-4.1) mol (5-6) mL, the platinum catalyst is platinum (0) -1, 3-divinyl-1, 3-tetramethyl disiloxane, and the reaction temperature is 80-90 ℃ and the reaction time is 12-24h. Preferably, the preparation method of the iridium complex comprises the following steps: (1) Adding 2- (4-bromomethylphenyl) pyridine into tetrahydrofuran, and then adding hexadecyldimethyl tertiary amine, and reacting to obtain a compound 1; the structural formula of the compound 1 is as follows: (2) Adding triethylamine and acetone [ bis- (2-aminoethyl) dithioketal ] into tetrahydrofuran, and then adding a tetrahydrofuran solution of 2, 2-bipyridine-4, 4-diformyl chloride to react to prepare a compound 2; the structural formula of the compound 2 is as follows: (3) Adding the compound 1, the compound 2 and iridium trichloride hydrate into ethylene glycol diethyl ether, and carrying out reflux reaction under the protection of inert gas to obtain an iridium compound; The iridium complex has the structural formula: 。 Preferably, the molar ratio of the 2- (4-bromomethylphenyl) pyridine to the hexadecyldimethyl tertiary amine in the step (1) is 1 (2.5-3.8), the reaction time is 36-48 hours, the dosage ratio of the 2, 2-dipyridine-4, 4-diformyl chloride, acetone [ bis- (2-aminoethyl) dithioketal ] and triethylamine in the step (2) is 1mmol (2-2.5) and (8-10) mu L, and the concentration of the tetrahydrofuran solution of the 2-dipyridine-4, 4-diformyl chloride is 0.9-1mol/L. Preferably, in the step (3), the molar ratio of the compound 1 to the compound 2 to the iridium trichloride hydrate is 1 (0.56-0.64): 0.4-0.48), and the reflux reaction time is 36-48h. Preferably, the preparation method of the pretreated activated carbon comprises the following steps: and (3) soaking the activated carbon in a hydrochloric acid solution, washing and drying to obtain the pretreated activated carbon. Preferably, the copper salt is cupric chloride, the copper salt in the mercur