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CN-119954174-B - Metal modified hydrogen ZSM-5 molecular sieve, synthesis method thereof and 1-hexene hydroformylation catalyst

CN119954174BCN 119954174 BCN119954174 BCN 119954174BCN-119954174-B

Abstract

The invention provides a metal modified hydrogen ZSM-5 molecular sieve, a synthesis method thereof and a 1-hexene hydroformylation catalyst. The synthesis method comprises the steps of dissolving an organic amine ligand and metal salt in deionized water, stirring to obtain a solution A, dissolving a sodium-free silicon source and an aluminum source in the deionized water, stirring to obtain a solution B, mixing the solution B with the solution A, adding a template agent and ammonia water to obtain a reaction solution, and performing hydrothermal crystallization, cooling, centrifugation, drying and roasting to obtain the metal modified hydrogen ZSM-5 molecular sieve. The invention adopts ammonia water as mineralizer, and directly introduces metal into hydrogen-type HZSM-5 molecular sieve in situ by one-step method, thereby omitting the steps of repeated ion exchange and roasting in the traditional method and reducing the wastewater discharge and pollution. The metal in the metal modified hydrogen ZSM-5 molecular sieve is uniformly dispersed, can be applied to a 1-hexene hydroformylation catalyst, and has higher 1-hexene conversion rate and n-heptanal selectivity.

Inventors

  • ZHANG ZHONGDONG
  • LI YANPING
  • FENG RUI
  • ZHANG ZHAOQIAN
  • TONG NA
  • WANG JIAN
  • FANG ZHOU
  • LIU ZONGQIANG
  • ZHANG TAO
  • WANG RUIPU

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260505
Application Date
20231109

Claims (20)

  1. 1. A synthesis method of a metal modified hydrogen ZSM-5 molecular sieve, wherein the synthesis method comprises the following steps: s1, dissolving an organic amine ligand and metal salt in deionized water to obtain a solution A; S2, dissolving a sodium-free silicon source and a sodium-free aluminum source in deionized water to obtain a solution B; S3, adding the solution B into the solution A, stirring 5-20 min, adding a template agent, stirring 0.5-3 h, finally adding ammonia water, stirring 12-24 and h, uniformly mixing to obtain a reaction solution, and performing hydrothermal crystallization, cooling, centrifugation, drying and roasting to obtain the metal modified hydrogen ZSM-5 molecular sieve; In the step S3, the chemical composition of the reaction solution meets the following mole ratio range of SiO 2 /Al 2 O 3 = 50-200, ammonia /SiO 2 ＝2-10,TPA + /SiO 2 ＝0.05-0.35,H 2 O/SiO 2 ＝40-80,M/SiO 2 = 0.001-0.05, organic amine ligand/M = 5-20, wherein TPA + is the mole number of cations in the template agent, M is the mole number of metal ions in the metal salt, and ammonia is calculated by ammonium ions; The sodium-free silicon source is silica sol.
  2. 2. The synthesis method according to claim 1, wherein in step S3, the aqueous ammonia is added under stirring for a period of 12 to 18 h.
  3. 3. The synthesis method according to claim 1, wherein the solution B and the solution a are mixed by stirring for a period of 10 to 15 min.
  4. 4. The method of claim 1, wherein the templating agent is added with stirring for a period of time ranging from 1 to 2 h.
  5. 5. The synthesis method according to claim 2, wherein in step S3, the stirring speed at the time of adding the aqueous ammonia is 500 to 2000 rpm.
  6. 6. A synthetic method according to claim 3, wherein the stirring speed of the solution B when mixed with the solution a is 800-1500 rpm.
  7. 7. The synthesis method according to claim 4, wherein the stirring speed when the template is added is 950-1100 rpm.
  8. 8. The synthesis method according to claim 1, wherein in step S1, the metal in the metal salt is one or a combination of two or more of Fe, co, cu, zn, rh, pd and Pt.
  9. 9. The synthesis method according to claim 1, wherein in step S1, the organic amine ligand is ethylenediamine and/or 3-aminopropyl triethoxysilane.
  10. 10. The synthesis method according to claim 1, wherein in step S2, the sodium-free silicon source is a silica sol having a particle size of 5 to 50 nm.
  11. 11. The synthesis method according to claim 1, wherein in step S2, the sodium-free aluminum source comprises one or a combination of two or more of pseudo-boehmite, aluminum nitrate, aluminum chloride and aluminum sulfate.
  12. 12. The synthesis method according to claim 1, wherein in step S3, the template agent is tetrapropylammonium hydroxide and/or tetrapropylammonium bromide.
  13. 13. The synthesis method according to claim 1, wherein in step S3, the drying temperature is 60-150 ℃.
  14. 14. The synthesis method according to claim 13, wherein in step S3, the drying temperature is 60-80 ℃.
  15. 15. The synthesis method according to claim 1, wherein in step S3, the drying time is 8-24 h.
  16. 16. The synthesis method according to claim 1, wherein in step S3, the temperature of the hydrothermal crystallization is 140-180 ℃.
  17. 17. The synthesis method according to claim 1, wherein in step S3, the hydrothermal crystallization time is 12-96 h.
  18. 18. The synthesis method according to claim 1, wherein in step S3, the firing temperature is 350-500 ℃.
  19. 19. The synthesis method according to claim 1, wherein in step S3, the roasting time is 3-8 h.
  20. 20. A metal modified hydrogen form ZSM-5 molecular sieve obtained by the synthesis process of any of claims 1-19.

Description

Metal modified hydrogen ZSM-5 molecular sieve, synthesis method thereof and 1-hexene hydroformylation catalyst Technical Field The invention relates to the field of catalytic materials, in particular to a synthesis method of a metal modified hydrogen ZSM-5 molecular sieve and a 1-hexene hydroformylation reaction catalyst. Background The ZSM-5 molecular sieve has adjustable acidity, good thermal stability and hydrothermal stability, the special pore structure determines the shape-selective advantage of the ZSM-5 molecular sieve in catalysis, and the ZSM-5 molecular sieve is widely applied to various chemical fields such as preparation of toluene and dimethylbenzene by catalytic pyrolysis and alkylation, isomerization, preparation of olefin by methanol and the like. In order to improve the catalytic activity, selectivity and stability of ZSM-5 molecular sieve in different reaction processes, it is necessary to modify it by proper metal modification. For example, the addition of Fe improves the selectivity of light olefins and propylene in the naphtha catalytic cracking reaction and the stability of ZSM-5, and the introduction of Zn improves the aromatic hydrocarbon yield of aromatic hydrocarbon prepared by methanol reaction, and researches show that Zn-ZSM-5 is the most effective catalyst for improving the selectivity of monocyclic aromatic hydrocarbon comprising BTX (benzene, toluene and xylene). The introduction of a small amount of Cu can keep the balance between the dehydrogenation activity of the metal and the shape selectivity of ZSM-5, and is beneficial to improving the yield of light olefins in the FCC process. Wang (J Mater Sci 56,18050-18060 (2021)) reports a method for green synthesis of Fe-ZSM-5 molecular sieves by a one-pot method, which comprises the steps of uniformly mixing ferric nitrate with sodium aluminate, sodium hydroxide and alkaline silica sol without adding a seed template agent, drying at 100 ℃ to prepare xerogel, crystallizing at 170 ℃ by a Steam Assisted Crystallization (SAC), and finally cooling, filtering, washing and drying to prepare Na-type Fe-ZSM-5 zeolite. CN104525246B discloses a method for preparing small crystal grain Zn-ZSM-5 catalyst without template agent and its application. The method is to directly add zinc salt in the preparation process of the molecular sieve, and obtain the sodium Zn-ZSM-5 molecular sieve catalyst through hydrothermal crystallization, filtration, drying and roasting. And then carrying out ion exchange on the Zn-ZSM-5 molecular sieve catalyst in an ammonium salt solution to obtain the hydrogen type small-grain Zn-ZSM-5 catalyst required by the reaction of preparing gasoline from methanol. The catalyst preparation process does not need to add a template agent, the obtained Zn-ZSM-5 has uniform particle size and regular morphology, but the process needs multiple times of ion exchange. CN114950351a discloses a method for modifying ZSM-5 molecular sieve, which is to dope metal cations (Cu 2+、La2+、Ce3+, etc.) into the framework structure of ZSM-5 molecular sieve, improving the performance of adsorbing VOCs. The specific experimental steps are that ZSM-5 molecular sieve is taken, the prepared metal salt solution is added, and the mixture is moved into a hydrothermal reaction kettle, and the temperature is raised to 80-150 ℃ for 4-10h. Naturally cooling to normal temperature, filtering, drying and calcining to obtain the metal cation doped modified molecular sieve. The synthesis conditions are mild and easy to control, the molecular sieve synthesized by the method is sodium type, and the hydrogen type molecular sieve can be obtained by multiple ion exchange and roasting, so that the process is complicated. CN114426290A discloses a sodium-free Fe-ZSM-5 molecular sieve synthesis method, which comprises the steps of firstly carrying out hydrothermal treatment on Silicate-1 seed crystal under alkaline condition, then adding the seed crystal into a molecular sieve synthesis raw material liquid, and carrying out hydrothermal treatment to obtain the sodium-free Fe-ZSM-5 molecular sieve, wherein ion exchange is not required in the synthesis process, the b-axis size of the synthesized molecular sieve is 5-50nm, the size is small, the mass transfer of reaction molecules is facilitated, and the reactivity of reducing ammonia gas to remove atmospheric pollution NO x is effectively improved. But the synthesis process requires the addition of seed crystals and size inhibitors (NH 2-C6H4-CH2-C6H4-NH2) and requires two hydrothermal processes. At present, the metal modified hydrogen type ZSM-5 molecular sieve catalyst prepared by the conventional method mostly adopts a post-impregnation method, the process is complicated, and when a metal source is directly added into an alkaline system synthesized by the ZSM-5 molecular sieve, the metal precipitation rate is far faster than the crystallization rate of the molecular sieve, so that the effective dispersion of the metal in