Titanium silicalite molecular sieve and its synthesis

Patent metadata

Field	Value
Publication number	US-9896343-B2
Application number	US-201414527657-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Oct 29, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The present invention relates to a titanium silicalite molecular sieve, wherein the crystal grain of the titanium silicalite molecular sieve has a ratio of (surface Si/Ti ratio):(bulk Si/Ti ratio) being larger than 1.1 and less than 5.

First claim

We claim:

1. A titanium silicalite molecular sieve, wherein a crystal grain of the titanium silicalite molecular sieve has a ratio of (surface Si/Ti ratio):(bulk Si/Ti ratio) being larger than 1.1 and less than 5,
wherein the titanium silicalite molecular sieve has a micropore structure with a pore diameter less than 1 nm and a mesopore structure with a pore diameter of 2-8 nm, a volume of pores having a pore diameter of 2-8 nm is 0.3-0.8 mL/g, a volume of pores having a pore diameter being less than 1 nm is 0.12-0.19 mL/g.

2. A titanium silicalite molecular sieve, wherein a crystal grain of the titanium silicalite molecular sieve has a ratio of (surface Si/Ti ratio):(bulk Si/Ti ratio) larger than 1.1 and less than 5,
wherein the crystal grain of the titanium silicalite molecular sieve has a hollow structure and a diameter of a hollow portion of the hollow crystal grain is 5-300 nm.

3. The titanium silicalite molecular sieve of claim 2 , wherein the titanium silicalite molecular sieve is a TS-1 molecular sieve, a TS-2 molecular sieve, or a Ti-β molecular sieve.

4. The titanium silicalite molecular sieve of claim 2 , wherein the ratio of (surface Si/Ti ratio):(bulk Si/Ti ratio) is (1.2-4):1.

5. The titanium silicalite molecular sieve of claim 2 , wherein the titanium silicalite molecular sieve has a Ti/Si molar ratio of (0.005-0.03):1.

6. The titanium silicalite molecular sieve of claim 2 , wherein the titanium silicalite molecular sieve has a Ti/Si molar ratio of (0.01-0.025):1.

7. The titanium silicalite molecular sieve of claim 2 , having an adsorption capacity of benzene measured under the conditions of 25° C., P/P0=0.10, and 1 hour of adsorption time of at least 70 mg/g.

8. The titanium silicalite molecular sieve of claim 2 , wherein the Si/Ti ratio by atom decreases in a direction from the surface to the interior of the titanium silicalite molecular sieve.

9. A process for synthesizing a titanium silicalite molecular sieve of claim 2 , comprising the following steps of:
(1) a titanium source, a template agent, an organic silicon source, water and an optional inorganic amine source are mixed and subjected to hydrolyzation and removing alcohols;
(2) the product obtained in the step (1) is aged at 15-50° C.;
(3) the aged product obtained in the step (2) and a solid silicon source are mixed homogeneously, then subjected to crystallization in a close reaction vessel, and the titanium silicalite molecular sieve is collected.

10. The process of claim 9 , wherein the titanium source is an organic titanium source and/or an inorganic titanium source;
the template agent is one or more of an organic quaternary ammonium base, an organic amine, an organic quaternary ammonium salt, and an long-chain alkyl ammonium compound, wherein the molar ratio of the organic quaternary ammonium base to the total silicon source is zero or (0.05-0.36):1; the molar ratio of the organic amine to the total silicon source is (0-0.45):1; the molar ratio of the organic quaternary ammonium salt to the total silicon source is (0-0.45):1; and the molar ratio of the long-chain alkyl ammonium compound to the total silicon source is zero or (0.04-0.45):1;
the organic silicon source is an organic silicate, which has a general formula of Si(OR 1 ) 4 , R 1 is a linear or branched C 1 -C 6 alkyl;
the solid silicon source is a high purity silica particle or powder, on a dry basis and by weight, the solid silicon source has a SiO 2 content of more than 99.99 wt %, and a total content by atom of Fe, Al and Na of less than 10 ppm;
the inorganic amine source is an inorganic ammonium salt and/or aqueous ammonia.

11. The process of claim 9 , wherein
the molar ratio of the titanium source (as TiO2) to the total silicon source (as SiO 2 ) is (0.005-0.05):1;
the molar ratio of the template agent to the total silicon source (as SiO 2 ) is (0.05-0.6):1;
the molar ratio of water to the total silicon source (as SiO 2 ) is (5-100):1;
the molar ratio of the inorganic amine source (as NH 4 + ) to the titanium source (as TiO2) is (0-5):1; and
the weight ratio of the aged product (as SiO 2 ):the solid silicon source (as SiO 2 ) is 1:(0.1-10).

12. The process of claim 9 , wherein the aging in the step (2) is conducted by keeping the product by standing at 15-50° C. for 1-60 hours.

13. The process of claim 9 , wherein in the step (3), the crystallization temperature is 110° C. to 200° C.;
the crystallization pressure is an autogenous pressure; the crystallization time is 2 hours to 20 days.

14. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium base and/or an organic amine, and optionally an organic quaternary ammonium salt.

15. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium base and/or an organic amine, and optionally an organic quaternary ammonium salt, wherein the molar ratio of the organic quaternary ammonium base to the organic amine is 1:(0-10), and the molar ratio of the organic quaternary ammonium base to the organic quaternary ammonium salt is 1:(0-10).

16. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium salt and an organic base.

17. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium salt and an organic base, wherein the molar ratio of the organic quaternary ammonium salt to the total silicon source is (0.04-0.55):1, the molar ratio of the organic quaternary ammonium base to the organic quaternary ammonium salt is (0.04-0.45):1, and the molar ratio of the inorganic amine source (as NR 4 + ) to the titanium source (as TiO2) is (0-0.5):1.

18. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium base and/or an organic quaternary ammonium salt, an optional organic amine, and a long-chain alkyl ammonium compound.

19. The process of claim 9 , wherein in the step (1), the template agent comprises an organic quaternary ammonium base and/or an organic quaternary ammonium salt, an optional organic amine, and a long-chain alkyl ammonium compound, wherein the molar ratio of (the organic quaternary ammonium base and the organic quaternary ammonium salt) to the total silicon source is (0.04-0.45):1, and the molar ratio of the long-chain alkyl ammonium compound and the total silicon source is (0.04-0.45):1.

20. The process of claim 9 , wherein the template agent is selected from the group consisting of:
(1) an organic quaternary ammonium base and optionally a long-chain alkyl ammonium compound;
(2) an organic quaternary ammonium salt, an organic amine and optionally a long-chain alkyl ammonium compound;
(3) an organic quaternary ammonium salt and a long-chain alkyl ammonium compound.

21. The process of claim 9 , wherein
the titanium silicalite molecular sieve is a TS-1 molecular sieve, wherein the template agent is one or more of tetrapropylammonium hydroxide, tetrapropylammonium chloride and tetrapropylammonium bromide, and optionally an organic amine and/or a long-chain alkyl ammonium compound; or,
the titanium silicalite molecular sieve is a TS-2 molecular sieve, wherein the template agent is one or more of tetrabutylammonium hydroxide, tetrabutylammonium chloride and tetrabutylammonium bromide, and optionally an organic amine and/or a long-chain alkyl ammonium compound; or,
the titanium silicalite molecular sieve is a Ti-β molecular sieve,

Assignees

• China Petroleum & Chem Corp
• Sinopec Res Inst Petroleum

Inventors

• Xia Changjiu
• Zhu Bin
• Lin Min
• Peng Xinxin
• Shu Xingtian
• Shi Chunfeng

Classifications

• C01P2006/17

  Pore diameter distribution · CPC title

• C01B39/085

  Group IVB- metallosilicates · CPC title

• C01B39/00 Primary

  Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination (treatment to modify the sorption properties, e.g. shaping using a binder, B01J20/10; treatment to modify the catalytic properties, e.g. combination of treatments to make the zeolites appropriate to their use as a catalyst, B01J29/04; treatment to improve the ion-exchange properties B01J39/14) · CPC title

• C01P2004/90

  Other morphology not specified above · CPC title