Process for the microwave induced preparation of crystalline microporous titanium silicalite

• US 6,387,349 B1
• Filed: 03/26/2001
• Issued: 05/14/2002
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: Council of Scientific & Industrial Research
• Original Assignee: Council of Scientific & Industrial Research
• Inventors: Kamalakar, Gunda, Rao, Katabathini Narsimha, Prasad, Muppa Ramakrishna, Raghavan, Kondapuram Vijaya, Kulkarni, Shivanand Janardan, Prasad, Potharaju Seetharamanjaneya Sai
• Primary Examiner(s): SAMPLE, DAVID R
• Application Number:
  US09/817,745
• Time in Patent Office: 414 Days
• Field of Search: 423/705, 423/707, 423/713, 423/326, 423/DIG.22
• US Class Current: 423/707
• CPC Class Codes: B01J 29/405 containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead
• CPC Class Codes: B01J 29/89 Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium B01J29/005 takes precedence
• CPC Class Codes: B01J 37/346 of microwave energy
• CPC Class Codes: C01B 37/005 Silicates, i.e. so-called metallosilicalites or metallozeosilites
• CPC Class Codes: Y10S 423/22 MFI, e.g. ZSM-5. silicalite, LZ-241

Abstract

The present invention relates to a process for the microwave induced preparation of crystalline, microporous titanium silicalite. More particularly; the present invention relates to a process for the preparation of crystalline microporous titanium silicalite of the formula: xTiO₂:(1−x)SiO₂ wherein x is greater than 0.043 and less than or equal to 0.11. These silicalites, prepared under microwave irradiation have the same physico-chemical properties as titanium silicalite prepared by hydrothermal methods.

Claims

1. A process for the microwave induced preparation of a crystalline, microporous titanium silicalite having the chemical formula:

xTiO₂·

(1−

x)SiO₂, wherein x is greater than or equal to 0.043 and less than or equal to 0.11, an x-ray diffraction pattern as follows;

2. A process as claimed in claim 1 wherein x is at least 0.050.

3. A process as claimed in claim 1 wherein said gel further comprises an alcohol of the formula R-OH where R is an alkyl group having 2-5 carbon atoms.

4. A process as claimed in claim 3 wherein the said alcohol is selected from the group consisting of ethyl, propyl, isopropyl, butyl, isobutyl and mixtures thereof.

5. A process as claimed in claim 1, wherein the source of titanium oxide is a titanium alkoxide.

6. A process as claimed in claim 1 wherein the source of said silicon oxide is selected from the group consisting of alkoxides, amorphous silica and colloidal silica.

7. A process as claimed in claim 1 wherein the source of said silicon oxide is tetraalkyl orthosilicate.

8. A process as claimed in claim 1, wherein said gel has a molar composition of 0.043-0.11 TiO₂:

1SiO₂;

0.3-0.8(C₃H₇)₄N⁺;

2.0-5.0ROH;

10-100 H₂O, wherein R is alkyl group having less than or equal to 5 carbon atoms.

9. A process as claimed in claim 1 wherein the said gel is kept in a microwave oven and then irradiated.

10. A process as claimed in claim 9 wherein the said gel is irradiated in a microwave oven by exposing the gel to radiation with an applied power in the range 500 to 1000W.