MFI zeolite having uniform mesopores and method for producing same

Patent metadata

Field	Value
Publication number	US-9789476-B2
Application number	US-201314380795-A
Country	US
Kind code	B2
Filing date	Mar 25, 2013
Priority date	Mar 26, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A novel MFI zeolite that when used as a catalyst, can be used for a selective catalytic reaction for larger molecules and provides a method for producing the MFI zeolite. The MFI zeolite includes uniform mesopores having a pore distribution curve which a peak-width thereof at half height (hw) is at most 20 nm (hw≦20 nm) and a center value (μ) of a maximum peak is 10 nm or more and 20 nm or less (10 nm≦μ≦20 nm), and having a pore volume (pv) of the uniform mesopores of at least 0.05 mL/g (0.05 mL/g≦pv); the MFI zeolite has no peak in a range of 0.1° to 3° in powder X-ray diffraction measurement with a diffraction angle represented by 2θ; and the MFI zeolite has an average particle diameter (PD) of at most 100 nm (PD≦100 nm).

First claim

The invention claimed is:

1. An MFI zeolite comprising the following properties:
(i) the MFI zeolite includes uniform mesopores having a pore distribution curve which a peak-width thereof at half height (hw) is at most 20 nm (hw≦20 nm) and a center value (μ) of a maximum peak is 10 nm or more and 20 nm or less (10 nm≦μ≦20 nm), and having a pore volume (pv) of the uniform mesopores of at least 0.05 mL/g (0.05 mL/g≦pv);
(ii) the MFI zeolite has no peak in a range of 0.1° to 3° in powder X-ray diffraction measurement with a diffraction angle represented by 2θ; and
(iii) the MFI zeolite has an average particle diameter (PD) of at most 100 nm (PD≦100 nm),
wherein an SiO 2 /Al 2 O 3 molar ratio is 39 or more and 200 or less (39≦SiO 2 /Al 2 O 3 molar ratio≦200).

2. The MFI zeolite according to claim 1 , wherein the peak-width at half height (hw) is 10 nm or less (hw≦10 nm).

3. The MFI zeolite according to claim 1 , wherein a ratio (pvr) of the pore volume of the uniform mesopores having the properties shown in (i) with respect to a total pore volume of mesopores is 30% or more and 100% or less (30%≦pvr≦100%).

4. A method for producing the MFI zeolite according to claim 1 , the method comprising subjecting a raw material composition having the following chemical composition to hydrothermal synthesis:
0.03≦tetrapropylammonium cation/Si molar ratio;
OH/Si molar ratio≦0.22;
20≦SiO 2 /Al 2 O 3 molar ratio≦300; and
5≦H 2 O/Si molar ratio≦20.

5. The MFI zeolite according to claim 1 , wherein a ratio (pvr) of the pore volume of the uniform mesopores having the properties shown in (i) with respect to a total pore volume of mesopores is 30% or more and 100% or less (30%≦pvr≦100%).

Assignees

• Tosoh Corp

Inventors

• Takamitsu Yasuyuki
• Yoshida Satoshi

Classifications

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title