Metallosilicates, processes for producing the same, nitrogen oxide removal catalyst, process for producing the same, and method for removing nitrogen oxide with the same

Patent metadata

Field	Value
Publication number	US-9675935-B2
Application number	US-201013503450-A
Country	US
Kind code	B2
Filing date	Dec 21, 2010
Priority date	Dec 22, 2009
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

The invention relates to: a β-type iron silicate which has a fluorine content not more than 400 ppm by weight on a dry basis and in which the crystal grains have a truncated square bipyramidal morphology in an examination with a scanning electron microscope and the whole or part of the iron is contained in the β-type framework structure, and a process for producing the iron silicate; anther β-type iron silicate, and a process for producing the iron silicate; and a nitrogen oxide removal catalyst containing the other β-type iron silicate, a process for producing the catalyst, and a method for nitrogen oxide removal with the catalyst.

First claim

The invention claimed is:

1. A β-type framework structure iron silicate comprising primary particles obtained from growth of crystal, characterized in that the iron silicate has a fluorine content not more than 400 ppm by weight of the dry crystals, that the primary particles of the crystals have a truncated square bipyramidal morphology in an examination with a scanning electron microscope, and that the whole or part of the iron is contained in the β-type framework structure.

2. The β-type iron silicate according to claim 1 which is characterized by having an SiO 2 /Al 2 O 3 (molar ratio) of 300 or more and containing iron in an amount of 5.5% by weight or more based on the dry weight of the crystals.

3. A process for producing the n-type iron silicate according to claim 1 , characterized by hydrothermally crystallizing the following starting-material composition
a M 2 O.SiO 2 .b Fe 2 O 3 .c Al 2 O 3 .d SDA. e H 2 O
(M represents Na + or K + , SDA represents a structure-directing agent, and a, b, c, d, and e respectively indicate the molar ratios of the M 2 O, Fe 2 O 3 , Al 2 O 3 , SDA, and H 2 O to the SiO 2 ),
wherein the (SDA/SiO 2 ) molar ratio (d) is 0.10-0.35 and (e) is 7 to 15.

4. The process for producing a β-type iron silicate according to claim 3 which is characterized in that the starting-material composition satisfies the following:
a=0.075 to 0.50
b=0.01 to 0.05
and c=0.01 or less.

Assignees

• Naraki Yusuke
• Tokunaga Keisuke
• Ariga Ko
• Tosoh Corp

Inventors

• Naraki Yusuke
• Tokunaga Keisuke
• Ariga Ko

Classifications

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• C01B39/087

  Ferrosilicates · CPC title

• B01J29/7615

  Zeolite Beta · CPC title

• C01B39/48 Primary

  using at least one organic template directing agent · CPC title

• B01D2255/20738

  Iron · CPC title