Beta zeolite and method for producing same
AssigneesUniZeo Co., Ltd., The University of Tokyo
InventorsKeiji Itabashi, Tatsuya Okubo, Kenta Iyoki
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Abstract
The present invention provides a beta zeolite that is useful as a catalyst, adsorbent agent, or the like, and that is both microporous and mesoporous. The beta zeolite is characterized by (i) the SiO2/Al2O3 ratio being 8-30, and the SiO2/ZnO ratio being 8-1000, (ii) the micropore surface area being 300-800 m2/g, (iii) the micropore volume being 0.1-0.3 cm3/g, and (iv) having mesopores having, in the state as synthesized, a diameter of 2-6 nm and a volume of 0.001-0.3 cm3/g. The beta zeolite is favorably produced by means of adding and reacting a zinc silicate beta zeolite as a seed crystal with a reaction mixture containing a silica source, an alumina source, an alkali source, and water.
Claims5
A beta zeolite in which:
- (i) a SiO2/Al2O3 ratio ranges from 8 to 30, and a SiO2/ZnO ratio ranges from 8 to 1000;
- (ii) a micropore surface area ranges from 300 to 800 m2/g;
- (iii) a micropore volume ranges from 0.1 to 0.3 cm3/g;
- and
- (iv) in an as-synthesized state, a diameter of a mesopore ranges from 2 to 6 nm, and a volume of the mesopore ranges from 0.001 to 0.3 cm3/g.
A method for producing a beta zeolite comprising:
- (1) mixing a silica source, an alumina source, an alkali source, and water so as to be a reaction mixture having a composition represented by a molar ratio given below;
- SiO2/Al2O3=8 to 300
- Na2O/SiO2=0.05 to 0.6
- H2O/SiO2=5 to 50
- (2) using the beta zeolite, which has a SiO2/ZnO ratio ranging from 4 to 50, a SiO2/Al2O3 ratio that is equal to or more than 4, and a mean particle size that is equal to or more than 100 nm, as a seed crystal without being fired, and adding the beta zeolite to the reaction mixture at a rate of 0.1 to 20% by weight with respect to a silica component in the reaction mixture;
- and
- (3) airtightly heating the reaction mixture to which the seed crystal is added at 80 to 200° C.
Dependencies are inferred from the claim text.