Functional structural body and method for making functional structural body
A functional structural body includes a skeletal body of a porous structure composed of a zeolite-type compound, and at least one type of metallic nanoparticles present in the skeletal body, the skeletal body having channels connecting with each other, the metallic nanoparticles being present at least in the channels of the skeletal body.
1. A functional structural body, comprising:
a skeletal body of a porous structure composed of a zeolite-type compound; and
at least one type of metallic nanoparticles present in the skeletal body,
wherein the skeletal body has channels connecting with each other, and
the metallic nanoparticles are present at least in the channels of the skeletal body,
the channels have any one of a one-dimensional pore, a two-dimensional pore, and a three-dimensional pore defined by the framework of the zeolite-type compound and an enlarged pore portion which has an inner diameter larger than any one of the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore inherent to the framework of the zeolite-type compound,
the one-dimensional pore is a tunnel-shaped or cage-shaped pore forming a one-dimensional channel; or a plurality of tunnel- shaped or cage- shaped pores forming a plurality of one-dimensional channels,
the two-dimensional pore is a two-dimensional channel in which a plurality of one-dimensional channels is connected two-dimensionally,
the three-dimensional pore is a three-dimensional channel in which a plurality of one-dimensional channels is connected three-dimensionally, and
the metallic nanoparticles are present at least in the enlarged pore portion,
wherein a particle size of the metallic nanoparticles is larger than any one of the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore of the zeolite-type compound,
wherein the zeolite-type compound is selected from the group consisting of zeolites, cation exchanged zeolites and silicalites,
wherein a framework of the zeolite-type compound is selected from the group consisting of FAU type (Y type or X type), MTW type, MFI type (ZSM-5), FER type (ferrierite), LTA type (A type), MWW type (MCM-22), MOR type (mordenite), LTL type (L type), and BEA type (beta type),
wherein the enlarged pore portion is not defined by the framework of the zeolite-type compound, and is greater than or equal to a diameter of the metallic nanoparticles.
2. The functional structural body according to claim 1 , wherein the enlarged pore portion allows a plurality of pores that constitutes any one of the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore to connect with each other.
3. The functional structural body according to claim 1 , wherein the metallic nanoparticles are a catalytic substance.
4. The functional structural body according to claim 1 , wherein an average particle size of the metallic nanoparticles is greater than an average inner diameter of the channels and is less than or equal to the inner diameter of the enlarged pore portion.
5. The functional structural body according to claim 1 , wherein a metal element (M) of the metallic nanoparticles is contained in an amount of 0.5 mass % to 2.5 mass % based on the functional structural body.
6. The functional structural body according to claim 1 , wherein an average particle size of the metallic nanoparticles is from 0.08 nm to 30 nm.
7. The functional structural body according to claim 6 , wherein the average particle size of the metallic nanoparticles is from 0.4 nm to 11.0 nm.
8. The functional structural body according to claim 1 , wherein a ratio of an average particle size of the metallic nanoparticles to an average inner diameter of the channels is from 0.05 to 300.
9. The functional structural body according to claim 8 , wherein the ratio of the average particle size of the metallic nanoparticles to the average inner diameter of the channels is from 0.1 to 30.
10. The functional structural body according to claim 9 , wherein the ratio of the average particle size of the metallic nanoparticles to the average inner diameter of the channels is from 1.4 to 3.6.
11. The functional structural body according to claim 1 , wherein an average inner diameter of the channels is from 0.1 nm to 1.5 nm, and the inner diameter of the enlarged pore portion is from 0.5 nm to 50 nm.
12. The functional structural body according to claim 1 , further comprising at least one other metallic nanoparticles held on an outer surface of the skeletal body.
13. The functional structural body according to claim 12 , wherein a content of the at least one other metallic nanoparticles present in the skeletal body is greater than a content of the at least one other metallic nanoparticles held on an outer surface of the skeletal body.
14. The functional structural body according to claim 1 , wherein the zeolite-type compound comprises a plurality of pores less than 1 nm in diameter.
15. The functional structural body according to claim 1 , wherein an inner diameter of the enlarged pore portion is from 1.1 nm to 50 nm.