Composite material of Keggin type heteropoly acid or heteropoly acid salt and carbon molecular sieve, preparation method and application thereof

Abstract

The invention provides a composite material of Keggin type heteropoly acid or heteropoly acid salt and a carbon molecular sieve, a preparation method and application thereof. In the composite material, Keggin type heteropoly acid or heteropoly acid salt molecules grow in situ in the pore channels of the carbon molecular sieve. Specifically, the structural general formula of the Keggin type heteropoly acid or heteropoly acid salt is H(Na, K)n[XM12O40], X represents a central heteroatom and X = P, Si, Ge, As, M represents a coordination atom and M=Mo, W, and n is 3 or 4; and the carbon molecularsieve is obtained by calcination of zeolite imidazole ester coordination polymer ZIF-8 under inert gas protection. The method provided by the invention utilizes the carbon molecular sieve obtained bycalcination of zeolite imidazole ester coordination polymer ZIF-8 under inert gas protection as the carrier for in-situ growth of Keggin type heteropoly acid or heteropoly acid salt molecules in thepore channels of the carbon molecular sieve, and also utilizes the pore channel size of the carbon molecular sieve to limit the loss of Keggin type heteropoly acid or heteropoly acid salt molecules inthe reaction process.

Description

technical field

[0001] The invention relates to the technical field of catalysis, in particular to a composite material of Keggin type heteropolyacid or heteropolyacid salt and carbon molecular sieve, its preparation method and application. Background technique

[0002] Heteropolyacids (HPA) are a class of oxygen-containing polyacids composed of central heteroatoms and coordination atoms through oxygen atom coordination bridges according to a certain structure, with Keggin type, Dawson type, Anderson type, Waugh type, Silverton type and Lindqvist type Type six basic structures. In addition to the six basic heteropolyacid structures, there are many other types of heteropolyacid structures due to the wide variety of elements used to prepare heteropolyacids. Among the numerous heteropolyacid structures, Keggin-type heteropolyacids have attracted more attention, not only because of the wide application of Keggin-type heteropolyacids in industrial catalysis, but also because of ...

Examples

preparation example Construction

[0033] Next, illustrate the preparation method of the composite material of Keggin type heteropolyacid or heteropolyacid salt and carbon molecular sieve according to the second aspect of the present invention, for preparing the Keggin type heteropolyacid or heteropolyacid salt described in the first aspect of the present invention And the composite material of carbon molecular sieve, comprises steps:

[0034] (1) Under the protection of an inert gas, the zeolite imidazole ester coordination polymer ZIF-8 is calcined to obtain a carbon molecular sieve; (2) at normal temperature and pressure, the coordination atom salt solution is dispersed into the carbon molecular sieve in equal volume, and then Under the condition of heating and stirring, an excessive amount of central heteroatom salt is added, wherein the equal volume dispersion refers to the volume of the total volume of the coordination atom salt solution and the volume of the solvent that can be adsorbed by the carbon mole...

Embodiment 1

[0047] Under the protection of nitrogen, calcinate ZIF-8 at 920°C for 4 hours, then lower the temperature, collect black powder to obtain carbon molecular sieve, and the BET specific surface area of ​​carbon molecular sieve is 1580m 2 / g, the pore size is 1.20nm, the N element content is 1.2%, and the iodine value is 800mg / g.

[0048] At normal temperature and pressure, will contain 0.22g Na 2 WO 3 2H 2 O 0.8ml aqueous solution is dispersed into 0.4g carbon molecular sieve, then the temperature is raised to 65°C, and 0.24g NaH is added 2 PO 4 12H 2 O, continue to react for 30 minutes, then raise the temperature to 95°C, slowly add 0.13ml of concentrated hydrochloric acid dropwise, the reaction is over for 30 minutes, collect the solid by centrifugation, wash the solid with hydrochloric acid of pH = 1-2 for 2-3 times, and then wash with water 2 to 3 times, Keggin-H can be obtained after drying 3 PW 12 o 40 @CMS Composites.

[0049] figure 1 The prepared Keggin-H 3 PW...

Embodiment 2

[0056] Under the protection of nitrogen, calcinate ZIF-8 at 920°C for 4 hours, then lower the temperature, collect black powder to obtain carbon molecular sieve, and the BET specific surface area of ​​carbon molecular sieve is 1580m 2 / g, the pore size is 1.20nm, the N element content is 1.2%, and the iodine value is 800mg / g.

[0057] At normal temperature and pressure, will contain 0.364g Na 2 WO 3 2H 2 0.8ml aqueous solution of O was dispersed into 0.4g carbon molecular sieve, then heated to 65℃, and 0.25g Na 2 SiO 3 ·5H 2 O, continue to react for 30 minutes, then raise the temperature to 95°C, slowly add 0.2ml of concentrated hydrochloric acid dropwise, the reaction is over for 30 minutes, collect the solid by centrifugation, wash the solid with hydrochloric acid of pH = 1-2 for 2-3 times, and then wash with water 2 to 3 times, Keggin-H can be obtained after drying 4 SiW 12 o 40 @CMS Composites.

[0058] Keggin-H 4 SiW 12 o 40 The morphology of the @CMS composit...

technical field

[0001] The invention relates to the technical field of catalysis, in particular to a composite material of Keggin type heteropolyacid or heteropolyacid salt and carbon molecular sieve, its preparation method and application. Background technique

[0002] Heteropolyacids (HPA) are a class of oxygen-containing polyacids composed of central heteroatoms and coordination atoms through oxygen atom coordination bridges according to a certain structure, with Keggin type, Dawson type, Anderson type, Waugh type, Silverton type and Lindqvist type Type six basic structures. In addition to the six basic heteropolyacid structures, there are many other types of heteropolyacid structures due to the wide variety of elements used to prepare heteropolyacids. Among the numerous heteropolyacid structures, Keggin-type heteropolyacids have attracted more attention, not only because of the wide application of Keggin-type heteropolyacids in industrial catalysis, but also because of ...

Examples

preparation example Construction

[0033] Next, illustrate the preparation method of the composite material of Keggin type heteropolyacid or heteropolyacid salt and carbon molecular sieve according to the second aspect of the present invention, for preparing the Keggin type heteropolyacid or heteropolyacid salt described in the first aspect of the present invention And the composite material of carbon molecular sieve, comprises steps:

[0034] (1) Under the protection of an inert gas, the zeolite imidazole ester coordination polymer ZIF-8 is calcined to obtain a carbon molecular sieve; (2) at normal temperature and pressure, the coordination atom salt solution is dispersed into the carbon molecular sieve in equal volume, and then Under the condition of heating and stirring, an excessive amount of central heteroatom salt is added, wherein the equal volume dispersion refers to the volume of the total volume of the coordination atom salt solution and the volume of the solvent that can be adsorbed by the carbon mole...

Embodiment 1

[0047] Under the protection of nitrogen, calcinate ZIF-8 at 920°C for 4 hours, then lower the temperature, collect black powder to obtain carbon molecular sieve, and the BET specific surface area of ​​carbon molecular sieve is 1580m 2 / g, the pore size is 1.20nm, the N element content is 1.2%, and the iodine value is 800mg / g.

[0048] At normal temperature and pressure, will contain 0.22g Na 2 WO 3 2H 2 O 0.8ml aqueous solution is dispersed into 0.4g carbon molecular sieve, then the temperature is raised to 65°C, and 0.24g NaH is added 2 PO 4 12H 2 O, continue to react for 30 minutes, then raise the temperature to 95°C, slowly add 0.13ml of concentrated hydrochloric acid dropwise, the reaction is over for 30 minutes, collect the solid by centrifugation, wash the solid with hydrochloric acid of pH = 1-2 for 2-3 times, and then wash with water 2 to 3 times, Keggin-H can be obtained after drying 3 PW 12 o 40 @CMS Composites.

[0049] figure 1 The prepared Keggin-H 3 PW...

Embodiment 2

[0056] Under the protection of nitrogen, calcinate ZIF-8 at 920°C for 4 hours, then lower the temperature, collect black powder to obtain carbon molecular sieve, and the BET specific surface area of ​​carbon molecular sieve is 1580m 2 / g, the pore size is 1.20nm, the N element content is 1.2%, and the iodine value is 800mg / g.

[0057] At normal temperature and pressure, will contain 0.364g Na 2 WO 3 2H 2 0.8ml aqueous solution of O was dispersed into 0.4g carbon molecular sieve, then heated to 65℃, and 0.25g Na 2 SiO 3 ·5H 2 O, continue to react for 30 minutes, then raise the temperature to 95°C, slowly add 0.2ml of concentrated hydrochloric acid dropwise, the reaction is over for 30 minutes, collect the solid by centrifugation, wash the solid with hydrochloric acid of pH = 1-2 for 2-3 times, and then wash with water 2 to 3 times, Keggin-H can be obtained after drying 4 SiW 12 o 40 @CMS Composites.

[0058] Keggin-H 4 SiW 12 o 40 The morphology of the @CMS composit...

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