CN1299986C - Organic and inorganic carbon hybridized silicon zeolite solid acid cellular material and its prepn - Google Patents

Abstract

The present invention relates to novel full silicon organic and inorganic carbon hybridization zeolite solid acid and a preparation method thereof, which belongs to the technical field of a microporous material. The material is obtained in a mode that a full silicon zeolite molecular sieve is mixed with an aldehyde solution or solid to carry out hydrothermal reaction or gas/solid phase reaction, and an aldehyde group partially replaces framework oxygen. The solid acidity of a novel catalyzing material and the property of a pore canal can be regulated and controlled by changing the length of an alkyl group carbon chain of the C1-C3 of aldehyde and the structure of base zeolite, and therefore, the requirement for the acidity of the material, a pore structure and surface property in practical application is satisfied. The material has the advantages of mild synthetic condition, good repetitiveness, simple and convenient preparation, low price and no environmental pollution, and is suitable for industrialized production.

Description

A kind of all-silicon organic inorganic carbon hybrid zeolite solid acid microporous material and preparation method thereof

technical field

The invention belongs to the technical field of microporous materials, and in particular relates to a novel all-silicon organic-inorganic hybrid zeolite solid acid and a preparation method thereof. The material has wide application prospects in catalysis, adsorption and alkaline separation.

Background technique

Traditional solid acids include many kinds, such as naturally occurring clay minerals and zeolites, metal oxides such as silica and alumina, and inorganic substances such as sulfides, sulfates, and nitrates. As acid catalysts, they all have different acid sites and different selectivities. The acidic centers of alumina are incompletely coordinated aluminum atoms formed by dehydration, and there are two acidic maxima at around 773K and 993K; the acidic centers of zeolites are mainly Brnsted acid sites and Lewis acid sites of the framework, of which Different cations and different silicon-aluminum ratios lead to different acid strengths. Usually, the solid acidity of zeolite can be tuned by introducing other central atoms or alkaline earth metal cations. However, on the one hand, the introduction of inorganic atoms can easily cause the pollution of the catalytic system, and on the other hand, the inorganic ions are easily lost in aqueous solution, which will lead to the instability of the acidity of the zeolite.

In recent years, organic-inorganic hybrid ordered mesoporous materials (PMOs) have attracted increasing attention due to their wide applications in catalysis, ion exchange, semiconductors, chemical sensing, and nanomolecular sieves. The introduction of organic groups can change many properties of materials, such as adsorption and separation properties, surface properties, and even electrochemical and mechanical properties.

Shiyou Guan et al. reported (J.Am.Chem.Soc.2000, 122, 5660-5661) to use BTME((CH ₃ O) ₃ Si-CH ₂ -CH ₂ -Si(OCH ₃ ) ₃ )-ATME(C The system of _n H _2n+1 N ⁺ (CH ₃ ) ₃ )-NaOH-H ₂ O synthesized organic-inorganic hybrid mesoporous molecular sieves containing (Si-CH ₂ -CH ₂ -Si) structure in situ at 368K. However, no special properties have been reported in terms of acid properties.

Different from traditional solid acidic zeolites and organic-inorganic hybrid ordered mesoporous materials, the all-silicon organic-inorganic hybrid zeolite solid acid not only has adjustable and stable solid acidity and good pore structure, but also because of its acid center and The above two are different, pollution and loss will not occur. As a catalyst, it has the advantages of high activity, high selectivity, mild reaction conditions, and easy separation of products, and is expected to become a new generation of environmentally friendly catalytic materials. It has strong application prospects in adsorption and separation of basic organic molecules.

Contents of the invention

The purpose of the present invention is to propose a novel all-silicon organic-inorganic hybrid zeolite solid acid with good catalytic performance and low manufacturing cost and a preparation method thereof.

The all-silicon organic-inorganic hybrid zeolite solid acid proposed by the present invention is obtained by replacing 1-20% of the skeleton oxygen in the oxygen-containing all-silicon microporous material with an aldehyde organic functional group, wherein the aldehyde group is RCHO, and R here is C ₀ -C ₂ hydrocarbons, such as formaldehyde, propionaldehyde, etc.

In the above-mentioned all-silicon organic-inorganic hybrid zeolite solid acid, the oxygen-containing all-silicon microporous material in the skeleton refers to a crystalline aluminum-free all-silicon zeolite molecular sieve.

The preparation method of the above-mentioned all-silicon organic-inorganic hybrid zeolite solid acid microporous material is as follows:

Mix the all-silicon microporous substrate material with oxygen-containing skeleton and the solid or solution of organic carbon hybridization agent-aldehydes, and place it in a reaction kettle for hydrothermal reaction at a temperature of 20-200°C for 1.5-50 hours to obtain a full-body Silica zeolite solid acid microporous material.

The solid or solution of the aldehyde hybridization agent is placed in the bottom layer of the reactor, the base material is placed in the upper layer, and the steam generated during heating is used for gas/solid phase reaction with the base material to prepare the all-silica zeolite solid acid microporous material.

In the above method, the oxygen-containing all-silicon microporous substrate material of the skeleton can adopt commercial all-silica zeolite molecular sieves, such as: all-silicon MF1 zeolite, all-silicon FER zeolite and other substrate materials are hydrothermally reacted with an aldehyde organic carbon hybrid agent or A gas/solid phase reaction occurs to prepare an all-silicon organic-inorganic carbon hybrid zeolite solid acid microporous material. Taking MFI zeolite treated with formaldehyde as an example, as shown in Figures 1, 2 and 3, the treated MFI zeolite maintains a perfect framework and open pores, and NH ₃ -TPD proves that it has strong acid properties.

The microporous material of the present invention has many advantages such as high activity, high selectivity, mild reaction conditions, easy separation of products and the like as a catalyst and an adsorption separation agent.

The preparation method of the material of the invention is simple, the reaction conditions are mild, and the production cost is low. The obtained all-silicon organic-inorganic hybrid zeolite solid acid can be used as a catalyst, an adsorbent and an alkaline separating agent, has a wide application range and has good industrial application prospects.

Description of drawings

Figure 1 is the XRD pattern of MFI zeolite treated with formaldehyde.

Figure 2 is the NH ₃ -TPD diagram of MFI zeolite treated with formaldehyde.

Fig. 3 is the n-hexane adsorption diagram of MFI zeolite after the action of formaldehyde.

Detailed ways

The present invention is further described below by implementing examples:

Example 1:

The substrate all-silicon MFI type zeolite reacts with formaldehyde according to the following steps to prepare the all-silicon MFI type organic-inorganic carbon hybrid zeolite solid acid:

1. Heat the polyoxymethylene solid at 90°C to 150°C for depolymerization, and collect it with liquid nitrogen.

2. Introduce the vapor of formaldehyde monomer into a container filled with all-silicon MFI zeolite, and react at room temperature for 2 hours to obtain a reaction product. The reaction product is filtered, washed, and dried to obtain an all-silicon MFI organic-inorganic carbon hybrid zeolite solid acid.

Example 2:

The base MFI type zeolite reacts with formaldehyde according to the following steps to prepare the all-silicon MFI type organic-inorganic carbon hybrid zeolite solid acid:

1. Put the polyoxymethylene solid on the bottom of the reactor, and the base material on the upper layer, separated by a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon MFI organic-inorganic carbon hybrid zeolite solid acid.

Example 3:

Substrate MFI type zeolite reacts with acetaldehyde according to the following steps to prepare all-silicon MFI type zeolite solid acid:

1. Mix the acetaldehyde solution with all-silicon MFI zeolite and place it in the reaction kettle. Or put the acetaldehyde solution on the bottom of the reaction kettle, put the base material on the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon MFI organic-inorganic carbon hybrid zeolite solid acid.

Example 4:

The base MFI type zeolite reacts with propionaldehyde according to the following steps to prepare all-silicon MFI type organic-inorganic carbon hybrid zeolite solid acid:

1. Mix the solution of propionaldehyde with all-silicon MFI zeolite and place it in the reaction kettle. Or place the solution of propionaldehyde in the bottom layer of the reaction kettle, place the base material in the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon MFI organic-inorganic carbon hybrid zeolite solid acid.

Example 5:

The base FER type zeolite reacts with formaldehyde according to the following steps to prepare all-silicon FER type organic-inorganic carbon hybrid solid acid:

1. The solid of polyoxymethylene is depolymerized by heating at 90°C to 150°C, and collected with liquid nitrogen.

2. Introduce the vapor of formaldehyde monomer into a container containing all-silicon FER type zeolite, carry out adsorption reaction at room temperature for 2 hours to obtain the reaction product, and the reaction product is filtered, washed, and dried to obtain all-silicon FER type organic-inorganic carbon hybrid zeolite solid acid.

Embodiment 6:

The substrate FER type zeolite reacts with formaldehyde according to the following steps to prepare all-silicon FER type organic-inorganic carbon hybrid zeolite solid acid:

1. Put the polyoxymethylene solid on the bottom of the reactor, and the base material on the upper layer, separated by a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon FER organic-inorganic carbon hybrid zeolite solid acid.

Embodiment 7:

The base FER type zeolite reacts with acetaldehyde according to the following steps to prepare all-silicon FER type organic-inorganic carbon hybrid zeolite solid acid:

1. Mix the acetaldehyde solution with all-silicon FER zeolite and place it in the reaction kettle. Or put the acetaldehyde solution on the bottom of the reaction kettle, put the base material on the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon FER type zeolite organic-inorganic carbon hybrid solid acid.

Embodiment 8:

Substrate FER type zeolite reacts with propionaldehyde according to the following steps to prepare all-silicon FER type organic-inorganic carbon hybrid zeolite solid acid:

1. Mix the solution of propionaldehyde with all-silicon FER zeolite and place it in the reaction kettle. Or place the solution of propionaldehyde in the bottom layer of the reaction kettle, place the base material in the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon FER organic-inorganic carbon hybrid zeolite solid acid.

Embodiment 9:

Substrate all-silicon BEA type (β-type) zeolite reacts with formaldehyde according to the following steps to prepare all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid:

1. The solid formaldehyde is depolymerized by heating at 90°C to 150°C and collected with liquid nitrogen.

2. Introduce the vapor of formaldehyde monomer into a container filled with all-silicon BEA-type zeolite, and carry out adsorption reaction at room temperature for 2 hours to obtain the reaction product, which is filtered, washed, and dried to obtain all-silicon BEA-type organic-inorganic carbon hybrid zeolite solid acid.

Example 10:

The base BEA type zeolite reacts with formaldehyde according to the following steps to prepare all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid:

1. Put the polyoxymethylene solid on the bottom of the reactor, and the base material on the upper layer, separated by a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid.

Example 11:

The base BEA type zeolite reacts with acetaldehyde according to the following steps to prepare all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid:

1. Mix the acetaldehyde solution with all-silicon BEA zeolite and place it in the reaction kettle. Or put the acetaldehyde solution on the bottom of the reaction kettle, put the base material on the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid.

Example 12:

The base BEA type zeolite reacts with propionaldehyde according to the following steps to prepare all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid:

1. Mix the solution of propionaldehyde with all-silicon FER zeolite and place it in the reaction kettle. Or place the solution of propionaldehyde in the bottom layer of the reaction kettle, place the base material in the upper layer, and separate it with a screen in the middle.

2. Put the reaction kettle in an oven at 200°C, and react for 2 days under self-generated pressure. The reaction product is filtered, washed, and dried to obtain an all-silicon BEA type organic-inorganic carbon hybrid zeolite solid acid.

Claims (5)

1, a kind of organic and inorganic carbon hybridized silicon zeolite solid acid cellular material is characterized in that the skeleton oxygen that skeleton contains 1-20% in the oxygen total silicon poromerics is substituted by the aldehydes organo-functional group, and wherein aldehyde radical is RCHO, and R is C here ₀-C ₂Hydro carbons.

2, poromerics according to claim 1 is characterized in that it is the not aluminiferous total silicon zeolite molecular sieve of crystalline state that described skeleton contains the oxygen poromerics.

3, a kind of preparation method of organic and inorganic carbon hybridized silicon zeolite solid acid cellular material as claimed in claim 1, it is characterized in that solid or aqueous solution with oxygen containing total silicon poromerics of skeleton and the agent of aldehydes hydridization, place reactor, carry out hydro-thermal reaction, temperature 20-200 ℃, time 1.5-50 hour, obtain organic and inorganic carbon hybridized silicon zeolite solid acid cellular material.

4, the preparation method of poromerics as claimed in claim 3, when it is characterized in that hydro-thermal reaction the agent of aldehydes hydridization is placed the reactor bottom, the oxygen containing total silicon poromerics of skeleton places the upper strata, the steam and the base material generation gas/solid state reaction that produce when utilizing heating are prepared into organic and inorganic carbon hybridized silicon zeolite solid acid cellular material.

5, poromerics as claimed in claim 1 is in the application of catalysis or separation field.

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