阅读说明：本技术 金属有机骨架基微膜反应器、制备方法及应用 (Metal organic framework-based micro-membrane reactor, preparation method and application ) 是由 杨经伦 何凯琳 韩伟 于 2019-04-04 设计创作，主要内容包括：本发明公开了一种金属有机骨架基微膜反应器的制备方法,包括以下步骤：准备纤维膜基质；在纤维膜上生长金属有机骨架膜；将长有金属有机骨架的纤维膜装配到微膜反应器中。相比于平面基底,本发明通过纤维式基底提供了更大的表面积,所以,将金属有机骨架纳米颗粒限制于或将其生长于纤维基底上可以提高表面积,因此增加了催化活性位点；此外,纤维膜的粗糙的表面和多孔的内部空间可以视为微流道,促进催化反应的传质和传热过程。(The invention discloses a preparation method of a metal organic framework-based micro-membrane reactor, which comprises the following steps: preparing a fiber membrane substrate; growing a metal organic framework film on the fiber film; the fiber membrane with the metal organic framework is assembled into a micro-membrane reactor. Compared with a plane substrate, the invention provides larger surface area by the fiber substrate, so that the surface area can be increased by limiting or growing the metal organic framework nano particles on the fiber substrate, thereby increasing the catalytic active sites; in addition, the rough surface and porous internal space of the fiber membrane can be regarded as micro flow channels, promoting mass and heat transfer processes of catalytic reactions.)

1. A preparation method of a metal organic framework-based micro-membrane reactor is characterized by comprising the following steps:

preparing a fiber membrane substrate;

growing a metal organic framework film on the fiber film; and

the metal organic framework membrane is assembled into a micro-membrane reactor.

2. The method of claim 1 wherein the fiber matrix is selected from the group consisting of glass fiber substrate, carbon cloth, carbon paper, and cellulose paper.

3. The method of claim 1 wherein the metal organic framework-based micro membrane reactor is selected from the group consisting of ZIF-8, FeBDC, CuBDC, HKUST-1 and uo-66.

4. The method of preparing a metal-organic framework-based micro-membrane reactor of claim 1, wherein the metal-organic framework membrane is prepared by an in-situ growth method, a secondary growth method and a modified secondary growth method.

5. The method of preparing a metal-organic framework-based micro-membrane reactor of claim 1, wherein the micro-membrane reactor is assembled in a square plate type or a tube type, and the assembly of the tube type micro-membrane reactor includes a roll-to-roll method and a stack method.

6. A metal-organic framework-based micro-membrane reactor, characterized by being prepared by the process of claims 1-5.

7. Use of a metal organic framework based micro-membrane reactor prepared according to the method of claims 1-5 in catalytic reactions, wherein the catalytic reactions comprise condensation, reduction and acetalization reactions.

8. Use according to claim 7, wherein the condensation reaction is a Knoevenagel condensation reaction between benzaldehyde and ethyl cyanoacetate.

9. Use according to claim 7, wherein the reduction is a 4-nitrophenol reduction.

10. Use according to claim 7, characterized in that the acetalisation reaction is an acetalisation reaction between benzaldehyde and methanol.

Technical Field

The invention relates to a metal organic framework based catalytic membrane reactor, which comprises the preparation of a metal organic framework membrane, the design and the assembly of a microreactor and the application in catalytic reaction.

Background

Metal organic frameworks and noble metal doped metal organic frameworks are potential catalysts in organic reactions. Large areas of metal organic framework nanoparticles provide sufficient catalytically active sites. However, in the tank reaction, the nanoparticle catalyst is difficult to separate and reuse; in fixed bed reactions, they also bring about a high pressure drop. The catalytic membrane reactor integrating reaction and separation can increase reaction conversion rate, improve selectivity, simplify product separation and promote the process of continuous reaction. However, low loading and small active surface area are major weaknesses of catalytic membrane materials.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a metal organic framework based micro-membrane reactor and its application in catalytic reaction to promote the mixing of reactants and catalyst, obtain high yield in a short time, and do not need to separate catalyst.

The technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method for constructing the metal organic framework-based micro-membrane reactor comprises the following steps:

preparing a fiber membrane substrate;

growing a metal organic framework film on the fiber film; and

the metal organic framework membrane is assembled into a micro-membrane reactor.

In the preparation method of the metal organic framework-based micro-membrane reactor provided by the invention, the fiber matrix is selected from glass fiber base materials, carbon cloth, carbon paper and cellulose paper.

In the preparation method of the metal organic framework-based micro-membrane reactor provided by the invention, the metal organic framework is selected from ZIF-8, FeBDC, CuBDC, HKUST-1 and UiO-66.

In the preparation method of the metal organic framework-based micro-membrane reactor provided by the invention, the metal organic framework membrane is prepared by an in-situ method, a secondary growth method and an improved secondary growth method.

In the preparation method of the metal organic framework-based micro-membrane reactor provided by the invention, the assembled micro-membrane reactor is a square plate type or a tubular type, and the assembly of the tubular type micro-membrane reactor comprises a coiling method and a stacking method.

Correspondingly, the invention also provides the metal organic framework-based micro-membrane reactor prepared by the preparation method.

Correspondingly, the invention also provides the application of the metal organic framework-based micro-membrane reactor prepared by the preparation method in catalytic reactions, wherein the catalytic reactions comprise condensation reaction, reduction reaction and acetalization reaction.

In the application provided by the invention, the condensation reaction is Knoevenagel condensation reaction between benzaldehyde and ethyl cyanoacetate.

In the application provided by the invention, the reduction reaction is a 4-nitrophenol reduction reaction.

In the application provided by the invention, the acetalization reaction is an acetalization reaction between benzaldehyde and methanol.

The metal organic framework-based micro-membrane reactor, the preparation method and the application have the following beneficial effects: compared with a plane substrate, the invention provides larger surface area by the fiber substrate, so that the surface area can be increased by limiting or growing the metal organic framework nano particles on the fiber substrate, thereby increasing the catalytic active sites; in addition, the rough surface and porous internal space of the fiber membrane can be regarded as micro flow channels, promoting mass and heat transfer processes of catalytic reactions.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts:

FIGS. 1A, 1B and 1C are schematic views illustrating a process for preparing a metal-organic framework film, wherein FIG. 1A shows an in-situ growth method; FIG. 1B is a secondary growth method; FIG. 1C is a modified overgrowth process for noble metal doping;

FIGS. 2A and 2B are schematic representations of a method of assembling a microreactor, wherein FIG. 2A shows a microreactor cross-sectional configuration and FIG. 2B shows a different reactor design, including a square-shaped flat-plate and a tubular microreactor; the tubular reactor comprises a metal organic framework fiber membrane wound inside or stacked layer by layer;

FIGS. 3A and 3B show a catalytic activity test apparatus, wherein FIG. 3A is an aldolization reaction and a Knoevenagel condensation reaction; FIG. 3B is a reduction of p-nitrophenol;

FIGS. 4A-K are scanning electron microscope images and energy dispersive X-ray spectral element distribution images, wherein FIG. 4A is a FeBDC film surface; FIG. 4B is a UiO-66 film (solution 1) prepared by in situ growth; FIG. 4C a UiO-66 film (solution 2) prepared using an in situ growth method; FIG. 4D is a HKUST-1 membrane; FIG. 4E is a ZIF-8 membrane grown without ethanol wetting; FIGS. 4F, 4G and 4H are ZIF-8 membranes prepared by wetting with ethanol; FIGS. 4J and 4K are energy dispersive X-ray spectroscopy elemental distribution images of the ZIF-8 film of FIG. 4I;

FIGS. 5A and 5B are the surface and interior of ZIF-8 membranes (not wetted with ethanol) after 4 hours of flow reaction;

FIGS. 6A-D are scanning electron microscope images and energy dispersive X-ray spectroscopy elemental distribution images of Pd/ZIF-8 with a Pd loading of 3.1 mol%;

FIGS. 7A, 7B and 7C are X-ray diffraction (XRD) patterns of FeBDC, ZIF-8 and Pd/ZIF-8 films, respectively;

FIGS. 8A and 8B compare ZIF-8 loading of ZIF-8 glass fiber membranes obtained from different manufacturing methods, including whether the hydrophobic glass fiber membranes were ethanol soaked and whether the glass fiber membranes were hydrophobic;

FIGS. 9A, 9B and 9C are Fourier Transform Infrared (FTIR) spectra of FeBDC, ZIF-8 and CuBTC films;

FIGS. 10A-C show benzaldehyde conversion in a tank reactor and a microreactor, wherein FIG. 10A shows benzaldehyde conversion of different MOF membranes in a tank reactor; fig. 10B is the catalytic results of a microreactor and a tank reactor for a febec c membrane; fig. 10C shows benzaldehyde conversion of zrbc and CuBTC membranes in a flow microreactor;

FIGS. 11A-C are the results of Knoevenagel reactions with ZIF-8 membranes grown on hydrophobic glass fiber substrates; FIG. 11A is the catalytic results for a ZIF-8 membrane reactor in three runs (15 wt% ZIF-8 loading, reaction at 60 ℃ C., 1 hour residence time); FIG. 11B is the catalytic results for a ZIF-8 membrane reactor (7 wt% ZIF-8 loading, reaction at 60 ℃ C., 1 hour residence time); FIG. 11C is the catalytic results for a ZIF-8 membrane reactor (15 wt% ZIF-8 loading, reaction at 22 ℃ C. with 1 hour residence time);

FIG. 12 is the 4-nitrophenol reduction of a Pd/ZIF-8MOF membrane microreactor, where FIG. 12A is the catalytic results of a Pd/ZIF-8 membrane reactor prepared using a 0.6 mol% Pd suspension; FIG. 12B is the catalytic results of a Pd/ZIF-8 membrane reactor prepared using a 3 mol% Pd suspension.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Exemplary embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to the drawings and the specific embodiments in the specification, and it should be understood that the embodiments and the specific features in the embodiments of the present invention are detailed descriptions of the technical solution of the present application, and are not limited to the technical solution of the present application, and the technical features in the embodiments and the examples of the present invention may be combined with each other without conflict.

The invention provides a preparation method of a metal organic framework-based micro-membrane reactor, which comprises the following steps: preparing a fiber membrane substrate; growing a metal organic framework film on the fiber film; and assembling the metal-organic framework membrane into a micro-membrane reactor.

The metal organic framework film is prepared by an in-situ growth method and a secondary growth method, or a modified secondary growth method is used for doping noble metal into the metal organic framework film. A tightly packaged metal-organic framework-based micro-membrane reactor is prepared through superposing a cover plate with inlet and outlet on a metal-organic framework membrane, and packaging with polydimethyl siloxane. The rough surface and porous structure of the fibrous substrate can be considered as micro flow channels for organic reactions. The fibrous substrate may simultaneously confine the metal-organic framework particles therein and support the growth of the metal-organic framework layer on the fiber surface to provide sufficient catalyst loading for the catalytic membrane reactor. The microreactor further promotes mass transfer and heat transfer, so that the microreactor has higher reaction efficiency.

FIGS. 1A-C show several methods for preparing metal organic framework fiberglass membranes. FIG. 1A shows an in situ growth method. FIG. 1B is a secondary growth method comprising: (1) pretreatment of the fiber membrane (whether ethanol soaking is adopted or not); (2) growing and washing seed crystals; (3) growing and washing. FIG. 1C shows a modified overgrowth process for noble metal doping, comprising: (1) pretreatment of fiber membranes (ethanol soaking); (2) growing and washing seed crystals; (3) doping with ethanol suspension of palladium, and evaporating the ethanol solution; (4) and (5) growing and washing.