Bimetal modified hybrid silicon film and preparation method and application thereof

Abstract

The invention relates to the field of separation membrane preparation, and discloses a preparation method and application of a bimetallic modified hybrid silicon membrane. The invention relates to a bimetallic modified hybrid silicon membrane. The hybrid silicon membrane comprises a porous support body, a transition layer and a separation layer, the transition layer is prepared from UiO-66-NH2 / SiO2-ZrO2, and the transition layer is prepared from SiO2 and ZrO2; the separation layer comprises a silicon oxide, a first metal and a second metal, the first metal is selected from lanthanide series metal elements, and the second metal is selected from at least one of VIII group metal elements, IIA group metal elements and IIIA group metal elements. The bimetallic modified hybrid silicon film is applied to hydrogen separation, and has high hydrogen selectivity.

Description

Technical Field

[0001] The invention relates to the field of separation membrane preparation, and in particular to a preparation method and application of a bimetallic modified hybrid silicon membrane. Background Art

[0002] In recent years, amorphous silicon membranes with adjustable microstructures have become the most important members of the ceramic membrane family due to their unique permeability and molecular sieving capabilities. Tetraethoxysilane (TEOS)-derived silicon membranes have been widely studied as the first generation of amorphous silicon membranes. As a new generation of silicon-based membranes, organosilicon membranes containing organic and inorganic components are considered to be the most promising candidates for separating H 2 / N 2 The rigid inorganic bond of Si-O-Si bond provides high mechanical strength and thermal stability, while the organic bond of Si-R-Si bond (R represents an organic group) enhances the flexibility and hydrophobicity of the organosilicon membrane. In recent years, the organosilicon membrane with flexible Si-CC-Si bond derived from 1,2-bis(triethoxysilyl)ethane (BTESE) has been shown to have good molecular sieving performance and hydrothermal stability, which makes it promising for small gas separation under hydrothermal conditions.

[0003] Qi et al. [Microporous and Mesoporous Materials 253 (2017) 55-63] further doped metal Pd into BTESE. However, due to the large size of Pd particles, the microporous network of BTESE was damaged, resulting in poor selectivity. Qureshi et al. [J Sol-Gel Sci Technol 2015] doped BTESE with metals such as B, Ta, and Nb. However, due to the relatively open pore structure of B-doped BTESE membrane, its application in the field of gas separation was limited. Ta-BTESE and Nb-BTESE membranes have defect-free pore structures, but their relatively loose pore size distribution results in selectivities of only 7 and 6.5. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem that the hydrogen selectivity of the existing organic silicon membrane needs to be further improved, and to provide a preparation method and application of a bimetallic modified hybrid silicon membrane. The bimetallic modified hybrid silicon membrane of the present invention is applied to hydrogen separation and has high hydrogen selectivity.

[0005] In order to achieve the above-mentioned object, the present invention provides a bimetallic modified hybrid silicon membrane, the hybrid silicon membrane comprises a porous support, a transition layer and a separation layer; the transition layer comprises UiO-66-NH 2 / SiO 2 -ZrO 2Sol; the separation layer comprises silicon oxide, a first metal and a second metal, the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of Group VIII, Group IIA and Group IIIA metal elements.

[0006] Preferably, the average pore size of the porous support is 0.1-1 μm.

[0007] Preferably, the average pore size of the transition layer is 1-5 nm.

[0008] Preferably, the average pore size of the separation layer is 0.4-0.7 nm.

[0009] A second aspect of the present invention provides a method for preparing a bimetallic modified hybrid silicon film, the method comprising:

[0010] (1) reacting an organosilicon source, an acid, a first metal compound and a second metal compound in the presence of a solvent to obtain a bimetallic / organosilicon sol, wherein the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of group VIII, group IIA and group IIIA metal elements;

[0011] (2) UiO-66-NH 2 / SiO 2 -ZrO 2 The sol is coated on a porous support, and then first calcined to obtain a transition layer;

[0012] (3) coating the bimetallic / organic silica sol obtained in step (1) on the transition layer, and then performing a second calcination to obtain a separation layer.

[0013] The third aspect of the present invention provides an application of the bimetallic modified hybrid silicon membrane described in the first aspect or the bimetallic modified hybrid silicon membrane prepared by the preparation method described in the second aspect in gas separation and purification, preferably in hydrogen separation and purification.

[0014] Through the above technical solution, the beneficial effects of the present invention include:

[0015] The bimetallic modified hybrid silicon film provided by the present invention adopts a specific type of bimetallic synergy in a specific ratio to effectively improve the H 2 The bimetallic modified hybrid silicon membrane of the present invention is applied to hydrogen separation and has high hydrogen selectivity. The membrane can effectively solve the problem of (H 2 , CO 2 , O 2 、N 2 , CH 4 、CO) 2 / N 2It can solve the problem of efficient separation and will have good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is the infrared spectra of the LaNi-BTESE dry gel of Example 1 and the BTESE dry gel of Comparative Example 1. DETAILED DESCRIPTION

[0017] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0018] On the one hand, the present invention provides a bimetallic modified hybrid silicon membrane, the hybrid silicon membrane comprises a porous support, a transition layer and a separation layer; the transition layer comprises UiO-66-NH 2 / SiO 2 -ZrO 2 ; The separation layer includes silicon oxide, a first metal and a second metal, the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of Group VIII, Group IIA and Group IIIA metal elements.

[0019] In the bimetallic modified hybrid silicon film of the present invention, the transition layer contains UiO-66-NH 2 / SiO 2 -ZrO 2 , which increases the porosity of the network structure, helps to reduce the resistance of hydrogen passing through the transition layer, further improves the permeability of hydrogen, and at the same time can further improve the hydrothermal stability of the silicone membrane.

[0020] According to the present invention, preferably, the average pore size of the porous support is 0.1-1 μm, for example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm and any value in the range formed by any two of these point values.

[0021] According to the present invention, preferably, the average pore size of the transition layer is 1-5 nm, for example, it can be 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm and any value in the range formed by any two of these point values.

[0022] According to the present invention, preferably, the average pore size of the separation layer is 0.4-0.7 nm, for example, it can be 0.4 nm, 0.45 nm, 0.5 nm, 0.55 nm, 0.6 nm, 0.65 nm, 0.7 nm and any value in the range formed by any two of these point values.

[0023] Controlling the average pore sizes of the porous support, transition layer, and separation layer within the above range is beneficial to improving the separation performance of the obtained bimetallic modified hybrid silicon membrane.

[0024] The average pore diameters of the porous support, transition layer and separation layer of the present invention are measured by the BET method.

[0025] The first metal of the present invention can be various lanthanide metal elements commonly used in the art. Preferably, the first metal is selected from at least one of lanthanum, cerium and neodymium, preferably lanthanum.

[0026] According to the present invention, preferably, the second metal is selected from at least one of cobalt, nickel, magnesium and aluminum, preferably nickel.

[0027] The inventors have found that the use of the above-mentioned specific types of metals synergistically promotes H 2 The surface diffusion of molecules promotes the H 2 The adsorption and transport of molecules is conducive to obtaining higher H 2 Permeability and H 2 / N 2 Permselectivity.

[0028] According to the present invention, preferably, in the separation layer, the ratio of the mass of silicon oxide calculated as silicon element to the total mass of metal calculated as element is 1:0.5-1.5, preferably 1:0.6-1.2. This preferred embodiment is conducive to improving both gas permeability and selectivity.

[0029] Preferably, the mass ratio of the first metal to the second metal is 0.1-1:1, preferably 0.4-0.9:1, calculated as the elements. This preferred embodiment is more conducive to improving both the gas permeability and selectivity. When it is below this range, the gas permeability decreases and the gas selectivity is slightly improved. When it is above this range, the gas permeability increases significantly and the gas selectivity decreases significantly.

[0030] The content of each component in the present invention is calculated by feeding amount.

[0031] According to the present invention, preferably, in UiO-66-NH 2 / SiO 2 -ZrO 2 Medium, UiO-66-NH 2 With SiO 2-ZrO 2 The mass ratio is 0.1-0.5:1.

[0032] According to the present invention, preferably, SiO 2 -ZrO 2 The molar ratio of silicon to zirconium is 1:1-10.

[0033] The porous support of the present invention has a wide range of choices. Preferably, the porous support of the present invention can be selected from at least one of porous ceramics, porous glass, porous metal (such as porous stainless steel), porous quartz and high molecular polymer, more preferably porous ceramics.

[0034] The porous ceramic of the present invention can be selected from conventional ones in the art, for example, Al 2 O 3 、SiO 2 ,BaSO 4 ,BaO,TiO 2 、CuO、MgO、Mg(OH) 2 、LiAlO 2 、ZrO 2 、CNT、BN、SiC、Si 3 N 4 、WC、BC、AlN、Fe 2 O 3 、BaTiO 3 、MoS 2 、V 2 O 5 、PbTiO 3 , TiB 2 、CaSiO 3 In order to improve the separation performance of the separation membrane and based on cost considerations, preferably, the porous support is alumina, preferably α-Al 2 O 3 .

[0035] The present invention has no particular limitation on the source of the porous support, which can be obtained from commercial sources or prepared by conventional methods, as long as the above-mentioned pore size requirements are met.

[0036] The present invention has no particular limitation on the preparation method of the above-mentioned bimetallic modified hybrid silicon membrane, as long as the bimetallic modified hybrid silicon membrane with the above-mentioned characteristics can be prepared. In order to further improve the separation performance of the bimetallic modified hybrid silicon membrane, the present invention also provides a preparation method of the above-mentioned bimetallic modified hybrid silicon membrane.

[0037] A second aspect of the present invention provides a method for preparing a bimetallic modified hybrid silicon film, the method comprising:

[0038] (1) reacting an organosilicon source, an acid, a first metal compound and a second metal compound in the presence of a solvent to obtain a bimetallic / organosilicon sol, wherein the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of group VIII, group IIA and group IIIA metal elements;

[0039] (2) UiO-66-NH 2 / SiO 2 -ZrO 2 The sol is coated on a porous support, and then first calcined to obtain a transition layer;

[0040] (3) coating the bimetallic / organic silica sol obtained in step (1) on the transition layer, and then performing a second calcination to obtain a separation layer.

[0041] In the method provided by the present invention, a specific type of bimetallic synergistic effect is adopted in a specific ratio, and a bimetallic / organic silica sol is prepared by a one-step method to promote H 2 While transferring, the metal is used to 2 The adsorption of H 2 Moreover, since the organic functional groups in the organic silica sol control the permeability and have an adjustable network structure, the bimetallic modified hybrid silicon membrane of the present invention has thermal stability at high temperatures.

[0042] According to the present invention, preferably, the average pore size of the porous support is 0.1-1 μm.

[0043] According to the present invention, preferably, the average pore size of the transition layer is 1-5 nm.

[0044] According to the present invention, preferably, the average pore size of the separation layer is 0.4-0.7 nm.

[0045] According to the present invention, preferably, the reaction conditions in step (1) include: temperature of 25-80° C. and time of 2-30 h.

[0046] According to a preferred embodiment of the present invention, the process of step (1) comprises: firstly subjecting the first metal compound, the second metal compound, the solvent and the acid to a first reaction; and then adding an organosilicon source to a second reaction.

[0047] The present invention has no particular limitation on the order of adding the first metal compound, the second metal compound, the solvent and the acid in the first reaction process, and they can be added separately or together. Preferably, the first metal compound and the second metal compound are first dissolved in the solvent, and then the acid is added.

[0048] Preferably, the conditions of the first reaction include: temperature of 25-50°C and time of 1-12h.

[0049] Preferably, the conditions of the second reaction include: temperature of 25-50° C. and time of 1-12 h.

[0050] Preferably, the first reaction and the second reaction are each independently carried out under stirring conditions.

[0051] The present invention has no particular limitation on the stirring rate, and can be appropriately selected according to specific circumstances, with the goal of achieving uniform mixing and increasing the stirring rate.

[0052] According to the present invention, preferably, the ratio of the mass of the organosilicon source calculated as silicon element to the total mass of the metal compound calculated as metal element is 1:0.5-1.5, preferably 1:0.6-1.2.

[0053] According to the present invention, preferably, the mass ratio of the first metal compound to the second metal compound is 0.1-1:1, preferably 0.4-0.9:1, calculated as elements.

[0054] The first metal of the present invention can be various lanthanide metal elements commonly used in the art. Preferably, the first metal is selected from at least one of lanthanum, cerium and neodymium, preferably lanthanum.

[0055] According to the present invention, preferably, the second metal is selected from at least one of cobalt, nickel, magnesium and aluminum, preferably nickel.

[0056] The present invention has no particular limitation on the types of the first metal compound and the second metal compound, and they can be conventionally selected in the art, as long as they contain the first metal and the second metal. Preferably, the first metal compound and the second metal compound are each independently selected from at least one of nitrates, sulfates and hydrochlorides. For example, cobalt chloride, nickel chloride, aluminum chloride, lanthanum chloride, cobalt nitrate, nickel nitrate, aluminum nitrate, lanthanum nitrate, cobalt sulfate, nickel sulfate, aluminum sulfate, lanthanum sulfate, etc.

[0057] According to the present invention, preferably, the mass ratio of the organosilicon source to the acid calculated as silicon element is 1:0.1-0.5.

[0058] According to the present invention, preferably, the acid is an inorganic acid, preferably at least one selected from nitric acid, sulfuric acid and hydrochloric acid.

[0059] The present invention has a wide range of choices for the type of the organosilicon source, which can be a conventional choice in the art. Preferably, the organosilicon source is 1,2-bis(triethoxysilyl)ethane.

[0060] The present invention has a wide range of choices for the type of solvent, and any solvent that is compatible with and non-reactive with the above-mentioned added substances can be used. In the present invention, ethanol is preferably used.

[0061] According to the present invention, preferably, the mass ratio of the organic silicon source to the solvent is 1:100-200, calculated as silicon element.

[0062] The present invention has no particular limitation on the coating method used in the preparation of the transition layer in step (2), and the coating method can be carried out using conventional methods in the art.

[0063] In order to optimize the coating effect, the present invention preferably adopts a small amount and multiple times method for coating.

[0064] The coating times in the process of forming the transition layer of the present invention are not particularly limited. 2 / SiO 2 -ZrO 2 There is no particular limitation on the amount of sol used, provided that the average pore size of the transition layer obtained is within the range of 1-5 nm.

[0065] According to a specific embodiment of the present invention, the preparation process of the transition layer in step (2) comprises: 2 / SiO 2 -ZrO 2 The sol is coated on a porous support, and then a first calcination is performed, and the coating-first calcination process is repeated to obtain a transition layer.

[0066] According to the present invention, preferably, UiO-66-NH 2 SiO on a dry basis 2 -ZrO 2 The mass ratio of the sol is 0.1-0.5.

[0067] Preferably, SiO 2 -ZrO 2 In the sol, the molar ratio of silicon to zirconium is 1:1-10, for example, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 and any value in the range formed by any two of these values.

[0068] According to the present invention, preferably, the UiO-66-NH 2 / SiO 2 -ZrO 2The concentration of the sol is 0.5-10 wt%.

[0069] The present invention is directed to the UiO-66-NH 2 / SiO 2 -ZrO 2 The source of the sol is not particularly limited and can be purchased from a commercial source or prepared by a conventional method, as long as the above characteristic parameters are met.

[0070] The porous support of the present invention has a wide range of choices. Preferably, the porous support of the present invention can be selected from at least one of porous ceramics, porous glass, porous metal (such as porous stainless steel), porous quartz and high molecular polymer, more preferably porous ceramics.

[0071] The porous ceramic of the present invention can be selected from conventional ones in the art, for example, Al 2 O 3 、SiO 2 ,BaSO 4 ,BaO,TiO 2 、CuO、MgO、Mg(OH) 2 、LiAlO 2 、ZrO 2 、CNT、BN、SiC、Si 3 N 4 、WC、BC、AlN、Fe 2 O 3 、BaTiO 3 、MoS 2 ,α-V 2 O 5 、PbTiO 3 , TiB 2 、CaSiO 3 In order to improve the separation performance of the separation membrane and based on cost considerations, preferably, the porous support is alumina, preferably α-Al 2 O 3 .

[0072] The present invention has no particular limitation on the shape of the porous support, and it can be any common shape, such as a tube, a sheet, a hollow fiber, etc.

[0073] According to the present invention, preferably, the first calcination in step (2) includes: a temperature of 300-400° C. and a time of 20-60 minutes.

[0074] The present invention has no particular limitation on the coating method used in the process of preparing the separation layer in step (3), and the coating method can be carried out using conventional methods in the art.

[0075] In order to optimize the coating effect, the present invention preferably adopts a small amount and multiple times method for coating.

[0076] There is no particular limitation on the number of coating times in the separation layer formation process of the present invention, and there is no particular limitation on the amount of bimetallic / organic silica sol used in the coating process, as long as the average pore size of the separation layer obtained is within the range of 0.4-0.7 nm.

[0077] According to a specific embodiment of the present invention, the preparation process of the separation layer in step (3) includes: coating the bimetallic / organic silica sol obtained in step (1) on the transition layer, then performing a second calcination, and repeating the coating-second calcination process to obtain the separation layer.

[0078] According to the present invention, preferably, the conditions of the second calcination in step (3) include: a temperature of 200-300° C. and a time of 20-60 minutes.

[0079] According to the present invention, preferably, the method further comprises: 2 / SiO 2 -ZrO 2 Before the sol is coated on the porous support, the porous support is first calcined. This preferred embodiment is beneficial for removing impurities on the surface of the porous support and activating the porous support.

[0080] According to the present invention, preferably, the conditions for the calcination treatment include: a temperature of 500-600° C. and a time of 1-10 h.

[0081] When the surface of the porous support is smooth, the porous support can be calcined without polishing.

[0082] When the surface of the porous support is rough, preferably, the method further comprises: first grinding the porous support and then calcining the porous support. This preferred embodiment is conducive to obtaining a porous support with a smooth surface.

[0083] The present invention has no particular limitation on the specific method of polishing, and the polishing can be performed according to conventional methods in the art.

[0084] In the present invention, the "first", "second" and "third" do not limit the substances and operations, but are only used to distinguish the substances introduced in different steps and the operations performed in different stages.

[0085] The third aspect of the present invention provides an application of the bimetallic modified hybrid silicon membrane described in the first aspect or the bimetallic modified hybrid silicon membrane prepared by the preparation method described in the second aspect in gas separation and purification, preferably in hydrogen separation and purification.

[0086] The present invention will be described in detail below through examples.

[0087] In the following examples, UiO-66-NH 2 The commercial product with the brand name XFF32-2 was purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0088] Gas permeability = (gas flux) / (membrane area × pressure difference);

[0089] Where, gas flux, mol / s; membrane area, m 2 ; Pressure difference, Pa;

[0090] H 2 / N 2 Selectivity = H 2 Permeability / N 2 Permeability.

[0091] Example 1

[0092] (1) Preparation of LaNi-BTESE sol: 0.102 g of La(NO 3 ) 3 6H 2 O and 0.201 g Ni(NO 3 ) 3 6H 2 O was dissolved in 8.864 g ethanol, 0.1 g HCl (37 wt%) was added, and the mixture was stirred in a 25°C water bath for 12 h; then 1 g BTESE was added and stirred in a 25°C water bath for 12 h to obtain LaNi-BTESE sol. The sol was calcined at 200°C for 60 min to obtain LaNi-BTESE xerogel for infrared testing.

[0093] (2) Preparation of transition layer: First, a ceramic support (α-Al 2 O 3 , average pore size 0.2 μm) was calcined at 550 ° C for 0.5 h, and then UiO-66-NH 2 / SiO 2 -ZrO 2 Sol (UiO-66-NH 2 / SiO on dry basis 2 -ZrO 2 mass ratio = 0.5, silicon-zirconium molar ratio of 1:4, concentration of 0.5wt%) is coated on the calcined sheet ceramic carrier, and then calcined at 300° C. for 20 min to obtain a transition layer.

[0094] (3) The LaNi-BTESE sol obtained in step (1) is rubbed on the transition layer using absorbent cotton, and then calcined at 200° C. for 60 min to obtain a separation layer. At this time, a bimetallic modified hybrid silicon membrane is obtained.

[0095] The infrared image of the LaNi-BTESE xerogel described in Example 1 is given as an example. Figure 1 The results show the same typical characteristic peaks as those in Comparative Example 1, which indicates that the organosilicon network structure is not destroyed after the introduction of the bimetallic compound.

[0096] The obtained bimetallic modified hybrid silicon film was subjected to gas test. 2 , H 2 The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0097] Example 2

[0098] (1) Preparation of LaCo-BTESE sol: 0.121 g of La(NO 3 ) 3 6H 2 O and 0.166 Co(NO 3 ) 3 6H 2 O was dissolved in 8.864 g of ethanol, 0.1 g of HCl (37 wt%) was added, and the mixture was placed in a 28° C. water bath and stirred for 10 h; then 1 g of BTESE was added and stirred in a 28° C. water bath for 10 h to obtain LaCo-BTESE sol.

[0099] (2) Preparation of transition layer: First, a ceramic support (α-Al 2 O 3 , average pore size 0.2 μm) was calcined at 500 °C for 0.5 h, and then UiO-66-NH 2 / SiO 2 -ZrO 2 Sol (UiO-66-NH 2 / SiO on dry basis 2 -ZrO 2 mass ratio = 0.2, silicon-zirconium molar ratio of 1:6, concentration of 3wt%) is coated on the calcined sheet ceramic carrier, and then calcined at 350° C. for 20 min to obtain a transition layer.

[0100] (3) The LaCo-BTESE sol obtained in step (1) is rubbed on the transition layer using absorbent cotton, and then calcined at 200° C. for 60 min to obtain a separation layer. At this time, a bimetallic modified hybrid silicon membrane is obtained.

[0101] The obtained bimetallic modified hybrid silicon film was subjected to gas test. 2 , H 2 The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0102] Example 3

[0103] (1) Preparation of LaMg-BTESE sol: 0.197 g of La(NO 3 ) 3 6H 2 O and 0.612 g of Mg(NO 3 ) 3 6H 2 O was dissolved in 8.864 g of ethanol, 0.1 g of HCl (37 wt%) was added, and the mixture was placed in a 30° C. water bath and stirred for 14 h; then 1 g of BTESE was added and stirred in a 30° C. water bath for 14 h to obtain LaMg-BTESE sol.

[0104] (2) Preparation of transition layer: First, a ceramic support (α-Al 2 O 3 , average pore size 0.2 μm) was calcined at 600 °C, and then UiO-66-NH 2 / SiO 2 -ZrO 2 Sol (UiO-66-NH 2 / SiO on dry basis 2 -ZrO 2 mass ratio = 0.4, silicon-zirconium molar ratio of 1:10, concentration of 5wt%) is coated on the calcined sheet ceramic carrier, and then calcined at 400° C. for 20 min to obtain a transition layer.

[0105] (3) The LaMg-BTESE sol obtained in step (1) is rubbed on the transition layer with absorbent cotton, and then calcined at 250° C. for 60 min to obtain a separation layer. At this time, a bimetallic modified hybrid silicon membrane is obtained.

[0106] The obtained bimetallic modified hybrid silicon film was subjected to gas test. 2 , H 2 The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0107] Comparative Example 1

[0108] The method of Example 1 was followed, except that the bimetal was not introduced, i.e., step (1) was changed to prepare an organosilicon sol: 1 g of BTESE was dissolved in 15.8 g of ethanol, and then 3 g of water and 0.1 g of HCl (37 wt%) were added, and then the mixture was placed in a 40°C water bath and stirred for 2 h to obtain a BTESE organosilicon solution. The sol was calcined at 200°C for 60 min to obtain a BTESE dry gel for infrared testing.

[0109] The infrared image of the BTESE dry gel described in Comparative Example 1 is given as follows: Figure 1 Shown is 1030cm -1 and 940cm -1 The peaks centered at 3450 cm-1 are the stretching vibrations of siloxane (Si-O-Si) and silanol (Si-OH) bonds, while the peaks at 3450 cm-1 are the stretching vibrations of siloxane (Si-O-Si) and silanol (Si-OH) bonds, respectively. -1 and 1640cm -1 The obvious broad peaks nearby are the stretching vibrations of the hydroxyl (OH) group and adsorbed water. In addition, the -CH 2 The characteristic peak of - bond appears at 2855-2920cm -1 (CH stretching vibration) and 1280-1420cm -1 (CH bending vibration) region, and about 702cm -1 (Si-C stretching vibration) region, which indicates that after calcination at 200 °C, -CH 2 -CH 2 - groups persist in the silicone network.

[0110] The obtained membrane was subjected to gas test. 2 , H 2 The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0111] Comparative Example 2

[0112] The method of Example 1 was followed, except that step (1) was changed to: 0.212 g of La(NO 3 ) 3 6H 2 O was dissolved in 9 g of ethanol, 0.1 g of HCl (37 wt%) was added, and the mixture was stirred in a 25°C water bath for 12 h; then 1 g of BTESE was added and stirred in a 25°C water bath for 12 h to obtain La-BTESE sol.

[0113] The obtained metal modified hybrid silicon film was subjected to gas test. 2 , H 2The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0114] Comparative Example 3

[0115] The method of Example 1 was followed, except that step (1) was changed to: 0.347 g of Ni(NO 3 ) 3 6H 2 O was dissolved in 9 g of ethanol, 0.1 g of HCl (37 wt%) was added, and the mixture was stirred in a 25°C water bath for 12 h; then 1 g of BTESE was added and stirred in a 25°C water bath for 12 h to obtain Ni-BTESE sol.

[0116] The obtained metal modified hybrid silicon film was subjected to gas test. 2 , H 2 The gas was continuously introduced into the membrane module heated at 200°C, and the gauge pressure on the feed side was controlled at 200 kPa. After stabilization for 1 hour, the permeability and selectivity were measured. The results are shown in Table 2.

[0117] Table 1

[0118]

[0119]

[0120] Note: A represents the ratio of the mass of silicon oxide in the separation layer in terms of silicon element to the total mass of metal in terms of element.

[0121] Table 2

[0122]

[0123] It can be seen from the results in Table 2 that the bimetallic modified hybrid silicon membrane of the present invention is applied to hydrogen separation, which has significantly higher H 2 / N 2 Selective.

[0124] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A bimetallic modified hybrid silicon membrane, the hybrid silicon membrane comprising a porous support, a transition layer and a separation layer; the transition layer comprises UiO-66-NH2 / SiO2-ZrO2; the separation layer comprises silicon oxide, a first metal and a second metal, the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of Group VIII, Group IIA and Group IIIA metal elements.

2. The hybrid silicon film according to claim 1, wherein The average pore size of the porous support is 0.1-1 μm; Preferably, the average pore size of the transition layer is 1-5 nm; Preferably, the average pore size of the separation layer is 0.4-0.7 nm.

3. The hybrid silicon film according to claim 1 or 2, wherein: The first metal is selected from at least one of lanthanum, cerium and neodymium, preferably lanthanum; Preferably, the second metal is selected from at least one of cobalt, nickel, magnesium and aluminum, preferably nickel; Preferably, in the separation layer, the ratio of the mass of silicon oxide calculated as silicon element to the total mass of metal calculated as element is 1:0.5-1.5, preferably 1:0.6-1.2; Preferably, the mass ratio of the first metal to the second metal is 0.1-1:1, preferably 0.4-0.9:1, calculated as elements; Preferably, in UiO-66-NH2 / SiO2-ZrO2, the mass ratio of UiO-66-NH2 to SiO2-ZrO2 is 0.1-0.5:1; Preferably, in SiO2-ZrO2, the molar ratio of silicon to zirconium is 1:1-10; Preferably, the porous support is alumina.

4. A method for preparing a bimetallic modified hybrid silicon film, the method comprising: (1) reacting an organosilicon source, an acid, a first metal compound and a second metal compound in the presence of a solvent to obtain a bimetallic / organosilicon sol, wherein the first metal is selected from lanthanide metal elements, and the second metal is selected from at least one of group VIII, group IIA and group IIIA metal elements; (2) coating the UiO-66-NH2 / SiO2-ZrO2 sol onto a porous support, and then performing a first calcination to obtain a transition layer; (3) coating the bimetallic / organic silica sol obtained in step (1) on the transition layer, and then performing a second calcination to obtain a separation layer.

5. The method according to claim 4, wherein: The average pore size of the porous support is 0.1-1 μm; Preferably, the average pore size of the transition layer is 1-5 nm; Preferably, the average pore size of the separation layer is 0.4-0.7 nm.

6. The method according to claim 4, wherein: The reaction conditions of step (1) include: temperature of 25-80°C and time of 2-30h; Preferably, the ratio of the mass of the organosilicon source calculated as silicon element to the total mass of the metal compound calculated as metal element is 1:0.5-1.5, preferably 1:0.6-1.2; Preferably, the mass ratio of the first metal compound to the second metal compound is 0.1-1:1, preferably 0.4-0.9:1, calculated on an element basis; Preferably, the first metal is selected from at least one of lanthanum, cerium and neodymium, preferably lanthanum; Preferably, the second metal is selected from at least one of cobalt, nickel, magnesium and aluminum, preferably nickel; Preferably, the first metal compound and the second metal compound are each independently selected from at least one of nitrates, sulfates and hydrochlorides.

7. The method according to any one of claims 4 to 6, wherein: The mass ratio of the organosilicon source to the acid, calculated on the basis of silicon element, is 1:0.1-0.5; Preferably, the acid is an inorganic acid, preferably at least one selected from nitric acid, sulfuric acid and hydrochloric acid; Preferably, the organosilicon source is 1,2-bis(triethoxysilyl)ethane.

8. The method according to any one of claims 4 to 7, wherein: The mass ratio of UiO-66-NH2 to SiO2-ZrO2 sol on a dry basis is 0.1-0.5; Preferably, in the SiO2-ZrO2 sol, the molar ratio of silicon to zirconium is 1:1-10; Preferably, the concentration of the UiO-66-NH2 / SiO2-ZrO2 sol is 0.5-10wt%; Preferably, the porous support is alumina; Preferably, the conditions of the first calcination in step (2) include: a temperature of 300-400° C. and a time of 20-60 minutes; Preferably, the conditions for the second calcination in step (3) include: a temperature of 200-300° C. and a time of 20-60 minutes.

9. The method according to any one of claims 4 to 8, wherein: The method further comprises: before coating the UiO-66-NH2 / SiO2-ZrO2 sol on the porous support, firstly calcining the porous support; Preferably, the calcination treatment conditions include: a temperature of 500-600° C. and a time of 1-10 h.

10. Use of the bimetallic modified hybrid silicon membrane according to any one of claims 1 to 3 or the bimetallic modified hybrid silicon membrane prepared by the preparation method according to any one of claims 4 to 9 in gas separation and purification, preferably in hydrogen separation and purification.

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