Surface loading method of porous material and application thereof

Abstract

The invention relates to the technical field of preparation of catalysts, and discloses a surface loading method of a porous material and application thereof, the method comprises the following steps: (1) contacting the porous material with an organic matter, and adsorbing the organic matter into pores of the porous material; wherein the boiling point of the organic matter is 100-250 DEG C; (2) introducing a to-be-loaded component to a product obtained in the step (1); and (3) removing organic matters in the product obtained in the step (2). The method can effectively control the loading depth of the surface of the porous material, so that the utilization rate of loaded components is improved.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a surface loading method of a porous material and application thereof. Background Art

[0002] The loaded components in the loaded catalyst are usually introduced directly into the catalyst matrix, or in the slurry process, or by direct impregnation. In the loaded catalyst with porous materials as the matrix or carrier, the loaded components will inevitably enter the pores of the porous material during the conventional introduction process, resulting in blockage of the micropores and mesopores, and the pores are not conducive to the activity of the loaded components, and may also lead to an increase in the catalyst coking tendency and an increase in the coke yield. For example, in catalytic cracking catalysts, rare earths such as La and Ce are used to improve the nickel tolerance of the catalyst for anti-metals, but since the contaminated nickel is mainly distributed in the outermost layer of the catalytic cracking catalyst, most of the rare earth metals inside the particles cannot play a corresponding anti-nickel role, and even some rare earth metals are introduced too much into the catalyst, which will lead to an increase in the catalyst coking tendency and an increase in the coke yield.

[0003] Therefore, how to control the loading depth of the supported components in the supported catalyst is an important issue in regulating the activity of the catalyst. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art that the loading depth of components loaded on porous materials is difficult to control and the utilization rate of loaded components is low, and to provide a surface loading method for porous materials and its application. This method can effectively control the loading depth of components loaded on the surface of porous materials, load the components to be loaded on the outer surface of the porous material, and thereby improve the utilization rate of the loaded components.

[0005] In order to achieve the above object, the present invention provides a surface loading method of a porous material, the method comprising:

[0006] (1) contacting the porous material with the organic matter, and adsorbing the organic matter into the pores of the porous material;

[0007] Wherein, the boiling point of the organic matter is 100-250°C;

[0008] (2) introducing the component to be loaded onto the product obtained in step (1);

[0009] (3) Removing organic matter from the product obtained in step (2).

[0010] Another aspect of the present invention provides application of the surface loading method of the porous material in catalyst preparation.

[0011] In the existing catalyst preparation process, metal or non-metal components are usually introduced directly in the preparation process of the catalyst matrix, the pulping process, or by direct dipping or spraying. However, since the porous material usually contains more mesopores and micropores, in the conventional dipping or spraying process, the loaded component tends to enter the interior of the catalyst particles through the pores, and the loading depth is difficult to control, resulting in the inability of the loaded component to play the corresponding function and effect, and the utilization rate of the loaded component is low. In the present invention, the porous material is first subjected to organic adsorption, the organic matter is adsorbed into the micropores and mesopores of the porous material, and then the conventional method is used to load the component to be loaded, and then the organic matter is removed by heat treatment or vacuum desorption, so that the loaded component can be reduced as much as possible to block the micropores or mesopores, and the loading depth on the surface of the porous material is effectively controlled, thereby improving the utilization rate of the loaded component. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a cross-sectional element electron probe micro-area analysis picture of the porous material C1 with lanthanum oxide loaded on the surface prepared in Example 1 of the present invention;

[0013] Figure 2 1 is a line scan distribution diagram of elements of a cross section of the porous material C1 loaded with lanthanum oxide on the surface prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0014] 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.

[0015] In one aspect, the present invention provides a method for surface loading of a porous material, the method comprising:

[0016] (1) contacting the porous material with the organic matter, and adsorbing the organic matter into the pores of the porous material;

[0017] Wherein, the boiling point of the organic matter is 100-250°C;

[0018] (2) introducing the component to be loaded onto the product obtained in step (1);

[0019] (3) Removing organic matter from the product obtained in step (2).

[0020] In the existing catalyst preparation process, metal or non-metal components are often introduced by direct impregnation, spraying or coprecipitation. However, since porous materials usually contain more mesopores and micropores, in the conventional impregnation, spraying or coprecipitation process, the loaded components often enter the interior of the catalyst particles through the pores, and the loading depth is difficult to control, resulting in the inability of the loaded components to play the corresponding functions and effects, and the utilization rate of the loaded components is low. In the present invention, the porous material is first subjected to organic adsorption, and the organic matter is adsorbed into the micropores and mesopores of the porous material, and then the components to be loaded are loaded in a conventional manner, and then the organic matter is removed, so that the loaded components can be reduced as much as possible from entering the micropores or mesopores, avoiding pore blockage, and effectively controlling the loading depth on the surface of the porous material, thereby improving the utilization rate of the loaded components.

[0021] According to the present invention, the surface loading method can be used to control the average loading depth of the loaded component to not exceed 25% of the particle radius, preferably 10-20%. The loaded porous material is observed by EPMA, adjusted to have 10-50 particles in the field of view, and any particle is selected. The ratio of the distance from the outer edge of the particle section to the position where the content of the loaded component reaches 80wt% of the total loading amount on the radius to the particle radius is recorded as the loading depth of the loaded component on the radius, and 4 different radii are selected from each particle to perform element line scanning distribution statistics on the loading depth, and the average value is calculated and recorded as the loading depth of the loaded component in the porous material; then the average value of the loading depth of the loaded component in 5 different particles within the field of view is calculated according to the above method, and recorded as the average loading depth of the rare earth metal component in the porous material.

[0022] According to the present invention, the boiling point of the organic matter is 100-250°C, for example, it can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, etc., typical but not limiting boiling points or ranges between the two. The organic matter within the above boiling point range is used for adsorption. On the one hand, the organic matter has a suitable molecular weight and volume size, which is conducive to adsorbing the organic matter into the micropores and mesopores of the porous material, and is conducive to controlling the loading depth of the porous material surface; on the other hand, within the above boiling point range, the organic matter can be removed at a relatively low heat treatment temperature, thereby helping to improve the surface loading effect of the porous material. Preferably, the boiling point of the organic matter is 110-200°C. The use of the above preferred embodiment is conducive to further improving the loading effect on the surface of the porous material and improving the utilization rate of the components to be loaded.

[0023] The present invention has a wide range of selection for the specific type of the organic matter, as long as it meets the above boiling point range. The organic matter can be a hydrocarbon, and can also contain heteroatoms such as S, P or N, and the present invention has no special limitation on this.

[0024] According to some preferred embodiments of the present invention, the organic matter is selected from substituted or unsubstituted aromatic hydrocarbons and / or alkanes, and optionally, at least one carbon atom in the aromatic hydrocarbons or alkanes is substituted by S, P or N. The substituent in the substituted aromatic hydrocarbons or alkanes may be, for example, methyl and / or ethyl.

[0025] Preferably, the organic matter is selected from at least one of benzene, toluene, ethylbenzene, xylene, trimethylbenzene, trimethylphosphine, picoline and trimethylpyridine. It is understandable that the organic matter listed above also includes any isomers thereof, for example, xylene includes o-xylene, m-xylene and p-xylene, which are well known to those skilled in the art. The adoption of the above preferred embodiment is conducive to further reducing the micropores or mesopores of the porous material into which the components to be loaded enter, helping the components to be loaded to have a suitable loading depth and improving the utilization rate of the components to be loaded.

[0026] In a further preferred embodiment, the organic matter is selected from at least one of toluene, xylene and ethylbenzene.

[0027] The present invention has a wide selection range for the adsorption amount of the organic matter. It can be understood that in the present invention, the loading depth of the component to be loaded can be further controlled by controlling the adsorption amount of the organic matter. Those skilled in the art can make adjustments according to the actual needs of the catalyst.

[0028] According to some preferred embodiments of the present invention, based on the water droplet pore volume of the porous material, the adsorption amount of the organic matter is 20-95 vol%, preferably 40-80 vol%. Controlling the adsorption amount of the organic matter within the above range is conducive to the controllable distribution depth dispersion of the loaded metal.

[0029] In the present invention, the water droplet pore volume of micron-sized porous materials is measured by the water drop method for catalytic cracking catalyst pore volume determination in NB / SH / T 0955-2017. The porous material particles of millimeter size and above can be measured by combining the macropore volume measured by mercury intrusion method and the micropore volume measured by BET method.

[0030] In the present invention, the "porous material" refers to a material with a network structure consisting of mutually interpenetrating or closed holes, and has mesopores and / or micropores. "Micropores" refer to pores with a pore size of less than 2nm; "mesopores" refer to pores with a pore size between 2-50nm, and "macroporous" refers to pores with a pore size greater than 50nm. The present invention has a wide range of choices for the porous material, which can be a porous matrix / carrier, or a porous catalyst, etc., all of which can be applicable to the surface loading method provided by the present invention.

[0031] According to some preferred embodiments of the present invention, the porous material is selected from at least one of molecular sieves, porous inorganic oxides and porous clays. The molecular sieve is preferably at least one of pure silicon molecular sieve, silicon aluminum molecular sieve, silicon aluminum phosphorus molecular sieve, titanium silicon molecular sieve and silicon phosphorus molecular sieve, for example, it can be at least one of Y-type molecular sieve, A-type molecular sieve, ZRP molecular sieve and SAPO molecular sieve. Preferably, the porous inorganic oxide is selected from at least one of porous metal oxides, for example, it can be at least one of aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide and titanium oxide.

[0032] The porous material may also be a mixture of molecular sieves and inorganic oxides. The present invention has no particular limitation on the content of the two, as long as it has the above-mentioned pore structure.

[0033] According to some preferred embodiments of the present invention, the total pore volume of the porous material is 0.1-0.8 mL / g, preferably 0.2-0.6 mL / g.

[0034] Preferably, in the porous material, the pore volume of micropores and mesopores accounts for 30-100% of the total pore volume, preferably 50-95%; the pore volume of macropores accounts for 0-70% of the total pore volume, preferably 5-50%.

[0035] In the present invention, the total pore volume and pore distribution of the porous material are measured by the BET method.

[0036] In the present invention, the contacting in step (1) can be carried out under vacuum conditions or non-vacuum conditions. Preferably, the contacting in step (1) is carried out under vacuum conditions. Preferably, the vacuum conditions include: an absolute pressure of 1×10 -5 The preferred embodiment described above is advantageous for the organic material to first fill the micropores and mesopores, and then gradually diffuse from the mesopores to the macropores. The pore filling is distributed in a stepped manner, which is advantageous for improving the uniformity of the adsorption of organic matter and further improving the more uniform loading depth of the components to be loaded.

[0037] According to some preferred embodiments of the present invention, the contacting method in step (1) includes: contacting the atmosphere containing organic matter with the porous material under vacuum conditions. Specifically, the porous material may be first subjected to vacuum treatment, and then the atmosphere containing organic matter is introduced to adsorb the organic matter into the pores of the porous material.

[0038] The present invention has no particular limitation on the specific method of introducing the component to be loaded in step (2), and the loading method conventional in the art can be used, for example, the component to be loaded can be introduced by impregnation, spraying or coprecipitation. The impregnation, spraying or coprecipitation can be carried out by conventional operation methods and conditions in the art, and the present invention has no particular limitation on this.

[0039] In order to obtain a more suitable loading depth and avoid organic matter blocking the pores, improve the dispersion of the surface loaded components, and avoid particle agglomeration, preferably, the method of introducing the components to be loaded onto the product obtained in step (1) includes: impregnating or spraying a solution containing a precursor of the components to be loaded onto the product obtained in step (1), and then drying. Although the coprecipitation method can also control a lower average loading depth of the loaded components, the particles are prone to agglomeration into clusters of hundreds of nanometers, which is not conducive to exerting activity.

[0040] According to the present invention, the solution containing the precursor of the component to be loaded also contains a solvent. Preferably, the boiling point of the solvent in the solution containing the precursor of the component to be loaded is lower than the boiling point of the organic matter. In the above preferred case, it is beneficial to control the loading depth of the component to be loaded, ensure that the component to be loaded is preferentially loaded on the outer surface and part of the macropore surface, and avoid blocking the mesopores and micropores; preferably, the boiling point of the solvent in the solution containing the precursor of the component to be loaded is 10-150°C lower than the boiling point of the organic matter.

[0041] According to the present invention, preferably, at 25° C., the solubility of the solvent in the solution containing the precursor of the component to be loaded in 100 g of organic matter is not higher than 0.5 g, preferably not higher than 0.1 g; in the above preferred case, it is beneficial to improve the utilization rate of the component to be loaded and avoid component loss.

[0042] The present invention has no special restrictions on the specific types of the components to be loaded, and those skilled in the art can make a selection according to actual needs. The components to be loaded can be metal components and / or non-metal components. The present invention has no special requirements for the selection of the precursors of the components to be loaded, as long as the components to be loaded can be provided. For example, it can be a soluble compound of the components to be loaded. When the components to be loaded are metal components, for example, it can be at least one of the chlorides, sulfates, and nitrates of the metal, which are well known to those skilled in the art and will not be repeated here. The present invention has no special restrictions on the concentration of the solution containing the precursors of the components to be loaded. Preferably, the concentration of the solution containing the precursors of the components to be loaded is 1-30wt%.

[0043] The present invention has a wide range of selection for the amount of the component to be loaded, and those skilled in the art can select it according to actual needs. In order to ensure the dispersion of the component to be loaded on the surface of the porous material and to avoid blocking the micropores and mesopores of the porous material as much as possible, preferably, based on the mass of the porous material, the amount of the component to be loaded is 0.01-6wt%, preferably 0.1-4wt%.

[0044] According to the present invention, preferably, the drying temperature is 80-250° C. and the drying time is 10-250 min.

[0045] In a further preferred embodiment, the drying includes a low-temperature drying stage and a high-temperature drying stage, wherein the temperature of the low-temperature drying stage is 80-110°C, the time is 1-100 min, and the heating rate is 1-20°C / min; the temperature of the high-temperature drying stage is 110-250°C, the time is 10-120 min, and the heating rate is 1-20°C / min. The above preferred embodiment is adopted, through slow heating and stage drying, which is conducive to the stable fixation of the loaded component on the surface of the inorganic porous material.

[0046] Preferably, the drying is performed under an inert atmosphere, which is preferably provided by nitrogen.

[0047] The present invention has no particular requirements for the specific method of removing the organic matter in the product obtained in step (2) in step (3). For example, the organic matter can be removed by heat treatment or vacuum desorption.

[0048] According to some preferred embodiments of the present invention, the heat treatment conditions include: a temperature of 250-500° C., preferably 250-400° C.; and a time of 10-180 min, preferably 30-120 min.

[0049] According to some preferred embodiments of the present invention, the vacuum desorption conditions include: an absolute pressure of 1×10 - 5 Pa to 1Pa, preferably 1×10 -4 Pa to 0.1 Pa; the temperature of vacuum desorption is 20-30°C, preferably at room temperature.

[0050] The use of the above preferred embodiment to remove organic matter from the product obtained in step (2) is beneficial to improving the removal efficiency of organic matter and avoiding the loss of loaded components.

[0051] Another aspect of the present invention provides application of the surface loading method of the porous material in catalyst preparation.

[0052] The surface loading method of porous materials provided by the present invention can be applied, for example, in the preparation process of catalytic cracking catalysts, to load active components and / or auxiliary components on only the outer surface and part of the macropore surface of the catalyst matrix or carrier.

[0053] The present invention will be described in detail below through examples.

[0054] In the following examples, unless otherwise specified, the raw materials used were commercially available.

[0055] Example 1

[0056] (1) Preparation of porous materials:

[0057] Take 20 parts by mass of pseudo-boehmite (on a dry basis, a product of Shandong Aluminum Company), acidify and then slurry to prepare an acidified boehmite with a solid content of 12% by mass; then add 10 parts by mass of aluminum sol (on a dry basis), 34 parts by mass of kaolin (on a dry basis) and 36 parts by mass of DASY.2.0 molecular sieve (a product of Qilu Branch of Sinopec Catalyst Co., Ltd., with a molar ratio of silicon oxide to aluminum oxide of 10.8), stir for 0.5h, spray dry, roast at 550°C for 2h, wash twice with a 2% by mass ammonium chloride solution, and dry. The prepared porous material is recorded as A1. The total pore volume of porous material A1 is 0.45mL / g, the proportion of micropores and mesopores in the total pore volume is 85%, and the proportion of macropores is 15%.

[0058] (2) A 30 mL vacuum treatment reactor is used, wherein the vacuum treatment reactor is a sealable quartz chamber, wherein a connecting valve A is connected to a vacuum pump, another connecting valve B is connected to a xylene storage tube, and there is also a vent valve C.

[0059] 10 g of porous material A1 (dry basis) was placed in a 30 mL vacuum reactor. After closing the vent valve and connector B, connector A was opened and the vacuum pump was turned on for vacuum treatment. When the absolute pressure reached 10 -3 Pa, close valve A and then slowly open valve B. When the xylene in the xylene storage tank is reduced by about 3 mL by volatilization under vacuum, the adsorption amount of xylene is about 75 vol% of the water droplet pore volume of the porous material, and then close valve B.

[0060] The porous material that had absorbed xylene was placed in 10 mL of lanthanum chloride solution with a 5 wt% lanthanum oxide content, and was manually stirred and immersed for 20 minutes. It was then filtered and slowly dried in a nitrogen atmosphere. The temperature was set to rise from 60°C to 100°C after 60 minutes and then kept warm for 30 minutes to fully dry. Then the temperature was raised to 150°C after 30 minutes and kept warm for 30 minutes (the gas was promptly removed). Then the temperature was raised to 400°C for heat treatment for 30 minutes. A porous material C1 with lanthanum oxide loaded on the surface was obtained, and the lanthanum oxide loading was about 2 wt%. The La element electron probe micro-area analysis picture of C1 is shown in Figure 1 , and the element line scan distribution of a single particle section is shown in Figure 2 , it can be seen that the La-loaded metal is preferentially distributed on the outer surface of the catalyst. Along any radial direction of the particle, the ratio of the distance from the outer edge of the particle section to the position where the loaded element content reaches 80wt% of the total loading on the radius to the particle radius is recorded as the loading depth of the loaded element. Four different radii are selected from each particle for element line scan distribution statistics of the loading depth, and the average value is calculated and recorded as the loading depth of the particle. According to the above method, the data of the cross-section EPMA line scan of 5 different molecular sieve particles within the field of view are statistically analyzed, and the average value is calculated and recorded as the average loading depth of the porous material. The results are shown in Table 1. The particle size of lanthanum oxide particles was statistically analyzed by transmission electron microscopy. It can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there are very few cluster particles. The average particle size of the cluster particles is about 4nm.

[0061] Example 2

[0062] 40 parts by weight of pseudo-boehmite were acidified and then slurried to prepare acidified boehmite with a solid content of 12% by weight; and 60 parts by weight (on a dry basis) of type A molecular sieve were stirred for 0.5 hours, spray-dried and formed, and calcined at 550°C for 2 hours. The porous material A2 was obtained. The total pore volume of the porous material A2 was 0.51 mL / g, the pore volume of micropores and mesopores accounted for 90% of the total pore volume, and the proportion of macropores was 10%.

[0063] 10 g of porous material A2 (dry basis) was placed in a vacuum reactor for vacuum treatment. When the absolute pressure reached 10- 3 Pa, close valve A and then slowly open valve B. When the xylene in the xylene storage tank is reduced by about 3 mL by volatilization under vacuum, the adsorption amount of xylene is about 65 vol% of the water droplet pore volume of the porous material, and then close valve B.

[0064] The porous material after adsorption of xylene was placed in 10mL of 5wt% platinum chloride aqueous solution in terms of platinum oxide for manual stirring and impregnation for 20min, then filtered, and then slowly dried under a nitrogen atmosphere, set the temperature program to rise from 60°C to 100°C after 60min and keep warm for 30min to fully dry, then rise to 150°C and keep warm for 30min at 30min (the gas was promptly removed). Then heat it to 400°C for 30min. The porous material C2 with surface-loaded platinum oxide was obtained, and the loading amount of platinum oxide was about 2.5wt%. The characterization results are shown in Table 1. By counting the particle size of the platinum oxide particles by transmission electron microscopy, it can be seen that the particle size of the lanthanum oxide particles on the outer surface of the catalyst is mostly less than 2nm, and there is a very small amount of cluster particles, and the average particle size of the cluster particles is about 4nm.

[0065] Example 3

[0066] 20% Y-type molecular sieve (molar ratio of silicon oxide to aluminum oxide is 3) and 50% macroporous aluminum oxide and 30% aluminum oxide binder (the above materials are from the Changling Branch of the catalyst company) are fully ground and then subjected to ball rolling treatment to obtain small balls, which are dried at 110°C for 4 hours and then calcined at 550°C for 4 hours to obtain a small spherical porous material carrier A3. The total pore volume of the porous material A3 is 0.38 mL / g, the pore volume of micropores and mesopores accounts for 70% of the total pore volume, and the proportion of macropores is 30%.

[0067] 10 g of porous material A3 (dry basis) was placed in a vacuum reactor and vacuum treated. When the absolute pressure reached 10 -3 Pa, close valve A and then slowly open valve B. When the xylene in the xylene storage tank is reduced by about 3 mL by volatilization under vacuum, the adsorption amount of xylene is about 80 vol% of the water droplet pore volume of the porous material, and then close valve B.

[0068] The porous material after adsorption of xylene was placed in 10mL of 5wt% nickel nitrate aqueous solution in terms of nickel oxide and manually stirred for 20min, then filtered, and then slowly dried under a nitrogen atmosphere, and the program temperature was set to rise from 60°C to 100°C for 60min and kept warm for 30min to fully dry, and then heated to 150°C for 30min (the gas was promptly removed). Then the temperature was raised to 400°C for heat treatment for 30min. The porous material C3 with surface-loaded nickel oxide was obtained, and the loading amount of nickel oxide was about 1.8wt%. The characterization results are shown in Table 1. The particle size of the nickel oxide particles was counted by transmission electron microscopy, and it can be seen that the particle size of the lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there is a very small amount of cluster particles, and the average particle size of the cluster particles is about 3nm.

[0069] Example 4

[0070] The method of Example 1 is followed, except that in step (2), when the xylene in the xylene storage tank is reduced by about 0.8 mL by volatilization under vacuum, the adsorption amount of xylene is about 20 vol% of the water droplet pore volume of the porous material, and valve B is closed.

[0071] The porous material after adsorption of xylene was placed in 10mL of lanthanum chloride solution with 5wt% of lanthanum oxide and manually stirred for 20min, then filtered, and then slowly dried under a nitrogen atmosphere. The program temperature was set to rise from 60°C to 100°C for 60min and kept warm for 30min to fully dry, and then heated to 150°C for 30min (the gas was promptly removed). Then the temperature was raised to 400°C for heat treatment for 30min. The porous material C4 with surface-loaded lanthanum oxide was obtained, and the loading amount of lanthanum oxide was about 3.6wt%. The characterization results are shown in Table 1. The particle size of lanthanum oxide particles was counted by transmission electron microscopy. It can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there is a very small amount of cluster particles, and the average particle size of the cluster particles is about 6nm.

[0072] Example 5

[0073] The method of Example 1 is followed, except that in step (2), when the xylene in the xylene storage tank is reduced by about 3.7 mL by volatilization under vacuum, the adsorption amount of xylene is about 90 vol% of the water droplet pore volume of the porous material, and valve B is closed.

[0074] The porous material after adsorption of xylene was placed in 10mL of lanthanum chloride solution with 5wt% of lanthanum oxide and manually stirred for 20min, then filtered, and then slowly dried under a nitrogen atmosphere. The program temperature was set to rise from 60°C to 100°C for 60min and kept warm for 30min to fully dry, and then heated to 150°C for 30min (the gas was promptly removed). Then the temperature was raised to 400°C for heat treatment for 30min. The porous material C5 with surface-loaded lanthanum oxide was obtained, and the loading amount of lanthanum oxide was about 0.5wt%. The characterization results are shown in Table 1. The particle size of lanthanum oxide particles was counted by transmission electron microscopy. It can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there is a very small amount of cluster particles, and the average particle size of the cluster particles is about 9nm.

[0075] Example 6

[0076] The method of Example 1 is followed, except that step (2) does not involve vacuuming.

[0077] 3.0 mL of xylene was added dropwise into 10 g of the porous material A1 (dry basis) while being constantly stirred to obtain a porous material that adsorbs xylene.

[0078] The porous material after adsorption of xylene was placed in 10mL of lanthanum chloride solution with 5wt% of lanthanum oxide and manually stirred for 20min, then filtered, and then slowly dried under a nitrogen atmosphere. The program temperature was set to rise from 60°C to 100°C for 60min and kept warm for 30min to fully dry, and then heated to 150°C for 30min (the gas was promptly removed). Then the temperature was raised to 400°C and kept warm for 30min. The porous material C6 with surface-loaded lanthanum oxide was obtained, and the loading amount of lanthanum oxide was about 2.8wt%. The characterization results are shown in Table 1. The particle size of lanthanum oxide particles was counted by transmission electron microscopy. It can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there is a very small amount of cluster particles, and the average particle size of the cluster particles is about 8nm.

[0079] Example 7

[0080] According to the method of Example 1, the difference is that the drying conditions in step (2) include: setting the program temperature to rise from 60°C to 150°C after 120min and keep warm for 30min (the gas is promptly pumped away). Then the temperature is raised to 400°C and kept warm for 30min. The porous material C7 with lanthanum oxide loaded on the surface is obtained, and the loading amount of lanthanum oxide is about 2wt%. The characterization results are shown in Table 1. The particle size of lanthanum oxide particles is counted by transmission electron microscopy. It can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there are very few cluster particles, and the average particle size of the cluster particles is about 5nm.

[0081] Example 8

[0082] The method of Example 1 was followed, except that toluene was used instead of xylene. A porous material C7 with lanthanum oxide loaded on the surface was obtained, and the loading amount of lanthanum oxide was about 2.2wt%. The characterization results are shown in Table 1. The particle size of lanthanum oxide particles was counted by transmission electron microscopy, and it can be seen that the particle size of lanthanum oxide particles on the outer surface of the catalyst is mostly less than 1nm, and there are very few cluster particles, and the average particle size of the cluster particles is about 5nm.

[0083] Example 9

[0084] The method of Example 1 was followed, except that the porous material after adsorbing xylene was placed in 10 mL of 2 wt% lanthanum chloride solution based on lanthanum oxide, and then ammonia water was added dropwise under manual stirring to adjust the pH to 10, and then further stirred and filtered, and then slowly dried under a nitrogen atmosphere (set the temperature program to rise from 60°C to 100°C after 60 min and keep warm for 30 min to fully dry, and then rise to 150°C in 30 min and keep warm for 30 min (the gas was promptly removed). Then the temperature was raised to 400°C and kept warm for 30 min. A porous material C9 with lanthanum oxide loaded on the surface was obtained, and the loading amount of lanthanum oxide was about 2 wt%. Aggregated lanthanum oxide particles were observed by transmission electron microscopy, and the average particle size was about 300 nm.

[0085] Comparative Example 1

[0086] 10g of porous material A1 was placed directly in 10mL of 5% lanthanum chloride solution in terms of lanthanum oxide without organic treatment, and was manually stirred and immersed for 20min, then filtered, and then slowly dried under a nitrogen atmosphere. The program temperature was set to rise from 60°C to 100°C after 60min and kept warm for 30min to fully dry, and then the temperature was raised to 150°C and kept warm for 30min at 30min (the gas was promptly removed). Then the temperature was raised to 400°C for heat treatment for 30min. The porous material DC1 with surface-loaded lanthanum oxide was obtained, and the loading amount of lanthanum oxide was about 4.4wt%. The characterization results are shown in Table 1.

[0087] Comparative Example 2

[0088] 18 parts by weight of pseudo-boehmite was acidified and then pulped to prepare an acidified boehmite with a solid content of 12% by weight; then 10 parts by weight of aluminum sol (on a dry basis), about 3 parts of lanthanum chloride solution based on lanthanum oxide, 33 parts by weight of kaolin (on a dry basis) and 36 parts by weight of DASY.2.0 molecular sieve (on a dry basis) were added, stirred for 0.5 hours and then spray-dried, calcined at 550° C. for 2 hours, and washed twice with a 2% by weight ammonium chloride solution to obtain a porous material DC2 with lanthanum oxide loaded on the surface, and the loading amount of lanthanum oxide was about 3wt%. The characterization results are shown in Table 1.

[0089] Table 1

[0090]

[0091] From the results in Table 1, it can be seen that the surface loading method of the porous material provided by the present invention is to first adsorb organic matter on the porous material, adsorb the organic matter into the pores of the porous material, and then load the component to be loaded in a conventional manner, and then remove the organic matter by heat treatment or vacuum desorption. It can be seen from the comparison between Example 1 and Comparative Examples 1-2 that the method provided by the present invention can reduce the clogging of micropores or mesopores by the loaded components as much as possible, and can effectively control the loading depth of the porous material surface, thereby helping to improve the utilization rate of the loaded components.

[0092] In Example 6, the adsorption of organic matter was carried out under non-vacuum conditions. Compared with Example 1, the loading uniformity of the porous material after loading obtained in Example 6 was slightly worse, and the average loading depth was increased. This may be due to the poor adsorption uniformity of organic matter under non-vacuum conditions, which led to insufficient uniformity of the metal components.

[0093] 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 method for surface loading of porous materials, characterized in that: The method comprises: (1) contacting the porous material with the organic matter, and adsorbing the organic matter into the pores of the porous material; Wherein, the boiling point of the organic matter is 100-250°C; (2) introducing the component to be loaded onto the product obtained in step (1); (3) Removing organic matter from the product obtained in step (2).

2. The method according to claim 1, wherein: The boiling point of the organic matter is 110-200°C; Preferably, the organic matter is selected from substituted or unsubstituted aromatic hydrocarbons and / or alkanes, and optionally, at least one carbon atom in the aromatic hydrocarbons or alkanes is substituted by S, P or N; Preferably, the organic matter is selected from at least one of benzene, toluene, ethylbenzene, xylene, trimethylbenzene, trimethylphosphine, picoline and coltidine.

3. The method according to claim 1 or 2, wherein: Based on the water droplet pore volume of the porous material, the adsorption amount of the organic matter is 20-95 vol%, preferably 40-80 vol%.

4. The method according to any one of claims 1 to 3, wherein: The total pore volume of the porous material is 0.1-0.8 mL / g, preferably 0.2-0.6 mL / g; Preferably, in the porous material, the pore volume of micropores and mesopores accounts for 30-100% of the total pore volume, and the pore volume of macropores accounts for 0-70% of the total pore volume.

5. The method according to any one of claims 1 to 4, wherein: The porous material is selected from at least one of molecular sieves, porous inorganic oxides and porous clays; The molecular sieve is preferably at least one of pure silicon molecular sieve, silicon aluminum molecular sieve, silicon aluminum phosphorus molecular sieve, titanium silicon molecular sieve and silicon phosphorus molecular sieve; The porous inorganic oxide is preferably at least one of aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide and titanium oxide.

6. The method according to any one of claims 1 to 5, wherein: The contacting in step (1) is carried out under vacuum conditions. Preferably, the vacuum conditions include: an absolute pressure of 1×10 -5 Pa to 10Pa; Preferably, the contacting method in step (1) comprises: contacting an atmosphere containing organic matter with the porous material under vacuum conditions.

7. The method according to any one of claims 1 to 6, wherein: In step (2), the method of introducing the component to be loaded onto the product obtained in step (1) includes: impregnating or spraying a solution containing a precursor of the component to be loaded onto the product obtained in step (1), and then drying; Preferably, the boiling point of the solvent in the solution containing the component precursor to be loaded is lower than the boiling point of the organic matter; Preferably, at 25° C., the solubility of the solvent in the solution containing the component precursor to be loaded in 100 g of organic matter is not higher than 0.5 g; Preferably, the component to be loaded is a metal component and / or a non-metal component; Preferably, based on the mass of the porous material, the introduced amount of the component to be loaded is 0.01-6 wt % calculated as oxide.

8. The method according to claim 7, wherein: The drying temperature is 80-250°C and the drying time is 10-250min; Preferably, the drying includes a low-temperature drying stage and a high-temperature drying stage, wherein the temperature of the low-temperature drying stage is 80-110°C, the time is 1-100 min, and the heating rate is 1-20°C / min; the temperature of the high-temperature drying stage is 110-250°C, the time is 10-120 min, and the heating rate is 1-20°C / min; Preferably, the drying is performed under an inert atmosphere, which is preferably provided by nitrogen.

9. The method according to any one of claims 1 to 8, wherein: In step (3), the method of removing organic matter from the product obtained in step (2) is heat treatment or vacuum desorption; Preferably, the heat treatment conditions include: heat treatment temperature of 250-500°C and time of 10-180min; Preferably, the vacuum desorption conditions include: an absolute pressure of 1×10 -4 Pa to 1Pa, temperature is 20-30℃.

10. Use of the surface loading method of porous materials according to any one of claims 1 to 9 in catalyst preparation.

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