CN117654508A - Integral catalyst and preparation method thereof - Google Patents

Abstract

An integral catalyst and a preparation method thereof belong to the field of catalyst technology and overcome the defect in the prior art that the active components on the surface of the integral catalyst are more likely to fall off. The integrated catalyst provided by the present invention includes a catalytic part and a supporting part, the catalytic part is arranged on the surface of the supporting part, and the catalytic part and the supporting part are provided with an overlapping area. The integral catalyst of the present invention includes a catalytic part and a supporting part. By designing the supporting structure, the structural strength of the integral catalyst is improved. By arranging an overlapping area between the catalytic part and the supporting part, the binding force between the catalytic part and the supporting part is enhanced to prevent the active components from peeling off.

Description

Monolithic catalyst and preparation method thereof

Technical field

The invention belongs to the technical field of catalysts, and specifically relates to an integral catalyst and a preparation method thereof.

Background technique

Traditional granular catalysts have problems such as low porosity, large pressure drop in the catalyst bed, large temperature gradients at various points in the catalyst bed, and serious carbon deposition on the catalyst. In order to solve the above problems and further improve the reaction performance of the catalyst, researchers have proposed monolithic catalysts. Monolithic catalysts overcome the shortcomings of traditional granular catalysts. However, due to the manufacturing process, the specific surface area and strength of existing monolithic catalysts require For further improvement, the manufacturing process needs to be simplified.

Additive manufacturing technology does not require traditional tools, fixtures and multiple processing procedures. Parts of any complex shape can be quickly and accurately manufactured on one piece of equipment, thereby achieving "free manufacturing" of parts and solving the problem of many complex structural parts. Forming problem. Although there have been some studies on using additive manufacturing technology to prepare catalysts to prepare monolithic catalysts, the active ingredients are mostly combined with the matrix by impregnation, which has cumbersome processes, low binding force, short service life, and is not conducive to long-term high-pressure reactions. The problem.

The prior art CN112058317A discloses a method of 3D printing a monolithic catalyst. The designed three-dimensional model of the monolithic catalyst is sliced and then introduced into a screw extrusion 3D printer, and a catalytically active component slurry is used for the surface area layer of the monolithic catalyst. 3D printing, the internal skeleton area is 3D printed with ceramic slurry. In order to ensure that the surface area layer is adhered to the internal skeleton and prevent the surface active components from peeling off, the existing technology adds a large amount of binders, dispersants and other additives to the active component slurry, resulting in a reduction in the active ingredient content of the surface area layer. .

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the active components on the surface layer of the monolithic catalyst are more likely to fall off, thereby providing an monolithic catalyst and a preparation method thereof.

To this end, the present invention provides the following technical solutions.

In a first aspect, the present invention provides an integral catalyst, which includes a catalytic part and a supporting part. The catalytic part is disposed on the surface of the supporting part, and the catalytic part and the supporting part are provided with an overlapping area. The overlapping area refers to an area where the laser additive manufacturing process of the catalytic part and the laser additive manufacturing process of the supporting part are repeated.

Further, the catalytic part and the supporting part are both prepared through a laser additive manufacturing process.

Further, the thickness of the overlapping area is ≤ 20% of the cross-sectional diameter of the pillars of the support unit structure. The thickness of the overlapping area can be designed as needed. In order to ensure the strength of the supporting structure, the overlapping amount should not be higher than 20% of the cross-sectional diameter of the pillars of the supporting unit structure.

Further, the support part is formed by an array of support unit structures, and the support unit structure is a porous structure, preferably a lattice structure or a topology optimized structure.

Further, the catalytic part is coated on the surface of the supporting part, or

The catalytic part forms fins on the surface of the supporting part.

Further, the catalytic part is formed by an array of catalytic unit structures.

Furthermore, the catalytic unit structure and the supporting unit structure are arrayed in the same manner.

Further, the lattice structure is one of a body-centered cubic lattice structure, a face-centered cubic lattice structure, a tetrahedral lattice structure, a diamond-shaped lattice structure, and an arched truss lattice structure;

Optionally, the cross-sectional outer contour of the lattice structure pillars is polygonal or streamlined;

Optionally, the polygon is a square or a triangle;

Optionally, the streamline shape is circular.

Further, the catalytic part material includes at least one of nickel, copper, cobalt, iron, titanium, vanadium, cerium or zirconium;

and / or,

The support portion material includes at least one of nickel, copper, cobalt, iron, titanium, vanadium, cerium or zirconium.

The porosity of the catalytic part > the porosity of the supporting part _.

Furthermore, fins can be provided on the surface of the catalytic part to further increase the specific surface area of the catalyst.

Furthermore, the support part and the catalytic part are made of different powders, which can further reduce the cost of the precious metal catalyst.

Further, the catalytic part material also includes a binding material.

Furthermore, the catalytic part material and the supporting part material may respectively be pure metals of nickel, copper, cobalt, iron, titanium, vanadium, cerium or zirconium, or may be alloys including the above elements.

Further, the catalytic part material and/or the supporting part material is powder; preferably, the particle size of the powder is 10 to 500um.

In a second aspect, the present invention provides a method for preparing a monolithic catalyst, which includes the following steps:

Step 1. Design the models of the catalytic part and the supporting part respectively, and design the overlap between the catalytic part and the supporting part;

Step 2. Import the models of the catalytic part and the supporting part into the laser additive manufacturing equipment respectively, and adjust the model positions of the catalytic part and the supporting part according to the designed overlap amount;

Step 3: Set the laser additive manufacturing process parameters of the support part and the catalytic part respectively and prepare them to prepare a monolithic catalyst.

Further, in step 3, the laser scanning spacing for preparing the catalytic part is greater than the laser scanning spacing for preparing the supporting part;

and/or the laser scanning speed for preparing the catalytic part is greater than the laser scanning speed for preparing the supporting part.

Further, in step 2, after adjusting the model positions of the catalytic part and the supporting part according to the designed overlap amount, the models of the catalytic part and the supporting part are sliced separately;

Preferably, the slice thickness of the catalytic part is an integer multiple of the slice thickness of the supporting part, preferably 1 to 3 times.

Further, the laser additive manufacturing process is a selective laser melting process, a selective laser sintering process or a laser directed energy deposition process.

Further, the laser selective melting process includes:

The supporting part processing area and the catalytic part processing area are respectively scanned according to the set laser additive manufacturing process parameters of the supporting part and the catalytic part.

Preferably, when each layer is manufactured, when there is both a support part processing area and a catalytic part processing area, the support part processing area is scanned first, and then the catalytic part processing area is scanned. Scanning the support part first will help improve the overall mechanical properties and dimensional accuracy of the catalyst.

Optionally, the supporting part and the catalytic part are made of the same material.

Further, the laser directional energy deposition includes:

Load the materials of the support part and the catalytic part into different powder bins of the coaxial powder feeding additive manufacturing equipment respectively. According to the set laser additive manufacturing process parameters of the support part and the catalytic part, the support part processing area and the catalytic part processing area are respectively Carry out powder feeding and laser scanning;

Optionally, the supporting part and the catalytic part are made of the same or different materials.

When using powder-feed additive manufacturing technology to manufacture catalysts, after completing the modeling of the support part and the catalytic part respectively, they are imported into the powder-laying additive manufacturing equipment, and their positions are adjusted according to the designed overlap amount. In order to ensure the strength of the supporting part and improve the porosity of the catalytic part, different powder feeding speeds can be used for the supporting part and the catalytic part. Preferably, during the manufacturing process, the powder feeding rate of the supporting part is greater than the powder feeding rate of the catalytic part.

The laser directional energy deposition process can be powder feeding or wire feeding.

The support part is the guarantee of the strength of the catalyst. Therefore, the manufacturing process parameters of the support part processing area adopt the optimal parameters recommended by the machine to create a support structure with high density. The machine recommended optimal parameters refer to the recommended optimal process parameters built into the additive manufacturing equipment for different materials. The catalytic part is the active part of the catalyst. The processing area of the catalytic part adjusts process parameters by increasing the laser scanning speed and scanning spacing to create a catalytic structure with low density and rich in voids and cracks.

The technical solution of the present invention has the following advantages:

1. The integrated catalyst provided by the present invention includes a catalytic part and a supporting part, the catalytic part is arranged on the surface of the supporting part, and the catalytic part and the supporting part are provided with an overlapping area.

The integral catalyst of the present invention includes a catalytic part and a supporting part. By designing the supporting structure, the structural strength of the integral catalyst is improved. By arranging an overlapping area between the catalytic part and the supporting part, the binding force between the catalytic part and the supporting part is enhanced to prevent the active components from peeling off.

2. In the monolithic catalyst provided by the present invention, the porosity of the catalytic part is greater than the porosity of the supporting part. While ensuring the structural strength of the catalyst, the density of the outer surface of the catalyst is reduced and the specific surface area of the catalyst is increased.

3. The preparation method of the integrated catalyst of the present invention includes the following steps: Step 1. Design the models of the catalytic part and the supporting part respectively, and design the overlap amount of the catalytic part and the supporting part; Step 2. Combine the models of the catalytic part and the supporting part. Import laser additive manufacturing equipment respectively, and adjust the model positions of the catalytic part and the supporting part according to the designed overlap amount; Step 3. Set the laser additive manufacturing process parameters of the supporting part and the catalytic part respectively and prepare them to obtain an integral model. catalyst.

Designing the models of the catalytic part and the supporting part separately, and designing the overlap amount of the catalytic part and the supporting part can improve the bonding force between the catalytic part and the supporting part.

The manufacturing method proposed by the present invention has a simple process flow, and the catalyst completed by additive manufacturing can be used directly without other processing steps.

4. The slice thickness of the catalytic part is an integer multiple of the slice thickness of the supporting part, preferably 1 to 3 times. The porosity of the catalytic part is made greater than the porosity of the supporting part, which not only ensures the structural strength of the catalyst, but also reduces the density of the outer surface of the catalyst and increases the specific surface area of the catalyst.

The present invention adopts a partitioned manufacturing method and adopts different process parameters in different areas of the model to ensure the structural strength of the catalyst while reducing the density of the outer surface of the catalyst and increasing the specific surface area of the catalyst.

This invention gives full play to the advantages of "free manufacturing" of additive manufacturing technology, and realizes the direct molding of the catalyst through split modeling and partitioned manufacturing methods. While ensuring the strength of the catalyst, it further increases the specific surface area and activity of the catalyst. Ingredient content.

5. The present invention further reduces the cost of the precious metal catalyst by adopting the integrated manufacturing method of multiple materials.

Description of drawings

In order to more clearly explain the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings illustrate some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting any creative effort.

Figure 1 is a flow chart for the preparation of the monolithic catalyst of the present invention;

Figure 2 is a schematic diagram of the model of the support part and the catalytic part and their coordination;

Figure 3 is an enlarged schematic diagram of the support part and the catalytic part after they are matched;

Figure 4 is a cross-sectional view along line A-A of Figure 3;

Figure 5 Slice and enlarged schematic diagram.

Reference signs:

1-support part; 2-catalytic part; 3-support unit structure; 4-catalytic unit structure; 5-overlapping area.

Detailed ways

The following examples are provided to better understand the present invention. They are not limited to the best embodiments and do not limit the content and protection scope of the present invention. Anyone who is inspired by the present invention or uses the present invention to Any product that is identical or similar to the present invention by combining it with other features of the prior art falls within the protection scope of the present invention.

If no specific experimental steps or conditions are specified in the examples, the procedures can be carried out according to the conventional experimental steps or conditions described in literature in the field. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional reagent products that can be purchased commercially.

Example 1

This embodiment provides a method for preparing a monolithic catalyst, as shown in Figure 1, including the following steps:

1. Use 3D model design software to model the support unit structure 3 and the catalytic unit structure 4 respectively. During the modeling process, design the overlap between the support part 1 and the catalytic part 2 as needed, and design the support unit structure 3 and catalytic part 2 according to the required catalyst size. The catalytic unit structures 4 are arrayed separately to obtain models of the support part and the catalytic part, as shown in Figure 2.

In this embodiment, the cross section of the support unit structure 3 pillar is shown in Figure 4, which is a circle with a diameter of 1 mm. The catalytic part 2 is coated on the surface of the supporting part 1; the cross-section of the pillar of the catalytic unit structure 4 is shown in Figure 4, which is a ring with an inner diameter of 0.8mm and an outer diameter of 1.3mm, with a thickness of 5 in the overlapping area (that is, the overlapping area is along the cross-section diameter of the supporting unit structure The total thickness in the direction) is 20% of the cross-sectional diameter of the support unit structure pillar, that is, the overlap of the support part 1 and the catalytic part 2 is 0.2mm. In this embodiment, the support unit structure 3 and the catalytic unit structure 4 are both body-centered cubic lattice structures.

2. Introduce the models of the catalytic part 2 and the supporting part 1 into the laser selective melting equipment respectively, adjust their positions according to the designed overlap amount, and then slice the model after adjustment, as shown in Figures 2, 3, and 5. The slice thickness of the supporting part 1 is 0.02mm, and the slice thickness of the catalytic part 2 is 0.04mm.

3. Select nickel-based alloy GH4169 powder as the material of the catalyst. The catalytic part and the supporting part are made of the same material. Dry the GH4169 powder and put it into the powder bin of the laser selective melting additive manufacturing equipment.

4. The process parameters of the support part are: laser power 150W, scanning speed 400mm/s, scanning spacing 0.09mm, slice thickness 0.02mm; the process parameters of the catalytic part are: laser power 120W, scanning speed 600mm/s, scanning spacing 0.12mm, The slice thickness is 0.04mm.

5. Use the brush as the powder spreading mechanism, adjust the position of the substrate, and set the substrate to preheat.

6. Open the protective gas valve to discharge the air in the molding chamber. When the oxygen content is lower than the set value, start manufacturing according to the set process parameters.

During the processing, spread 0.02mm of powder, then scan the support part processing area (A+B), spread 0.02mm powder again, scan the support part processing area, and then scan the catalytic part processing area (B+C) . Repeat the above steps.

7. After fabrication is completed, wire cutting is used to separate the catalyst from the substrate.

The separated catalyst can be used directly.

According to GB/T228.1-2010 "Tensile Test of Metal Materials Part 1: Room Temperature Test Method", the bonding force of the support part and the catalytic part in Example 1 was tested, and the bonding force reached 1000MPa.

Example 2

This embodiment provides a method for preparing a monolithic catalyst, which includes the following steps:

1. Use 3D model design software to model the support unit structure 3 and the catalytic unit structure 4 respectively. During the modeling process, design the overlap between the support part 1 and the catalytic part 2 as needed, and design the support unit structure 3 and catalytic part 2 according to the required catalyst size. The catalytic unit structures 4 are arrayed separately to obtain models of the support part and the catalytic part, as shown in Figure 2.

In this embodiment, the cross section of the support unit structure 3 pillar is shown in Figure 4, which is a circle with a diameter of 3 mm. The catalytic part 2 is covered on the surface of the supporting part 1. The cross-section of the pillar of the catalytic unit structure 4 is shown in Figure 4, which is a ring with an inner diameter of 2.7mm and an outer diameter of 3.3mm. That is, the overlapping area of the supporting part and the catalytic part overlaps 10% of the cross-sectional diameter of the supporting unit structure. In this embodiment, the support unit structure 3 and the catalytic unit structure 4 are both body-centered cubic lattice structures.

2. Introduce the models of the catalytic part 2 and the supporting part 1 into the laser directional energy deposition equipment respectively, and adjust their positions according to the designed overlap amount.

3. Select 316L metal powder as the supporting material, dry the 316L metal powder and load it into the powder bin of the coaxial powder feeding additive manufacturing equipment. Platinum metal powder is selected as the catalytic part material. The platinum metal powder is dried and loaded into another powder bin of the coaxial powder feeding additive manufacturing equipment.

4. The process parameters of the support part are: laser power 800W, scanning speed 5mm/s, powder feeding rate 16g/min, overlap rate 0.4mm; the process parameters of the catalytic part are: laser power 2000W, scanning speed 10mm/s, feeding rate The powder rate is 1g/min, and the overlap rate is 0.2mm.

5. Adjust the position of the substrate and set the substrate preheating.

6. Open the protective gas valve and start manufacturing according to the set process parameters.

7. After fabrication is completed, wire cutting is used to separate the catalyst from the substrate.

The separated catalyst can be used directly.

The integral catalyst provided by the present invention has a high binding force between the catalytic part and the supporting part, thereby preventing the active components from peeling off. The porosity of the catalytic part > the porosity of the supporting part not only ensures the structural strength of the catalyst, but also reduces the density of the outer surface of the catalyst and increases the specific surface area of the catalyst.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (15)

1. An integral catalyst, characterized in that it includes a catalytic part and a supporting part, the catalytic part is arranged on the surface of the supporting part, and the catalytic part and the supporting part are provided with an overlapping area. 2. The monolithic catalyst according to claim 1, wherein the catalytic part and the supporting part are both prepared by a laser additive manufacturing process. 3. The monolithic catalyst according to claim 1, characterized in that the support part is formed by an array of support unit structures, and the support unit structure is a porous structure, preferably a lattice structure or a topology optimized structure. 4. The monolithic catalyst according to claim 3, characterized in that the thickness of the overlapping area is ≤ 20% of the cross-sectional diameter of the supporting unit structural pillars. 5. The monolithic catalyst according to any one of claims 1 to 4, characterized in that the catalytic part is coated on the surface of the supporting part, or The catalytic part forms fins on the surface of the supporting part. 6. The monolithic catalyst according to claim 3, wherein the catalytic part is formed by an array of catalytic unit structures. 7. The monolithic catalyst according to claim 6, wherein the catalytic unit structure and the supporting unit structure are arranged in the same array manner. 8. The monolithic catalyst according to claim 3, wherein the lattice structure is a body-centered cubic lattice structure, a face-centered cubic lattice structure, a tetrahedral lattice structure, a diamond-type lattice structure, or an arched lattice structure. One of the truss lattice structures; Optionally, the cross-sectional outer contour of the lattice structure pillars is polygonal or streamlined; Optionally, the polygon is a square or a triangle; Optionally, the streamline shape is circular. 9. The monolithic catalyst according to any one of claims 1 to 4, characterized in that the catalytic part material includes at least one of nickel, copper, cobalt, iron, titanium, vanadium, cerium or zirconium; and / or, The support portion material includes at least one of nickel, copper, cobalt, iron, titanium, vanadium, cerium or zirconium. 10. A method for preparing a monolithic catalyst, which is characterized by comprising the following steps: Step 1. Design the models of the catalytic part and the supporting part respectively, and design the overlap between the catalytic part and the supporting part; Step 2. Import the models of the catalytic part and the supporting part into the laser additive manufacturing equipment respectively, and adjust the model positions of the catalytic part and the supporting part according to the designed overlap amount; Step 3: Set the laser additive manufacturing process parameters of the support part and the catalytic part respectively and prepare them to prepare a monolithic catalyst. 11. The method for preparing an integral catalyst according to claim 10, wherein in step 3, the laser scanning distance for preparing the catalytic part is greater than the laser scanning distance for preparing the supporting part; and/or the laser scanning speed for preparing the catalytic part is greater than the laser scanning speed for preparing the supporting part. 12. The preparation method of the integral catalyst according to claim 10, characterized in that, in step 2, after adjusting the model positions of the catalytic part and the supporting part according to the designed overlap amount, the models of the catalytic part and the supporting part are adjusted. Perform slicing processing separately; Preferably, the slice thickness of the catalytic part is an integer multiple of the slice thickness of the supporting part, preferably 1 to 3 times. 13. The preparation method of the monolithic catalyst according to any one of claims 10 to 12, characterized in that the laser additive manufacturing process is a laser selective melting process, a laser selective sintering process or a laser directional energy deposition. 14. The preparation method of monolithic catalyst according to claim 13, characterized in that the laser selective melting process includes: Scan the support part processing area and the catalytic part processing area respectively according to the set laser additive manufacturing process parameters of the support part and catalytic part; Optionally, the supporting part and the catalytic part are made of the same material. 15. The preparation method of monolithic catalyst according to claim 13, characterized in that the laser directed energy deposition includes: Load the materials of the support part and the catalytic part into different powder bins of the coaxial powder feeding additive manufacturing equipment respectively. According to the set laser additive manufacturing process parameters of the support part and the catalytic part, the support part processing area and the catalytic part processing area are respectively Carry out powder feeding and laser scanning; Optionally, the supporting part and the catalytic part are made of the same or different materials.