CN114618323A - Porous substrate structure and method of making the same - Google Patents

Abstract

The present invention provides a porous substrate structure and a manufacturing method thereof. The porous substrate structure includes a substrate, an anodized aluminum oxide layer, and a bimetallic oxide layer. The substrate has a plurality of holes. The anodic aluminum oxide layer is disposed on the substrate. The double metal oxide layer is disposed on the anodic aluminum oxide layer.

Description

Porous substrate structure and method of making the same

technical field

The present invention relates to a porous substrate structure and a manufacturing method thereof.

Background technique

Due to the particularity of palladium membranes in hydrogen transmission, palladium membranes are currently mostly formed on the surface of porous substrates for hydrogen filtration treatment. By dissociating hydrogen molecules on the surface of the palladium membrane and penetrating the membrane layer, hydrogen molecules can be separated from other gas molecules. In general, the thickness of the palladium membrane is used as an indicator of the hydrogen filtration performance. That is to say, in order to increase the hydrogen permeability of the palladium film, the thickness of the palladium film must be reduced, and the defects of the film layer must be reduced as much as possible to improve the density of the palladium film.

In addition, by modifying the surface of the porous substrate (eg, forming a modified layer), the thickness of the palladium film with the desired density can be reduced. However, if the thickness of the modified layer on the porous substrate is too large, the problem of insufficient adhesion of the modified layer and peeling from the porous substrate may occur.

SUMMARY OF THE INVENTION

The present invention is directed to a porous substrate structure, wherein an anodized aluminum oxide layer is arranged between the substrate and the modification layer (double metal oxide layer).

The present invention is directed to a method for manufacturing a porous substrate structure, wherein an anodic aluminum oxide layer is formed between the substrate and a modification layer (a double metal oxide layer).

According to an embodiment of the present invention, the porous substrate structure includes a substrate, an anodized aluminum oxide layer, and a bimetallic oxide layer. The substrate has a plurality of holes. The anodic aluminum oxide layer is disposed on the substrate. The double metal oxide layer is disposed on the anodized aluminum oxide layer.

According to an embodiment of the present invention, the manufacturing method of the porous substrate structure includes the following steps. An anodized aluminum oxide layer is formed on a substrate, wherein the substrate has a plurality of pores. A bimetallic oxide layer is formed on the anodic aluminum oxide layer.

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

Description of drawings

1A to 1D are schematic cross-sectional views of the manufacturing process of the porous substrate structure according to the embodiment of the present invention;

2A is a cross-sectional image of a porous substrate structure in which a double metal oxide layer is directly formed on the substrate;

FIG. 2B is a cross-sectional image view of the porous substrate structure according to the embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, structure principle and working principle of the present invention are described in detail:

The terms "including", "including", "having" and the like mentioned in the text are all open-ended terms, that is, "including but not limited to".

Also, herein, a range represented by "one value to another value" is a general representation that avoids listing all the values in the range in the specification. Thus, the recitation of a particular numerical range includes any number within that numerical range as well as any smaller numerical range bounded by any number within that numerical range.

In addition, the directional terms such as "upper" and "lower" mentioned in the text are only used to refer to the direction of the drawings, and are not used to limit the present invention.

1A to 1D are schematic cross-sectional views of the manufacturing process of the porous substrate structure according to the embodiment of the present invention. The porous substrate structures of embodiments of the present invention allow gas penetration for applications in gas treatment (eg, hydrogen filtration treatment) such as separation of gases and the like.

First, referring to FIG. 1A , a substrate 100 is provided. In this embodiment, the material of the base material 100 is porous stainless steel, but the present invention is not limited thereto. In other embodiments, the material of the substrate 100 may be porous ceramics. The substrate 100 has a plurality of holes 100a for gas to penetrate. The diameter of the hole 100a is, for example, between 1 μm and 30 μm. The substrate 100 may be a tubular substrate or a sheet substrate, which is not limited in the present invention.

Then, according to actual requirements, filling particles 102 may be filled in the holes 100a. In this way, when the pore size of the holes 100a is relatively large, filling the filling particles 102 in the holes 100a can reduce the pore size of the holes 100a, which can prevent the film layer formed on the substrate 100 from sinking into the holes 100a, resulting in film formation. The surface of the layer is uneven or the hole 100a is blocked. In addition, filling the filling particles 102 in the holes 100a can improve the problem of uneven pore size of the holes 100a.

The material of the filling particles 102 is, for example, aluminum oxide, silicon oxide, calcium oxide, cerium oxide, titanium oxide, chromium oxide, manganese oxide, iron oxide, nickel oxide, copper oxide, zinc oxide, zirconium oxide, or a combination thereof. On the premise that the filling particles 102 will not fill up the holes 100a, the present invention does not limit the particle size of the filling particles 102.

In addition, when the pore size of the holes 100a is relatively small, since the film layer formed on the substrate 100 is not easily trapped in the holes 100a, the filling particles 102 do not need to be filled in the holes 100a.

Next, referring to FIG. 1B , an aluminum layer 104 is formed on the substrate 100 . The thickness of the aluminum layer 104 is, for example, not more than 3 μm. The formation method of the aluminum layer 104 is, for example, vacuum evaporation or electroless plating.

Then, referring to FIG. 1C , the aluminum layer 104 is anodized to form an anodized aluminum oxide (anodic aluminum oxide, AAO) layer 106 . After the anodic treatment, the formed anodic aluminum oxide layer 106 has a plurality of holes 106a penetrating the anodic aluminum oxide layer 106, and the holes 106a expose the substrate 100 and the holes 100a. for gas penetration. In the embodiment of the present invention, since the thickness of the aluminum layer 104 is not more than 3 μm, for example, after the anodized aluminum layer 106 is formed by anodizing, the holes 106 a can penetrate the anodized aluminum layer 106 . When the thickness of the aluminum layer 104 exceeds 3 μm, the formed holes 106 a cannot penetrate the anodized aluminum layer 106 . As such, the gas will not be able to penetrate the anodized aluminum layer 106 and the substrate 100 .

Furthermore, after anodizing, the aluminum layer 104 is transformed into an anodized aluminum layer 106 with a flat surface and high porosity. Therefore, the anodized aluminum oxide layer 106 can be used as a modification layer of the substrate 100 to improve the flatness of the subsequent film layers formed thereon. In this embodiment, when the hole diameter of the hole 100a is relatively large, the aluminum layer 104 can be prevented from sinking into the hole 100a because the filling particles 102 are filled in the hole 100a. Therefore, the aluminum layer 104 can have a flat surface without causing The hole 100a is blocked. In this way, the formed anodic aluminum oxide layer 106 can have higher surface flatness, and the gas can effectively penetrate the anodic aluminum oxide layer 106 and the substrate 100 .

Next, referring to FIG. 1D , a double metal oxide layer 108 is formed on the anodic aluminum oxide layer 106 to form the porous substrate structure 10 according to the embodiment of the present invention. There are holes 108a in the bimetal oxide layer 108 for gas to penetrate. In the embodiment of the present invention, the material of the double metal oxide layer 108 is, for example, double metal oxide. In one embodiment, the bimetallic oxide may be, for example, lithium aluminum oxide. Additionally, in some embodiments, the bimetallic oxide may be a layered bimetallic oxide, which may be represented by Equation 1,

[M ^II _1-x M ^III _x ]O _y formula 1

Wherein M ^II is Mg ²⁺ , Zn ²⁺ , Fe ²⁺ , Ni ²⁺ , Co ²⁺ , Cu ²⁺ or Li ⁺ , M ^III is Al ³⁺ , Cr ³⁺ , Fe ³⁺ or Sc ³⁺ , x is between 0.2 and 0.33 and y is between 0.7 and 2. In addition, in the embodiment of the present invention, the method for forming the double metal oxide layer 108 is, for example, prior to forming a double metal hydroxide (layered double hydroxide, LDH) layer (not shown) on the anodic aluminum oxide layer 106 . Then, the double metal hydroxide layer is calcined to obtain a double metal oxide layer. The method of forming the double metal hydroxide layer on the anodic aluminum oxide layer 106 may be, for example, but not limited to, electroless plating, hot dipping, physical evaporation, chemical evaporation, co-deposition method or hydrothermal method. Bimetallic hydroxides are precursors to bimetallic oxides that can be converted to bimetallic oxides via high temperature treatment (eg, calcination). In addition, the temperature of the calcination treatment is about 300°C to 500°C.

In an embodiment of the present invention, the thickness of the double metal oxide layer 108 is less than 3 μm. In detail, since the anodized aluminum oxide layer 106 is formed on the substrate 100 , a thinner bimetallic oxide layer can be used to achieve the modification effect, thereby improving the adhesion of the bimetallic oxide layer 108 on the substrate 100 . In this way, the thickness of the double metal oxide layer 108 can be reduced to less than 3 μm, so as to avoid the problem of insufficient adhesion due to excessive thickness in order to improve the surface flatness, thereby leading to the peeling off of the double metal oxide layer 108 . When the thickness of the bimetallic oxide layer is reduced, the gas throughput can also be increased.

In addition, since the anodized aluminum oxide layer 106 has a flat surface, the bimetallic oxide layer 108 formed on the anodized aluminum oxide layer 106 can also have a flat surface. In this way, the double metal oxide layer 108 can be used as a modification layer of the substrate 100 , so that the subsequently formed film layer has fewer defects and higher density.

In an embodiment of the present invention, the porous substrate structure 10 includes a substrate 100 having pores 100a, an anodized aluminum oxide layer 106 having pores 106a, and a bimetal oxide layer 108 having pores 108a. Accordingly, the porous substrate structure 10 may allow gas penetration for applications in gas treatment (eg, hydrogen filtration treatment) such as separation of gases. The structure and gas permeation characteristics of the porous substrate structure 10 will be further described below.

Example:

The pores on the surface of the porous stainless steel pipe (PSS, Pall Accusep filter, P/N: 7CC6L465236235SC02) were filled with alumina particles, wherein the average particle size of the alumina particles was 10 μm. Next, the stainless steel pipe filled with alumina particles was placed in a vacuum evaporation machine for surface evaporation. Place 1g aluminum ingot on the target table in the chamber, pump the chamber pressure to below 1×10 ^-4 torr with a vacuum pump, start to rotate the stainless steel pipe to be evaporated and heat the target table to make the surface extremely thin (less than 3μm) ) of the aluminum layer. Next, anodize the stainless steel pipe plated with the aluminum layer to obtain a stainless steel pipe coated with an anodized aluminum layer on the surface.

The AlLi intermetallic compound (based on the total weight of the AlLi intermetallic compound, the Li content is about 18 wt.% to 21 wt.%) powder is placed in 1000 mL of pure water, and nitrogen is introduced and aerated and stirred to make most of the AlLi The intermetallic compound powder reacts with water and dissolves. Next, the impurities were filtered to obtain a clear alkaline solution containing Li ⁺ and Al ³⁺ (pH about 11.0 to 12.3).

The stainless steel pipe coated with anodized aluminum layer was immersed in an alkaline solution containing Li ⁺ and Al ^{3 +} for about 2 hours and then dried, so that the continuous phase layered aluminum hydroxide layer containing lithium was coated on the anodized aluminum layer. Next, the stainless steel pipe was calcined at 500° C. for two hours to form a layered lithium-aluminum oxide layer on the anodic aluminum oxide layer, wherein the thickness of the lithium-aluminum oxide layer was about 2.9 μm, to obtain the porous substrate of this example. material structure.

Comparative example:

A porous substrate structure was formed in the same manner as in the Example except that the anodic aluminum oxide layer was not formed, wherein the thickness of the lithium aluminum oxide layer was about 6.4 μm.

FIG. 2A is a cross-sectional image of a porous substrate structure of a comparative example. FIG. 2B is a cross-sectional image of a porous substrate structure according to an embodiment of the present invention. It can be clearly seen from FIG. 2A and FIG. 2B that when an anodized aluminum oxide layer is arranged between the double metal oxide layer and the substrate, the double metal oxide layer can meet the required flatness (the maximum drop on the surface is 2.8). μm) has a thinner thickness, and thus can effectively prevent the modification layer (double metal oxide layer) from peeling off the substrate.

In addition, the porous substrate structure of the embodiment of the present invention and the porous substrate structure of the comparative example (the metal oxide layer is directly formed on the substrate) were tested for gas permeability, and the results are shown in Table 1.

Gas Penetration Test:

The porous substrate structure to be measured is placed in the test chamber, then nitrogen gas is passed into the test chamber, and the pressure value is monitored by a pressure gauge. A flow meter was used to measure the nitrogen flow from the open end of the test chamber and to calculate the nitrogen flux at a specific pressure.

Nitrogen flux (m³/m²-hr-atm) Example 107 Comparative example 85

Table 1

It can be clearly seen from FIG. 2A, FIG. 2B and Table 1 that in the embodiment of the present invention, since an anodized aluminum oxide layer is arranged between the porous substrate and the modification layer (double metal oxide layer), the modification layer (double metal oxide layer) is The metal oxide layer) can have a thinner thickness under the condition of the same flatness, and at the same time have a higher gas flux, that is, the porous substrate structure of the embodiment of the present invention can have a higher gas permeability .

Of course, the present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding Changes and deformations should belong to the protection scope of the appended claims of the present invention.

Claims (18)

1. a porous substrate structure, is characterized in that, comprises: substrate, with a plurality of holes; an anodized aluminum layer disposed on the substrate; and A double metal oxide layer is disposed on the anodic aluminum oxide layer. 2 . The porous substrate structure according to claim 1 , wherein the thickness of the double metal oxide layer is less than 3 μm. 3 . 3. The porous substrate structure of claim 1, wherein the bimetallic oxide layer comprises a layered bimetallic oxide. 4. The porous substrate structure according to claim 3, wherein the layered bimetallic oxide is represented by formula 1, [M ^II _1-x M ^III _x ]O _y formula 1 Wherein M ^II is Mg ²⁺ , Zn ²⁺ , Fe ²⁺ , Ni ²⁺ , Co ²⁺ , Cu ²⁺ or Li ⁺ , M ^III is Al ³⁺ , Cr ³⁺ , Fe ³⁺ or Sc ³⁺ , x is between 0.2 and 0.33 and y is between 0.7 and 2. 5 . The porous substrate structure according to claim 1 , wherein the thickness of the anodic aluminum oxide layer is not more than 3 μm. 6 . 6 . The porous substrate structure according to claim 1 , further comprising filling particles arranged in the plurality of holes, and the material of the filling particles comprises aluminum oxide, silicon oxide, calcium oxide, and cerium oxide. 7 . , titanium oxide, chromium oxide, manganese oxide, iron oxide, nickel oxide, copper oxide, zinc oxide, zirconium oxide, or a combination of the above. 7. The porous substrate structure according to claim 1, wherein the material of the substrate comprises stainless steel or ceramics. 8. A method for manufacturing a porous substrate structure, comprising: forming an anodized aluminum oxide layer on a substrate, wherein the substrate has a plurality of pores; and A bimetallic oxide layer is formed on the anodic aluminum oxide layer. 9 . The method for manufacturing a porous substrate structure according to claim 8 , wherein the thickness of the double metal oxide layer is less than 3 μm. 10 . 10. The method for manufacturing a porous substrate structure according to claim 8, wherein the method for forming the double metal oxide layer comprises: forming a double metal hydroxide layer on the anodic aluminum oxide layer; and The double metal hydroxide layer is calcined. 11 . The method for manufacturing a porous substrate structure according to claim 10 , wherein the method for forming the double metal hydroxide layer comprises chemical plating, hot dipping, physical evaporation, chemical evaporation, and co-precipitation. 12 . method or hydrothermal method. 12 . The method for manufacturing a porous substrate structure according to claim 10 , wherein the double metal hydroxide layer comprises a layered double metal hydroxide. 13 . 13. The method for producing a porous substrate structure according to claim 12, wherein the layered bimetallic oxide is represented by Formula 1, [M ^II _1-x M ^III _x ]O _y formula 1 Wherein M ^II is Mg ²⁺ , Zn ²⁺ , Fe ²⁺ , Ni ²⁺ , Co ²⁺ , Cu ²⁺ or Li ⁺ , M ^III is Al ³⁺ , Cr ³⁺ , Fe ³⁺ or Sc ³⁺ , x is between 0.2 and 0.33 and y is between 0.7 and 2. 14 . The method for manufacturing a porous substrate structure according to claim 8 , wherein the thickness of the anodized aluminum oxide layer is not more than 3 μm. 15 . 15. The method for manufacturing a porous substrate structure according to claim 8, wherein the method for forming the anodic aluminum oxide layer comprises: forming an aluminum layer on the substrate; and The aluminum layer is anodized. 16 . The method for manufacturing a porous substrate structure according to claim 15 , wherein the method for forming the aluminum layer on the substrate comprises vacuum evaporation or electroless plating. 17 . 17 . The method for manufacturing a porous substrate structure according to claim 15 , wherein before forming the aluminum layer, the method further comprises filling the plurality of holes with filler particles. 18 . 18. The method for manufacturing a porous substrate structure according to claim 8, wherein the material of the substrate comprises stainless steel or ceramics.

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