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CN-121992334-A - Method for efficiently preparing high-performance high-stability hydrogen production electrode

CN121992334ACN 121992334 ACN121992334 ACN 121992334ACN-121992334-A

Abstract

The invention discloses a method for efficiently preparing a high-performance high-stability hydrogen production electrode and the electrode obtained by the method, and belongs to the technical field of electrode material preparation. The method adopts at least two plasma spray guns arranged front and back to carry out one-time continuous multilayer gradient spraying on a nickel screen matrix, wherein the spray gun at the front end uses high-nickel low-aluminum Raney nickel powder to spray a bottom layer to ensure high binding force with the matrix, the spray gun at the rear end uses low-nickel high-aluminum (binary or multi-element) Raney nickel powder to spray a surface layer, and a porous high-activity catalytic layer is formed after alkali liquor activation. A spray gun can be additionally arranged in the middle to spray a transition layer. The invention constructs the gradient structure of the strong bonding bottom layer-high activity surface layer by one-time spraying, thereby fundamentally solving the contradiction that the bonding force and the catalytic activity of the traditional single-layer spraying electrode are difficult to be compatible, and greatly improving the production efficiency. The obtained electrode has excellent electrocatalytic activity, structural stability and long service life, and is suitable for hydrogen production by alkaline water electrolysis.

Inventors

  • WANG CHAO
  • ZHANG WENYONG
  • XIA WEI
  • SHEN RONGAN

Assignees

  • 江苏奇纳氢能科技有限公司

Dates

Publication Date
20260508
Application Date
20260204

Claims (8)

  1. 1. The method for efficiently preparing the high-performance high-stability hydrogen production electrode is characterized by comprising the following steps of: Spraying a Raney nickel catalyst coating on a nickel screen substrate by adopting a multi-spray gun plasma spraying system, wherein the multi-spray gun plasma spraying system is provided with at least two plasma spray guns which are arranged front and back along the spraying direction; the spraying process is multilayer gradient spraying, and specifically comprises the following steps: Spraying a first layer of catalyst coating to the nickel screen matrix by using a plasma spray gun at the forefront end, wherein spraying powder used for the first layer of catalyst coating is high-nickel low-aluminum Raney nickel alloy powder, and the mass ratio of nickel to aluminum is (85-95) (15-5); Spraying an outermost catalyst coating on the surface of the first catalyst coating by using a plasma spray gun at the rearmost end, wherein spraying powder used for the outermost catalyst coating is low-nickel high-aluminum Raney nickel alloy powder, and the mass ratio of nickel to aluminum is (40-75) (60-25); The multi-layer gradient spraying is completed in one continuous spraying process; And after the spraying is finished, alkali liquor activation treatment is carried out on the electrode network with the gradient coating, and the aluminum component in the coating is dissolved out to obtain the hydrogen production electrode.
  2. 2. A method for efficiently producing a high performance high stability hydrogen-producing electrode as described in claim 1 wherein said multi-gun plasma spray system is provided with three or more plasma guns arranged one after the other in the spray direction, at least one intermediate transition layer catalyst coating is sprayed between said first layer and said outermost layer using at least one intermediate plasma gun positioned in the middle, the mass ratio of nickel to aluminum in the spray powder used for said intermediate transition layer being between the mass ratio of nickel to aluminum in said first layer and said outermost layer.
  3. 3. The method for efficiently preparing the high-performance high-stability hydrogen production electrode according to claim 1 or 2, wherein the low-nickel high-aluminum Raney nickel alloy powder is binary Ni-Al alloy powder or multi-element alloy powder; The multi-element alloy powder is selected from one or more of Ni-Al-Mo, ni-Al-Cr, ni-Al-Fe and Ni-Al-Co, wherein the total mass ratio of nickel is 40% -75%.
  4. 4. The method for efficiently preparing the high-performance high-stability hydrogen production electrode according to claim 1, wherein the mass ratio of nickel to aluminum in the high-nickel low-aluminum type Raney nickel alloy powder is 90:10.
  5. 5. The method for efficiently preparing a high-performance high-stability hydrogen-producing electrode according to claim 1 or 3, wherein when the low-nickel high-aluminum Raney nickel alloy powder is a binary alloy powder, the mass ratio of nickel to aluminum is 70:30.
  6. 6. The method for efficiently preparing a high-performance high-stability hydrogen-producing electrode according to claim 3, wherein when the low-nickel high-aluminum Raney nickel alloy powder is Ni-Al-Mo ternary alloy powder, the mass ratio of nickel, molybdenum and aluminum is 50:20:30.
  7. 7. The method for efficiently preparing the high-performance high-stability hydrogen production electrode according to claim 1, wherein the alkali liquid adopted in the alkali liquid activation treatment is NaOH or KOH solution with the concentration of 4-8 mol/L, the treatment temperature is 60-90 ℃, and the treatment time is 1-4 hours.
  8. 8. A hydrogen-producing electrode, characterized by being produced by the method of any one of claims 1 to 7.

Description

Method for efficiently preparing high-performance high-stability hydrogen production electrode Technical Field The invention relates to the technical field of electrode material preparation, in particular to a method for efficiently preparing a high-performance high-stability hydrogen production electrode. Background In the alkaline water electrolysis hydrogen production technology, the electrode is one of core components, and the performance of the electrode directly influences the hydrogen production efficiency and the system stability. Currently, the mainstream hydrogen-producing electrode usually uses a pure nickel woven net as a substrate, and a layer of catalyst material (such as Raney nickel) is coated on the surface of the pure nickel woven net to improve the catalytic activity of the electrode. In the prior art, the method for coating the catalyst on the surface of the nickel screen mainly comprises electrodeposition, chemical deposition, powder metallurgy sintering, plasma spraying and the like. Among them, the plasma spraying technology is suitable for large-area and complex-shape substrates, and can form a coating with good binding force, so that the plasma spraying technology becomes a mainstream method for preparing electrode nets. Typical plasma spray processes employ a single spray gun that feeds a catalyst powder (e.g., raney nickel alloy powder) into a high temperature plasma jet for melting and high velocity spraying onto a nickel mesh substrate to form a coating. Then, the coating is subjected to activation treatment by alkali liquor (such as NaOH solution) to dissolve out the aluminum component in the coating, so as to form the active Raney nickel catalyst layer with high specific surface area and porous structure. However, existing single gun plasma spray processes suffer from the inherent disadvantage that the composition of the coating (nickel to aluminum ratio) directly affects the performance of the final electrode when spraying the Raney nickel catalyst. If Raney nickel powder with high aluminum content is adopted, after alkali liquor activation, aluminum is dissolved out in a large amount, and the formed coating has a plurality of pores, large specific surface area and high catalytic activity, but the coating is easy to peel off from the substrate under the stress generated by frequent start-up and stop or long-term operation of a hydrogen production system due to weak bonding interface between a metal nickel skeleton and a nickel screen substrate in the coating, so that the electrode is deactivated and the service life is shortened. On the contrary, if Raney nickel powder with high nickel content is adopted, the binding force between the coating and the nickel screen matrix is strong, the stability is good, but the pore structure formed after activation is undeveloped, the active sites are few, the catalytic activity of the electrode is low, and the hydrogen production efficiency is poor. Therefore, it is difficult in the prior art to achieve a good balance between "high catalytic activity" and "high binding force/stability" of the electrode. Disclosure of Invention The invention aims to provide a method for efficiently preparing a high-performance high-stability hydrogen production electrode, which aims to solve the prior technical problems in the prior art. In order to achieve the purpose, the invention provides the following technical scheme that the method for efficiently preparing the high-performance high-stability hydrogen production electrode comprises the following steps: Spraying a Raney nickel catalyst coating on a nickel screen substrate by adopting a multi-spray gun plasma spraying system, wherein the multi-spray gun plasma spraying system is provided with at least two plasma spray guns which are arranged front and back along the spraying direction; the spraying process is multilayer gradient spraying, and specifically comprises the following steps: Spraying a first layer of catalyst coating to the nickel screen matrix by using a plasma spray gun at the forefront end, wherein spraying powder used for the first layer of catalyst coating is high-nickel low-aluminum Raney nickel alloy powder, and the mass ratio of nickel to aluminum is (85-95) (15-5); Spraying an outermost catalyst coating on the surface of the first catalyst coating by using a plasma spray gun at the rearmost end, wherein spraying powder used for the outermost catalyst coating is low-nickel high-aluminum Raney nickel alloy powder, and the mass ratio of nickel to aluminum is (40-75) (60-25); The multi-layer gradient spraying is completed in one continuous spraying process; And after the spraying is finished, alkali liquor activation treatment is carried out on the electrode network with the gradient coating, and the aluminum component in the coating is dissolved out to obtain the hydrogen production electrode. The multi-spray gun plasma spraying system is further provided with three or more plasma spra