Anode for hydrogen production by alkaline water and method for manufacturing the same

Abstract

The application discloses a kind of basic water hydrogen production anode and its preparation method, including taking ruthenium nitrate solution, nickel nitrate, cobalt nitrate, mix to completely dissolve, make its atomic percentage content Ru:30%, Ni:14%, Co:56%, total metal concentration reaches 220g / L, again according to the proportion of graphene content 0.4g / L in solution to the solution of dissolving ruthenium nitrate, nickel nitrate, cobalt nitrate is added graphene aqueous solution, then it is mixed uniformly with ultrasonic instrument, and the surface active coating coating fluid is obtained;First gradient intermediate layer atomic percentage content Ru:8%, Ni:74%, Co:18%, second gradient intermediate layer atomic percentage content Ru:16%, Ni:54%, Co:30%, third gradient intermediate layer atomic percentage content Ru:25%.Its purpose is to provide a kind of oxygen evolution overpotential low at high current density, long service life basic water hydrogen production anode and its preparation method.

Description

TECHNICAL FIELD

[0001] The present application relates to an anode for alkaline water hydrogen production and a preparation method thereof. BACKGROUND

[0002] With the increasing strength of carbon emission reduction "carbon neutralization", the demand for clean energy and renewable energy is increasing, and hydrogen energy will become an important part of the energy system. Water electrolysis hydrogen production technology has many advantages. On the one hand, the raw materials are easy to obtain, the equipment is simple, and the operation and management are convenient. On the other hand, the production process of water electrolysis hydrogen production is pollution-free, and the hydrogen produced is recognized as high purity, low impurity content and suitable for various hydrogen use places among many hydrogen production methods.

[0003] The anode for alkaline water hydrogen production is completely different from the anode for chlor-alkali. From the reaction mechanism, the former belongs to oxygen evolution anode, and the latter belongs to chlorine evolution anode. From the operation condition, the former operates in alkaline water, and the latter operates in brine. From the substrate selection, the former usually uses nickel substrate, and the latter usually uses titanium substrate.

[0004] At present, the oxygen evolution anode applied to water electrolysis hydrogen production device which is relatively mature has:

[0005] (1) Nickel has good corrosion resistance in alkaline medium. Among metal elements, the oxygen evolution overpotential of nickel is relatively low, but compared with electrodes with catalytic layer, the oxygen evolution overpotential is still high. Because the price is relatively low, it is widely used as alkaline water electrolysis anode;

[0006] (2) Precious metal oxides have good hydrogen evolution and oxygen evolution catalytic activity, but they are expensive;

[0007] (3) ABO3 perovskite oxides and AB2O4 spinel oxides have low oxygen evolution overpotential, good corrosion resistance and low cost, and are considered to be the most promising anode catalytic materials at present.

[0008] Under alkaline conditions, the anode reaction of water electrolysis hydrogen production is: 4OH - -4e - = 2H2O + O2↑

[0009] At present, the operating conditions of alkaline water hydrogen production electrolytic cell are usually 70-90℃, current density 2KA / m 2 -4KA / m 2 , and the electrolyte is 30-32% NaOH or KOH. With the continuous maturity of technology, it can operate at high current density, that is, at 4KA / m 2The above operation at the current density is a future development trend, and thus an electrode with low oxygen evolution overpotential and long service life at high current density is required, and the existing anode for alkaline water hydrogen production generally does not have such performance. SUMMARY

[0010] The present application aims to provide an anode for alkaline water hydrogen production, which has low oxygen evolution overpotential and long service life at high current density of 6KA / m 2 and above, and a preparation method thereof.

[0011] The anode for alkaline water hydrogen production of the present application is prepared by the following steps:

[0012] A. Prepare at least one soluble salt of noble metal elements, the noble metal elements being ruthenium Ru, iridium Ir, rhodium Rh, palladium Pd or platinum Pt; and prepare at least one soluble salt of transition metal elements, the transition metal elements being lanthanum La, iron Fe, cobalt Co, nickel Ni or copper Cu;

[0013] B. Dissolve the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 20%-35% and the molar percentage of the transition metal elements is 65%-80% according to the metal composition, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0014] Dissolve the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the first intermediate layer, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 5%-9% and the molar percentage of the transition metal elements is 91%-95% according to the metal composition, to obtain the coating liquid stock solution for the first intermediate layer;

[0015] Dissolve the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the second intermediate layer, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 10%-14% and the molar percentage of the transition metal elements is 86%-90% according to the metal composition, to obtain the coating liquid stock solution for the second intermediate layer;

[0016] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 15%-19% and the molar percentage of transition metal element being 81%-85% according to the metal composition.

[0017] C. The graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0018] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the first intermediate layer;

[0019] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the second intermediate layer;

[0020] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the third intermediate layer;

[0021] D. The metal substrate for alkaline water hydrogen production anode is sandblasted and pickled to roughen the surface, and the metal substrate contains nickel element;

[0022] E. The metal substrate obtained in step D is heat treated in an oxygen-containing atmosphere, with the heat treatment temperature being 350-550℃ and the time being 20-60 minutes, to oxidize the surface and obtain a metal substrate containing nickel oxide;

[0023] F. The first intermediate layer coating liquid stock solution obtained in step C is coated on the metal substrate obtained in step E, and then the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, with the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, and 10-50 minutes of holding, and after the heat treatment is completed, the metal substrate is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, with the single-layer coating amount of the active coating layer being 4.2 g / m2-6.3 g / m 2 ;

[0024] Then the first intermediate layer obtained in step C is coated again with the coating liquid stock solution, and the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, the furnace temperature being raised to 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed again on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0025] G. The second intermediate layer coating liquid stock solution obtained in step C is coated on the metal substrate obtained in step F, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, the furnace temperature being raised to 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0026] Then the second intermediate layer coating liquid stock solution obtained in step C is coated again, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, the furnace temperature being raised to 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed again on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0027] H. The third intermediate layer coating liquid stock solution obtained in step C is coated on the metal substrate obtained in step G, and the metal substrate coated with the third intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, the furnace temperature being raised to 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0028] Then the third intermediate layer obtained in step C is coated with the coating solution again, and then the metal substrate coated with the third intermediate layer coating solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions are 350-400°C, holding for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer is 4.2g / m 2 -6.3g / m 2 ;

[0029] I. The surface layer of the anode substrate obtained in step C is coated with the active coating solution, and then the metal substrate coated with the coating solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions are 350-400°C, holding for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer is 4.2g / m 2 -6.3g / m 2 ;

[0030] J. Step I is repeated again, and the cycle is repeated until the total coating amount of the active coating layer on the surface of the metal substrate is ≥50g / m 2 ;

[0031] K. The metal substrate obtained in step J is heat treated, the heat treatment temperature is 350-500°C, the heat treatment time is 50-100 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an alkaline water hydrogen anode is obtained.

[0032] Preferably, in step B, two or more soluble salts of noble metal elements and two or more soluble salts of transition metal elements are dissolved in water to prepare the coating solution for the surface layer of the anode substrate, the total metal concentration in the aqueous solution is 210g / L-240g / L, and the molar percentage of noble metal elements is 23%-33% and the molar percentage of transition metal elements is 67%-77% according to the metal composition.

[0033] At least one soluble salt of a noble metal element and at least one soluble salt of a transition metal element are dissolved in water to prepare the coating solution for the first intermediate layer, the total metal concentration in the aqueous solution is 210g / L-240g / L, and the molar percentage of noble metal elements is 6%-8% and the molar percentage of transition metal elements is 92%-94% according to the metal composition.

[0034] The second intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 210 g / L-240 g / L, and the molar percentage of noble metal element is 11%-13% and the molar percentage of transition metal element is 87%-89% according to the metal composition;

[0035] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 210 g / L-240 g / L, and the molar percentage of noble metal element is 16%-18% and the molar percentage of transition metal element is 82%-84% according to the metal composition;

[0036] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0037] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0038] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0039] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer.

[0040] Preferably, in step B, the anode substrate surface layer coating liquid stock solution is prepared by dissolving two or more soluble salts of noble metal elements and two or more soluble salts of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal element is 26%-30% and the molar percentage of transition metal element is 70%-74% according to the metal composition;

[0041] The first intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal element is 7% and the molar percentage of transition metal element is 93% according to the metal composition.

[0042] The second intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal element is 12% and the molar percentage of transition metal element is 88% according to the metal composition.

[0043] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal element is 17% and the molar percentage of transition metal element is 82% according to the metal composition.

[0044] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, and the proportion of graphene in the graphene aqueous solution is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer.

[0045] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, and the proportion of graphene in the graphene aqueous solution is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the first intermediate layer.

[0046] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, and the proportion of graphene in the graphene aqueous solution is 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the second intermediate layer.

[0047] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, and the proportion of graphene in the graphene aqueous solution is 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the third intermediate layer.

[0048] Preferably, the step D of pickling the metal substrate of the anode for alkaline water electrolysis is using 18wt% hydrochloric acid, and the metal substrate of the anode for alkaline water electrolysis is pickled by heating the 18wt% hydrochloric acid to boiling for 3-5 minutes;

[0049] Preferably, the soluble inorganic salt of the ruthenium element is ruthenium nitrate, the soluble inorganic salt of the iridium element is iridium nitrate, the soluble inorganic salt of the lanthanum element is lanthanum nitrate, the soluble inorganic salt of the nickel element is nickel nitrate, the soluble inorganic salt of the cobalt element is cobalt nitrate, and the single-layer coating amount of the active coating is 5.6g / m 2 6.0g / m 2 .

[0050] The preparation method of the anode for alkaline water electrolysis provided by the application comprises the following steps:

[0051] A. preparing at least one soluble salt of noble metal elements, wherein the noble metal elements are ruthenium Ru, iridium Ir, rhodium Rh, palladium Pd or platinum Pt; and preparing at least one soluble salt of transition metal elements, wherein the transition metal elements are lanthanum La, iron Fe, cobalt Co, nickel Ni or copper Cu;

[0052] B. dissolving the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 20%-35% and the molar percentage of the transition metal elements is 65%-80% according to the metal composition, thereby obtaining the coating liquid stock solution for the surface layer of the anode substrate;

[0053] B. dissolving the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 20%-35% and the molar percentage of the transition metal elements is 65%-80% according to the metal composition, thereby obtaining the coating liquid stock solution for the surface layer of the anode substrate;

[0054] B. dissolving the at least one soluble salt of noble metal elements and the at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200g / L-250g / L, and the molar percentage of the noble metal elements is 20%-35% and the molar percentage of the transition metal elements is 65%-80% according to the metal composition, thereby obtaining the coating liquid stock solution for the surface layer of the anode substrate;

[0055] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 15%-19% and the molar percentage of transition metal element being 81%-85% according to the metal composition.

[0056] C. The graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0057] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the first intermediate layer;

[0058] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the second intermediate layer;

[0059] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the third intermediate layer;

[0060] D. The metal substrate for alkaline water hydrogen production anode is sandblasted and pickled to roughen the surface, and the metal substrate contains nickel element;

[0061] E. The metal substrate obtained in step D is heat treated in an oxygen-containing atmosphere, with the heat treatment temperature being 350-550℃ and the time being 20-60 minutes, to oxidize the surface and obtain a metal substrate containing nickel oxide;

[0062] F. The first intermediate layer coating liquid stock solution obtained in step C is coated on the metal substrate obtained in step E, and then the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, with the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, and 10-50 minutes of holding, and after the heat treatment is completed, the metal substrate is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, with the single-layer coating amount of the active coating layer being 4.2 g / m2-6.3 g / m 2 ;

[0063] The first intermediate layer obtained in Step C is then coated with the coating liquid stock solution, and the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and then rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0064] G. The second intermediate layer coating liquid stock solution obtained in Step C is coated on the metal substrate obtained in Step F, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and then rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0065] The second intermediate layer coating liquid stock solution obtained in Step C is then coated, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and then rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0066] H. The third intermediate layer coating liquid stock solution obtained in Step C is coated on the metal substrate obtained in Step G, and the metal substrate coated with the third intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and then rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 — 6.3 g / m 2 ;

[0067] Then the third intermediate layer obtained in step C is coated with the coating solution again, and then the metal substrate coated with the third intermediate layer coating solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions are 350-400°C, holding for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer is 4.2g / m 2 -6.3g / m 2 ;

[0068] I. The surface layer of the anode substrate obtained in step C is coated with the active coating solution, and then the metal substrate coated with the coating solution is heat treated in an oxygen-containing atmosphere, the heat treatment conditions are 350-400°C, holding for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer is 4.2g / m 2 -6.3g / m 2 ;

[0069] J. Step I is repeated again, and the cycle is repeated until the total coating amount of the active coating layer on the surface of the metal substrate is ≥50g / m 2 ;

[0070] K. The metal substrate obtained in step J is heat treated, the heat treatment temperature is 350-500°C, the heat treatment time is 50-100 minutes, and then the metal substrate is rapidly cooled to room temperature after the heat treatment is completed, and an alkaline water hydrogen anode is obtained.

[0071] Preferably, in step B, two or more soluble salts of noble metal elements and two or more soluble salts of transition metal elements are dissolved in water to prepare the coating solution for the surface layer of the anode substrate, the total metal concentration in the aqueous solution is 210g / L-240g / L, and the molar percentage of noble metal elements is 23%-33% and the molar percentage of transition metal elements is 67%-77% according to the metal composition.

[0072] At least one soluble salt of a noble metal element and at least one soluble salt of a transition metal element are dissolved in water to prepare the coating solution for the first intermediate layer, the total metal concentration in the aqueous solution is 210g / L-240g / L, and the molar percentage of noble metal elements is 6%-8% and the molar percentage of transition metal elements is 92%-94% according to the metal composition.

[0073] The second intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 210 g / L-240 g / L, and the molar percentage of noble metal element is 11%-13% and the molar percentage of transition metal element is 87%-89% according to the metal composition;

[0074] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, so that the total metal concentration in the aqueous solution is 210 g / L-240 g / L, and the molar percentage of noble metal element is 16%-18% and the molar percentage of transition metal element is 82%-84% according to the metal composition;

[0075] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0076] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0077] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0078] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, wherein the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer.

[0079] Preferably, in step B, the anode substrate surface layer coating liquid stock solution is prepared by dissolving two or more soluble salts of noble metal elements and two or more soluble salts of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal element is 26%-30% and the molar percentage of transition metal element is 70%-74% according to the metal composition;

[0080] The first intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal element being 7%, and the molar percentage of transition metal element being 93%, to obtain the first intermediate layer coating liquid stock solution;

[0081] The second intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal element being 12%, and the molar percentage of transition metal element being 88%, to obtain the second intermediate layer coating liquid stock solution;

[0082] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal element being 17%, and the molar percentage of transition metal element being 82%, to obtain the third intermediate layer coating liquid stock solution;

[0083] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the anode substrate surface layer;

[0084] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the first intermediate layer;

[0085] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the second intermediate layer;

[0086] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the third intermediate layer.

[0087] Preferably, in step D, the metal substrate of the anode for alkaline water hydrogen production is acid-washed using 18wt% hydrochloric acid. The 18wt% hydrochloric acid is heated to boiling and then acid-washed on the metal substrate of the anode for alkaline water hydrogen production for 3-5 minutes.

[0088] Preferably, the soluble inorganic salt of ruthenium is ruthenium nitrate, the soluble inorganic salt of iridium is iridium nitrate, the soluble inorganic salt of lanthanum is lanthanum nitrate, the soluble inorganic salt of nickel is nickel nitrate, and the soluble inorganic salt of cobalt is cobalt nitrate. The single-layer coating weight of the active coating is 5.6 g / m². 2 —6.0g / m 2 .

[0089] The present invention relates to an anode for alkaline water hydrogen production and its preparation method. The method involves dissolving at least one soluble salt of a noble metal element (Ru, Ir, Rh, Pd, Pt) and at least one soluble salt of a transition metal element (La, Fe, Co, Ni, Cu) in water, with the total metal concentration in the aqueous solution being 200 g / L–250 g / L. Based on the metal composition, graphene is added to the aqueous solution at a ratio of 0.1 g / L–3 g / L. The salt solution is then stirred using an ultrasonic mixer to ensure uniform mixing, resulting in an active coating solution. Adding graphene to the active coating solution improves the anode surface morphology. The anode for water electrolysis hydrogen production prepared using this active coating solution, after electrolysis at 80°C and 32% NaOH for 2000 hours, yields a hydrogen concentration of 6 kA / m³. 2 Electrolysis for 1278 hours, 8KA / m 2 After 722 hours of electrolysis, the coating residue was 75%; 6KA / m 2 At that time, the oxygen evolution overpotential was measured to be 180 mV. Therefore, it can be seen that the anode for alkaline water hydrogen production and its preparation method of the present invention have low oxygen evolution overpotential, within the range of 6 kA / m² to 8 kA / m². 2 It features a long service life under high current density.

[0090] The alkaline water-based hydrogen production anode and its preparation method of the present invention involve adding graphene to the active coating solution to improve the microstructure of the anode coating, resulting in a honeycomb-like surface with fine and small surface cracks, creating an uneven surface characteristic and increasing the surface roughness of the electrode. This increases the number of active sites on the anode surface, enhances the electrocatalytic activity of the electrode, and effectively reduces the oxygen evolution overpotential. Furthermore, the alkaline water-based hydrogen production anode of the present invention employs a gradient coating method, which improves the adhesion between the substrate and the coating, effectively prevents abrupt changes in the composition of the substrate and the coating, and extends the service life of the electrode. Through these two methods, the alkaline water-based hydrogen production anode possesses three advantages:

[0091] (1) Low oxygen evolution overpotential;

[0092] (2) capable of operating at high current density of 6 KA / m 2 and above;

[0093] (3) has a longer service life.

[0094] Further details and features of the anode for hydrogen production by alkaline water and the method for preparing the same can be clearly understood by reading the following detailed description of the embodiments. DETAILED DESCRIPTION

[0095] The anode for hydrogen production by alkaline water of the present application is prepared by the following steps:

[0096] A. preparing at least one soluble salt of noble metal elements, the noble metal elements being ruthenium Ru, iridium Ir, rhodium Rh, palladium Pd or platinum Pt; and preparing at least one soluble salt of transition metal elements, the transition metal elements being lanthanum La, iron Fe, cobalt Co, nickel Ni or copper Cu;

[0097] B. using at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200 g / L-250 g / L, and according to the metal composition, the molar percentage of noble metal elements is 20%-35%, and the molar percentage of transition metal elements is 65%-80%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0098] using at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements to prepare a coating liquid stock solution for the first intermediate layer, so that the total metal concentration in the aqueous solution is 200 g / L-250 g / L, and according to the metal composition, the molar percentage of noble metal elements is 5%-9%, and the molar percentage of transition metal elements is 91%-95%, to obtain the coating liquid stock solution for the first intermediate layer;

[0099] using at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements to prepare a coating liquid stock solution for the second intermediate layer, so that the total metal concentration in the aqueous solution is 200 g / L-250 g / L, and according to the metal composition, the molar percentage of noble metal elements is 10%-14%, and the molar percentage of transition metal elements is 86%-90%, to obtain the coating liquid stock solution for the second intermediate layer;

[0100] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 15%-19% and the molar percentage of transition metal element being 81%-85% according to the metal composition.

[0101] C. The graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer;

[0102] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the first intermediate layer;

[0103] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the second intermediate layer;

[0104] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the third intermediate layer;

[0105] D. The metal substrate for alkaline water hydrogen production anode is sandblasted and pickled to roughen the surface, and the metal substrate contains nickel element;

[0106] E. The metal substrate obtained in step D is heat treated in an oxygen-containing atmosphere, with the heat treatment temperature being 350-550℃ and the time being 20-60 minutes, to oxidize the surface and obtain a metal substrate containing nickel oxide;

[0107] F. The first intermediate layer coating liquid stock solution obtained in step C is coated on the metal substrate obtained in step E, and then the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere, with the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, and 10-50 minutes of holding, and after the heat treatment is completed, the metal substrate is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, with the single-layer coating amount of the active coating layer being 4.2 g / m2-6.3 g / m 2 ;

[0108] The first intermediate layer obtained in Step C is then coated again with the coating liquid stock solution, and the metal substrate coated with the first intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and after the heat treatment is completed, it is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0109] G. The second intermediate layer coating liquid stock solution obtained in Step C is coated on the metal substrate obtained in Step F, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and after the heat treatment is completed, it is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0110] The second intermediate layer coating liquid stock solution obtained in Step C is then coated again, and the metal substrate coated with the second intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and after the heat treatment is completed, it is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate again, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0111] H. The third intermediate layer coating liquid stock solution obtained in Step C is coated on the metal substrate obtained in Step G, and the metal substrate coated with the third intermediate layer coating liquid stock solution is heat treated in an oxygen-containing atmosphere under the conditions of 350-400°C for 5-10 minutes, the furnace temperature is raised to 400-550°C within 5 minutes, and heat treated for 10-50 minutes, and after the heat treatment is completed, it is rapidly cooled to room temperature, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0112] Then the third intermediate layer obtained in step C is coated with the coating solution stock solution again, and then the metal substrate coated with the third intermediate layer coating solution stock solution is subjected to heat treatment in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, holding for 5-10 minutes, the furnace temperature being raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then rapidly cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single-layer coating amount of the active coating layer being 4.2g / m 2 -6.3g / m 2 ;

[0113] I. The surface layer of the anode substrate obtained in step C is coated with the active coating solution, and then the metal substrate coated with the coating solution is subjected to heat treatment in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, holding for 5-10 minutes, the furnace temperature being raised to 400-550°C within 5 minutes, holding for 10-50 minutes, and then rapidly cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single-layer coating amount of the active coating layer being 4.2g / m 2 -6.3g / m 2 ;

[0114] J. Step I is repeated again, and the cycle is repeated until the total coating amount of the active coating layer on the surface of the metal substrate is ≥50g / m 2 ;

[0115] The coating method disclosed in steps B to J above is a gradient coating method.

[0116] K. The metal substrate obtained in step J is subjected to sintering heat treatment, the sintering heat treatment temperature being 350-500°C, the sintering heat treatment time being 50-100 minutes, and then rapidly cooling to room temperature after the heat treatment is completed, to obtain an anode for alkaline water hydrogen production.

[0117] As a further improvement of the present application, in step B above, the coating solution stock solution for the surface layer of the anode substrate is prepared by dissolving two or more kinds of soluble salts of noble metal elements and two or more kinds of soluble salts of transition metal elements in water, the total metal concentration in the aqueous solution being 210-240g / L, and the molar percentage of the noble metal elements being 23-33% and the molar percentage of the transition metal elements being 67-77% according to the metal composition.

[0118] The first intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal element being 6%-8%, and the molar percentage of transition metal element being 92%-94%, to obtain the first intermediate layer coating liquid stock solution;

[0119] The second intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal element being 11%-13%, and the molar percentage of transition metal element being 87%-89%, to obtain the second intermediate layer coating liquid stock solution;

[0120] The third intermediate layer coating liquid stock solution is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal element being 16%-18%, and the molar percentage of transition metal element being 82%-84%, to obtain the third intermediate layer coating liquid stock solution;

[0121] In step C, the graphene aqueous solution is added to the anode substrate surface layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the anode substrate surface layer;

[0122] The graphene aqueous solution is added to the first intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the first intermediate layer;

[0123] The graphene aqueous solution is added to the second intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the second intermediate layer;

[0124] The graphene aqueous solution is added to the third intermediate layer coating liquid stock solution obtained in step B, with the proportion of graphene being 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to obtain an active coating solution for the third intermediate layer.

[0125] As a further improvement of the present application, the step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0126] The step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0127] The step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0128] The step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0129] The step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0130] The step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 220 g / L-230 g / L, according to the metal composition, the molar percentage of noble metal elements is 26%-30%, and the molar percentage of transition metal elements is 70%-74%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0131] The graphene aqueous solution is added to the coating liquid stock solution for the second intermediate layer obtained in step B, the proportion of graphene in the graphene aqueous solution is 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating coating liquid for the second intermediate layer.

[0132] The graphene aqueous solution is added to the coating liquid stock solution for the third intermediate layer obtained in step B, the proportion of graphene in the graphene aqueous solution is 0.6 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating coating liquid for the third intermediate layer.

[0133] As a further improvement of the present application, the acid pickling of the metal substrate of the alkaline water hydrogen production anode in step D above is carried out by using 18wt% hydrochloric acid, and the metal substrate of the alkaline water hydrogen production anode is pickled by heating the 18wt% hydrochloric acid to boiling for 3-5 minutes;

[0134] As a further improvement of the present application, the soluble inorganic salt of ruthenium element is ruthenium nitrate, the soluble inorganic salt of iridium element is iridium nitrate, the soluble inorganic salt of lanthanum element is lanthanum nitrate, the soluble inorganic salt of nickel element is nickel nitrate, the soluble inorganic salt of cobalt element is cobalt nitrate, and the single-layer coating amount of the active coating is 5.6 g / m 2 -6.0 g / m 2 .

[0135] The preparation method of the alkaline water hydrogen production anode of the present application comprises the following steps:

[0136] A. Prepare at least one soluble salt of noble metal elements, the noble metal elements being ruthenium Ru, iridium Ir, rhodium Rh, palladium Pd or platinum Pt; and prepare at least one soluble salt of transition metal elements, the transition metal elements being lanthanum La, iron Fe, cobalt Co, nickel Ni or copper Cu;

[0137] B. Dissolve at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements in water to prepare a coating liquid stock solution for the surface layer of the anode substrate, so that the total metal concentration in the aqueous solution is 200 g / L-250 g / L, and the molar percentage of noble metal elements is 20%-35% and the molar percentage of transition metal elements is 65%-80% according to the metal composition, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0138] The first intermediate layer coating liquid is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 5%-9% and the molar percentage of transition metal element being 91%-95% according to the metal composition.

[0139] The second intermediate layer coating liquid is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 10%-14% and the molar percentage of transition metal element being 86%-90% according to the metal composition.

[0140] The third intermediate layer coating liquid is prepared by dissolving at least one soluble salt of noble metal element and at least one soluble salt of transition metal element in water, with the total metal concentration in the aqueous solution being 200 g / L-250 g / L, and the molar percentage of noble metal element being 15%-19% and the molar percentage of transition metal element being 81%-85% according to the metal composition.

[0141] C. The graphene aqueous solution is added to the anode substrate surface layer coating liquid obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the anode substrate surface layer.

[0142] The graphene aqueous solution is added to the first intermediate layer coating liquid obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the first intermediate layer.

[0143] The graphene aqueous solution is added to the second intermediate layer coating liquid obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the second intermediate layer.

[0144] The graphene aqueous solution is added to the third intermediate layer coating liquid obtained in step B, with the proportion of graphene being 0.1 g / L-3 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain an active coating solution for the third intermediate layer.

[0145] D. sanding and pickling the metal substrate of the anode for alkaline water hydrogen production to roughen the surface, the metal substrate containing nickel element;

[0146] E. heat treating the metal substrate obtained in step D in an oxygen-containing atmosphere, the heat treatment temperature being 350-550℃, the time being 20-60 minutes, to oxidize the surface and obtain a metal substrate containing nickel oxide;

[0147] F. coating the metal substrate obtained in step E with the first intermediate layer coating liquid obtained in step C, and then heat treating the metal substrate coated with the first intermediate layer coating liquid in an oxygen-containing atmosphere, the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, 10-50 minutes of holding, and then rapidly cooling to room temperature after the heat treatment is completed, and generating an active coating on the outer surface of the metal substrate, the single-layer coating amount of the active coating being 4.2g / m 2 ;

[0148] Then, the metal substrate coated with the first intermediate layer coating liquid is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, 10-50 minutes of holding, and then rapidly cooling to room temperature after the heat treatment is completed, and generating an active coating on the outer surface of the metal substrate again, the single-layer coating amount of the active coating being 4.2g / m 2 —6.3g / m 2 ;

[0149] G. coating the metal substrate obtained in step F with the second intermediate layer coating liquid obtained in step C, and then heat treating the metal substrate coated with the second intermediate layer coating liquid in an oxygen-containing atmosphere, the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, 10-50 minutes of holding, and then rapidly cooling to room temperature after the heat treatment is completed, and generating an active coating on the outer surface of the metal substrate, the single-layer coating amount of the active coating being 4.2g / m 2 —6.3g / m 2 ;

[0150] Then, the metal substrate coated with the second intermediate layer coating liquid is heat treated in an oxygen-containing atmosphere, the heat treatment conditions being 350-400℃, 5-10 minutes of holding, the furnace temperature being raised to 400-550℃ within 5 minutes, 10-50 minutes of holding, and then rapidly cooling to room temperature after the heat treatment is completed, and generating an active coating on the outer surface of the metal substrate again, the single-layer coating amount of the active coating being 4.2g / m2 - 6.3 g / m 2 ;

[0151] H, coating the third intermediate layer coating solution obtained in step C on the metal substrate obtained in step G, and then performing heat treatment on the metal substrate coated with the third intermediate layer coating solution in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0152] H, coating the third intermediate layer coating solution obtained in step C on the metal substrate obtained in step G, and then performing heat treatment on the metal substrate coated with the third intermediate layer coating solution in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0153] H, coating the third intermediate layer coating solution obtained in step C on the metal substrate obtained in step G, and then performing heat treatment on the metal substrate coated with the third intermediate layer coating solution in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 - 6.3 g / m 2 ;

[0154] H, coating the third intermediate layer coating solution obtained in step C on the metal substrate obtained in step G, and then performing heat treatment on the metal substrate coated with the third intermediate layer coating solution in an oxygen-containing atmosphere, the heat treatment conditions being 350-400°C, 5-10 minutes of holding, 400-550°C within 5 minutes, 10-50 minutes of holding, and rapid cooling to room temperature after the heat treatment is completed, and an active coating layer is formed on the outer surface of the metal substrate, the single layer coating amount of the active coating layer being 4.2 g / m 2 ;

[0155] The coating method disclosed in the above steps B to J is a gradient coating method.

[0156] K, performing sintering heat treatment on the metal substrate obtained in step J, the sintering heat treatment temperature being 350-500°C, the sintering heat treatment time being 50-100 minutes, and rapid cooling to room temperature after the heat treatment is completed, to obtain an anode for alkaline water hydrogen production.

[0157] As a further improvement of the present application, the step B above is to dissolve the soluble salts of two or more noble metal elements and two or more transition metal elements in water to prepare the coating liquid stock solution for the surface layer of the anode substrate, and the total metal concentration in the aqueous solution is 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal elements is 23%-33%, and the molar percentage of transition metal elements is 67%-77%, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0158] The soluble salts of at least one noble metal element and at least one transition metal element are dissolved in water to prepare the coating liquid stock solution for the first intermediate layer, and the total metal concentration in the aqueous solution is 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal elements is 6%-8%, and the molar percentage of transition metal elements is 92%-94%, to obtain the coating liquid stock solution for the first intermediate layer;

[0159] The soluble salts of at least one noble metal element and at least one transition metal element are dissolved in water to prepare the coating liquid stock solution for the second intermediate layer, and the total metal concentration in the aqueous solution is 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal elements is 11%-13%, and the molar percentage of transition metal elements is 87%-89%, to obtain the coating liquid stock solution for the second intermediate layer;

[0160] The soluble salts of at least one noble metal element and at least one transition metal element are dissolved in water to prepare the coating liquid stock solution for the third intermediate layer, and the total metal concentration in the aqueous solution is 210 g / L-240 g / L, according to the metal composition, the molar percentage of noble metal elements is 16%-18%, and the molar percentage of transition metal elements is 82%-84%, to obtain the coating liquid stock solution for the third intermediate layer;

[0161] In the step C, the graphene aqueous solution is added to the coating liquid stock solution for the surface layer of the anode substrate obtained in step B, and the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating solution for the surface layer of the anode substrate;

[0162] The graphene aqueous solution is added to the coating liquid stock solution for the first intermediate layer obtained in step B, and the proportion of graphene is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating solution for the first intermediate layer;

[0163] The graphene aqueous solution is added to the coating liquid stock solution for the second intermediate layer obtained in Step B, the proportion of graphene in the graphene aqueous solution is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating coating liquid for the second intermediate layer.

[0164] The graphene aqueous solution is added to the coating liquid stock solution for the third intermediate layer obtained in Step B, the proportion of graphene in the graphene aqueous solution is 0.2 g / L-2 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed, to obtain the active coating coating liquid for the third intermediate layer.

[0165] As a further improvement of the present application, in Step B above, the coating liquid stock solution for the surface layer of the anode substrate is prepared by dissolving two or more soluble salts of noble metal elements and two or more soluble salts of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal elements is 26%-30% and the molar percentage of transition metal elements is 70%-74% according to the metal composition, to obtain the coating liquid stock solution for the surface layer of the anode substrate;

[0166] The coating liquid stock solution for the first intermediate layer is prepared by dissolving at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal elements is 7% and the molar percentage of transition metal elements is 93% according to the metal composition, to obtain the coating liquid stock solution for the first intermediate layer;

[0167] The coating liquid stock solution for the second intermediate layer is prepared by dissolving at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal elements is 12% and the molar percentage of transition metal elements is 88% according to the metal composition, to obtain the coating liquid stock solution for the second intermediate layer;

[0168] The coating liquid stock solution for the third intermediate layer is prepared by dissolving at least one soluble salt of noble metal elements and at least one soluble salt of transition metal elements in water, so that the total metal concentration in the aqueous solution is 220 g / L-230 g / L, and the molar percentage of noble metal elements is 17% and the molar percentage of transition metal elements is 82% according to the metal composition, to obtain the coating liquid stock solution for the third intermediate layer;

[0169] The step C is to add graphene aqueous solution into the coating liquid stock solution for the surface layer of the anode substrate obtained in step B, wherein the proportion of graphene is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed to obtain the active coating solution for the surface layer of the anode substrate;

[0170] The step C is to add graphene aqueous solution into the coating liquid stock solution for the surface layer of the anode substrate obtained in step B, wherein the proportion of graphene is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed to obtain the active coating solution for the surface layer of the anode substrate;

[0171] The step C is to add graphene aqueous solution into the coating liquid stock solution for the surface layer of the anode substrate obtained in step B, wherein the proportion of graphene is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed to obtain the active coating solution for the surface layer of the anode substrate;

[0172] The step C is to add graphene aqueous solution into the coating liquid stock solution for the surface layer of the anode substrate obtained in step B, wherein the proportion of graphene is 0.5 g / L-1.6 g / L, and then the salt solution is stirred with an ultrasonic mixer to make it uniformly mixed to obtain the active coating solution for the surface layer of the anode substrate.

[0173] As a further improvement of the present application, the acid pickling of the metal substrate of the alkaline water hydrogen production anode in the above step D is carried out by using 18wt% hydrochloric acid, and the metal substrate of the alkaline water hydrogen production anode is pickled by heating the 18wt% hydrochloric acid to boiling for 3-5 minutes;

[0174] As a further improvement of the present application, the soluble inorganic salt of ruthenium element is ruthenium nitrate, the soluble inorganic salt of iridium element is iridium nitrate, the soluble inorganic salt of lanthanum element is lanthanum nitrate, the soluble inorganic salt of nickel element is nickel nitrate, the soluble inorganic salt of cobalt element is cobalt nitrate, and the single-layer coating amount of the active coating is 5.6 g / m 2 —6.0 g / m 2 .

[0175] The mass percentage of each element in the active coating according to the metal component can be detected by an x-ray fluorescence tester.

[0176] Example 1

[0177] Coating liquid preparation: take the ruthenium nitrate solution, nickel nitrate, cobalt nitrate, mix until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, the total metal concentration reaches 220g / L, finally according to the proportion of 0.4g / L of graphene content in the solution to the solution containing ruthenium nitrate, nickel nitrate, cobalt nitrate, add graphene aqueous solution, then mix uniformly with ultrasonic instrument, get the surface active coating liquid; the atomic percentage content of the first gradient intermediate layer is Ru: 8%, Ni: 74%, Co: 18%, the atomic percentage content of the second gradient intermediate layer is Ru: 16%, Ni: 54%, Co: 30%, the atomic percentage content of the third gradient intermediate layer is Ru: 25%, Ni: 34%, Co: 41%, the total metal concentration reaches 220g / L, finally according to the proportion of 0.4g / L of graphene content in the solution to the solution containing ruthenium nitrate, nickel nitrate, cobalt nitrate, add graphene aqueous solution, then mix uniformly with ultrasonic instrument, get the gradient intermediate layer coating liquid.

[0178] Coating and firing: the active coating liquid is evenly brushed on the pretreated metal substrate made of titanium mesh, the coating sequence is: the first gradient intermediate layer 2 times, the second gradient intermediate layer 2 times, the third gradient intermediate layer 2 times, and the surface active coating layer 3 times. After each coating, 400℃ is used for firing, and the heat treatment time is 30 minutes, so that the coating amount is ≥45g / m 2 , and the last heat treatment time is 60 minutes, to obtain the anode for alkaline water hydrogen production.

[0179] After the above-mentioned anode for alkaline water hydrogen production is electrolyzed in 80℃, 32% NaOH for 2000 hours, the oxygen evolution overpotential is measured to be 180mV when 6KA / m 2 is electrolyzed for 1278 hours, 8KA / m2 is electrolyzed for 722 hours, and the coating residual amount is 75%; 6KA / m 2 .

[0180] Example 2

[0181] Preparation of coating solution: Take ruthenium nitrate solution, nickel nitrate, and cobalt nitrate, mix until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, and the total metal concentration reaches 230 g / L. Finally, add graphene aqueous solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 0.4 g / L of graphene content in the solution, and then mix evenly with an ultrasonic instrument to obtain the surface active coating solution; The atomic percentage content of the first gradient intermediate layer is Ru: 8%, Ni: 74%, Co: 18%; the atomic percentage content of the second gradient intermediate layer is Ru: 16%, Ni: 54%, Co: 30%; and the atomic percentage content of the third gradient intermediate layer is Ru: 25%, Ni: 34%, Co: 41%, and the total metal concentration reaches 230 g / L. Finally, add graphene aqueous solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 1 g / L of graphene content in the solution, and then mix evenly with an ultrasonic instrument to obtain the gradient intermediate layer coating solution.

[0182] Coating and firing: The active coating solution is evenly applied to the pre-treated metal substrate made of titanium mesh. The coating sequence is as follows: two coats of the first gradient intermediate layer, two coats of the second gradient intermediate layer, two coats of the third gradient intermediate layer, and three coats of the surface active coating. After each coating, the substrate is fired at 400℃ for 30 minutes to ensure a coating thickness ≥45g / m². 2 The final heat treatment lasted 60 minutes, yielding an anode for hydrogen production from alkaline water.

[0183] After electrolyzing the above-mentioned alkaline water hydrogen production at 80°C in 32% NaOH for 2000 hours, 6KA / m 2 Electrolysis for 1278 hours, 8KA / m² electrolysis for 722 hours, coating residue 70%; 6KA / m² electrolysis for 722 hours. 2 At that time, the oxygen evolution overpotential was measured to be 205mV.

[0184] Comparative Example 1

[0185] Preparation of coating solution: Take ruthenium nitrate solution, nickel nitrate and cobalt nitrate, mix until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, and the total metal concentration reaches 220g / L, to obtain the surface active coating solution; the atomic percentage content of the first gradient intermediate layer is Ru: 8%, Ni: 74%, Co: 18%, the atomic percentage content of the second gradient intermediate layer is Ru: 16%, Ni: 54%, Co: 30%, and the atomic percentage content of the third gradient intermediate layer is Ru: 25%, Ni: 34%, Co: 41%, and the total metal concentration reaches 220g / L, to obtain the gradient intermediate layer coating solution.

[0186] Coating and firing: the active coating liquid is evenly brushed on the pretreated metal substrate made of titanium mesh, and the coating sequence is: 2 times of the first gradient intermediate layer, 2 times of the second gradient intermediate layer, 2 times of the third gradient intermediate layer, and 3 times of the surface active coating layer. After each coating, 400 DEG C is used for firing, and the heat treatment time is 30 minutes, so that the coating amount is greater than or equal to 45 g / m 2 , and the last heat treatment time is 60 minutes, to obtain the alkaline water hydrogen production anode.

[0187] After the above-mentioned alkaline water hydrogen production anode is electrolyzed in 80 DEG C, 32% NaOH for 1000 hours, 6KA / m 2 2 is electrolyzed for 639 hours, 8KA / m 2 2 is electrolyzed for 361 hours, and the coating residual amount is 55%; 6KA / m 2 The oxygen evolution overpotential is 230 mV.

[0188] Comparative Example 2

[0189] Coating liquid preparation: take the ruthenium nitrate solution, nickel nitrate and cobalt nitrate, mix until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, and the total metal concentration reaches 220 g / L, and finally add the graphene aqueous solution to the solution containing ruthenium nitrate, nickel nitrate and cobalt nitrate according to the ratio of 0.25 g / L-1 g / L of graphene content in the solution, and then mix uniformly with the ultrasonic instrument to obtain the active coating liquid.

[0190] Coating and firing: the active coating liquid is evenly brushed on the pretreated metal substrate made of titanium mesh, and the coating sequence is: 2 times of the first gradient intermediate layer, 2 times of the second gradient intermediate layer, 2 times of the third gradient intermediate layer, and 3 times of the surface active coating layer. After each coating, 400 DEG C is used for firing, and the heat treatment time is 30 minutes, so that the coating amount is greater than or equal to 45 g / m 2 , and the last heat treatment time is 60 minutes, to obtain the alkaline water hydrogen production anode.

[0191] After the above-mentioned alkaline water hydrogen production anode is electrolyzed in 80 DEG C, 32% NaOH for 1000 hours, 6KA / m 2 2 is electrolyzed for 639 hours, 8KA / m 2 2 is electrolyzed for 361 hours, and the coating residual amount is 35%; 6KA / m 2 The oxygen evolution overpotential is 185 mV.

[0192] It can be seen from the comparison of the examples and the comparative examples that after the alkaline water hydrogen production anode of the application is electrolyzed in 80 DEG C, 32% NaOH for 2000 hours, 6KA / m 2 2 is electrolyzed for 1278 hours, 8KA / m 2 2 is electrolyzed for 722 hours, and the coating residual amount is 75%; 6KA / m 2At this time, the oxygen evolution overpotential is 180 mV. Thus, the alkaline water hydrogen production anode has the characteristics of low chlorine evolution overpotential and long service life under high current density, thereby ensuring that the water electrolysis hydrogen production complete equipment is small in size, low in energy consumption and long in stable operation time.

[0193] The above-described embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. An anode for producing hydrogen from alkaline water, characterized in that: It is made using the following steps: Take a solution of ruthenium nitrate, nickel nitrate, and cobalt nitrate, mix them until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, and the total metal concentration reaches 220 g / L. Then, add an aqueous graphene solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 0.4 g / L of graphene content in the solution, and mix evenly with an ultrasonic instrument to obtain the surface active coating solution; the atomic percentage content of the first gradient intermediate layer is Ru: 8%, Ni: 74%, Co: 18%; the atomic percentage content of the second gradient intermediate layer is Ru: 16%, Ni: 54%, Co: 30%; and the atomic percentage content of the third gradient intermediate layer is Ru: 25%, Ni: 34%, Co: 41%, with a total metal concentration of 220 g / L. Then, add an aqueous graphene solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 0.4 g / L of graphene content in the solution, and mix evenly with an ultrasonic instrument to obtain the gradient intermediate layer coating solution; The active coating solution was uniformly applied to the pretreated metal substrate made of titanium mesh. The coating sequence was as follows: two layers of the first gradient intermediate layer, two layers of the second gradient intermediate layer, two layers of the third gradient intermediate layer, and three layers of the surface active coating. After each coating, the substrate was fired at 400℃ for 30 minutes to ensure a coating amount of ≥45g / m2. The final heat treatment lasted for 60 minutes to obtain the anode for alkaline water hydrogen production.

2. A method for preparing an anode for hydrogen production from alkaline water, characterized in that: It includes the following steps: Take a solution of ruthenium nitrate, nickel nitrate, and cobalt nitrate, mix them until completely dissolved, so that the atomic percentage content is Ru: 30%, Ni: 14%, Co: 56%, and the total metal concentration reaches 220 g / L. Then, add an aqueous graphene solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 0.4 g / L of graphene content in the solution, and mix evenly with an ultrasonic instrument to obtain the surface active coating solution; the atomic percentage content of the first gradient intermediate layer is Ru: 8%, Ni: 74%, Co: 18%; the atomic percentage content of the second gradient intermediate layer is Ru: 16%, Ni: 54%, Co: 30%; and the atomic percentage content of the third gradient intermediate layer is Ru: 25%, Ni: 34%, Co: 41%, with a total metal concentration of 220 g / L. Then, add an aqueous graphene solution to the solution containing ruthenium nitrate, nickel nitrate, and cobalt nitrate at a ratio of 0.4 g / L of graphene content in the solution, and mix evenly with an ultrasonic instrument to obtain the gradient intermediate layer coating solution; The active coating solution was uniformly applied to the pretreated metal substrate made of titanium mesh. The coating sequence was as follows: two layers of the first gradient intermediate layer, two layers of the second gradient intermediate layer, two layers of the third gradient intermediate layer, and three layers of the surface active coating. After each coating, the substrate was fired at 400℃ for 30 minutes to ensure a coating amount of ≥45g / m2. The final heat treatment lasted for 60 minutes to obtain the anode for alkaline water hydrogen production.