Cerium-tungsten co-doped ruthenium oxide catalyst capable of balancing lattice oxygen consumption and filling

Abstract

The invention relates to a cerium-tungsten co-doped ruthenium oxide catalyst capable of balancing lattice oxygen consumption and filling as well as a preparation method and application of the cerium-tungsten co-doped ruthenium oxide catalyst. According to the preparation method, LOM reaction is activated under a W-RuO2 stable framework by simultaneously utilizing a bridging effect of an AEM-OER catalyst and a promoting effect of CeOx on lattice oxygen vacancy filling, so that consumption and filling of lattice oxygen are balanced, dual optimization of stability and high activity of RuO2 in OER can be realized, and the preparation method is suitable for industrial production. The method effectively overcomes the defects that the technology for improving the stability of RuO2 by purely using W doping is at the cost of sacrificing activity and the technology for activating the lattice oxygen of RuO2 by purely using Ce doping is at the cost of sacrificing stability, and realizes dynamic balance of lattice oxygen consumption and supplement, so that the OER reaction of the LOM mechanism is stably operated, and the stability of the RuO2 is improved. The traditional technical bottleneck that activity and stability cannot be considered at the same time is broken through.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalytic materials and energy materials, and relates to a cerium-tungsten co-doped ruthenium oxide catalyst capable of balancing lattice oxygen consumption and filling, as well as a preparation method and application thereof. Background Art

[0002] Recent studies have found that RuO2 can achieve high catalytic activity in the oxygen evolution reaction (OER) at the anode of acidic water electrolysis through the lattice oxygen mechanism (LOM). This mechanism involves the direct participation of lattice oxygen in the formation of oxygen products, breaking through the activity bottleneck of the traditional adsorption evolution mechanism (AEM). However, a serious problem of the LOM mechanism is the rapid consumption of lattice oxygen. If oxygen vacancies cannot be effectively replenished, it will lead to unstable catalyst structure, Ru loss, and even overall deactivation of the catalyst. In order to alleviate this problem, some studies have attempted to inhibit the LOM reaction by reducing the covalency of the Ru-O bond and instead adopt the AEM mechanism to obtain better stability.

[0003] In the existing technology, although the adsorption evolution mechanism (AEM) is believed to be able to effectively improve the structural stability of RuO2 catalysts under acidic conditions and avoid lattice collapse and ruthenium loss caused by the lattice oxygen mechanism (LOM), this mechanism has significant defects. Because the AEM pathway inhibits the direct participation of lattice oxygen by reducing the covalency of the Ru-O bond, although it improves the stability of the material, it inhibits the reaction activity and significantly reduces the catalytic activity. Therefore, the current AEM-based strategy is difficult to balance high catalytic activity and structural stability, and still faces key problems such as insufficient activity, high energy barriers and unsatisfactory long-term performance, which limits its practical application in efficient acidic oxygen evolution reactions. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that high stability and high catalytic activity of ruthenium dioxide (RuO2)-based catalysts in the OER reaction cannot be compatible at the same time, thereby providing a catalyst with improved oxygen vacancy compensation ability and achieving a stable balance between lattice oxygen consumption and regeneration, in particular a high-efficiency and stable ruthenium dioxide (RuO2)-based catalyst suitable for oxygen evolution reaction under acidic conditions. The present invention effectively solves the problem of rapid activity decay of RuO2 catalysts with existing LOM mechanism in the catalytic OER process due to the rapid consumption of lattice oxygen, which makes it difficult to compensate for oxygen vacancies, by introducing a Ce and W dual-doping strategy, and realizes a virtuous cycle of lattice oxygen consumption and compensation, thereby breaking through the performance trade-off problem of the traditional AEM method and improving the activity and durability of the catalyst.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions.

[0006] The first aspect of the present invention provides a method for preparing a cerium-tungsten co-doped ruthenium oxide catalyst, comprising the following steps:

[0007] (1) preparing a tungsten source solution, a ruthenium source solution, a cerium source solution and a soluble salt solution respectively;

[0008] (2) adding a tungsten source solution, a ruthenium source solution, a soluble salt solution, and a cerium source solution to a solvent in sequence and mixing them uniformly to prepare an electrodeposition solution;

[0009] (3) taking the electrodeposition solution in step (2) and performing electrochemical deposition to obtain a precursor;

[0010] (4) calcining the precursor obtained in step (3) at high temperature to obtain the product.

[0011] Preferably, the tungsten source in step (1) is selected from one or more of potassium tungstate, sodium tungstate, and ammonium tungstate.

[0012] Preferably, the ruthenium source in step (1) is selected from one or more of ruthenium chloride, ruthenium bromide, ruthenium sulfate, and ruthenium nitrate.

[0013] Preferably, the cerium source in step (1) is selected from one or more of cerium nitrate, cerium chloride, and cerium acetate.

[0014] Preferably, the soluble salt in step (1) is selected from one or more of potassium sulfate, sodium sulfate, sodium chloride, and potassium chloride; the soluble salt is used to improve the conductivity of the solution.

[0015] Preferably, the solvent in step (2) is selected from one or more of deionized water, ultrapure water, and distilled water.

[0016] Preferably, the molar ratio of cerium to tungsten in the electrodeposition solution of step (2) is 1:2-5; more preferably, the molar ratio of cerium to tungsten is 1:3-3.5.

[0017] Preferably, the molar ratio of cerium to ruthenium in the electrodeposition solution of step (2) is 1:3-6; more preferably, the molar ratio of cerium to tungsten is 1:3.8-4.2.

[0018] Preferably, the molar ratio of cerium to potassium in the electrodeposition solution of step (2) is 1:300-400; more preferably, the molar ratio of cerium to tungsten is 1:350-360.

[0019] Preferably, the electrochemical deposition in step (3) is performed using a three-electrode system, wherein the titanium foam substrate serves as the cathode working electrode, Pt serves as the counter electrode, and Ag / AgCl serves as the reference electrode.

[0020] Preferably, the current density of the electrochemical deposition in step (3) is -15 to -5 mA / cm 2 , time is 1-4h; more preferably, the current density of the electrochemical deposition is -12 to -8 mA / cm 2 , time is 1.5-2.5h.

[0021] Preferably, the high-temperature calcination in step (4) is carried out at a temperature of 450-700° C. and for a time of 3-10 h; more preferably, the high-temperature calcination is carried out at a temperature of 500-600° C. and for a time of 4-6 h.

[0022] Preferably, the high-temperature calcination in step (4) is carried out in an air atmosphere.

[0023] The second aspect of the present invention provides a cerium-tungsten co-doped ruthenium oxide catalyst prepared according to the above preparation method.

[0024] The third aspect of the present invention provides the use of the cerium-tungsten co-doped ruthenium oxide catalyst prepared according to the above preparation method in the preparation of hydrogen energy.

[0025] Preferably, the application is specifically the oxygen evolution reaction at the anode of water electrolysis.

[0026] The present invention has found through extensive research that non-stoichiometric cerium oxide (CeO x ) has unique redox properties, especially Ce 3+ / Ce 4+ The easy transformation of CeO makes it have a strong oxygen buffering capacity, so it has great potential in improving the filling of oxygen vacancies in the RuO2 catalyst lattice. x The application of CeO in regulating lattice oxygen activity and electronic structure has been widely studied, but its application in stabilizing LOM mechanism OER catalysts has not been fully explored. x The dual role of CeO: On the one hand, x It can activate the activity of lattice oxygen to promote its consumption, and on the other hand, it can also promote the replenishment of lattice oxygen, which makes how to maintain the balance between the two a major challenge. In order to overcome this problem, the present invention uses a catalyst (W-RuO2) with an AEM reaction mechanism as a bridge, and introduces Ce on this basis to achieve dynamic replenishment of lattice oxygen, thereby avoiding the CeO xThe poor selectivity problem in lattice oxygen replenishment was solved, and the stable replenishment and consumption balance of lattice oxygen in RuO2 catalyst was successfully achieved, maintaining the stable operation of LOM. x The promotion of the filling of lattice oxygen vacancies activates the LOM reaction under the W-RuO2 stable framework, thereby balancing the consumption and filling of lattice oxygen, which can achieve dual optimization of the stability and high activity of RuO2 in OER, and effectively overcomes the defects of simply using W doping to improve the stability of RuO2 at the expense of activity, and simply using Ce doping to activate RuO2 lattice oxygen at the expense of stability. At the same time, by precisely controlling the doping amount of Ce, the roughness of the RuO2 crystal structure surface can be regulated, and then its OER performance can be regulated, achieving a dynamic balance between lattice oxygen consumption and replenishment, making the OER reaction of the LOM mechanism run stably, breaking through the technical bottleneck that traditional activity and stability cannot be taken into account at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The morphology and element distribution of the (Ce W)-RuO2 catalyst prepared in Example 1.

[0028] Figure 2 This is the morphology of the RuO2 catalyst prepared in Comparative Example 1.

[0029] Figure 3 These are the stability test results of the catalysts in Example 1 and Comparative Examples 1-3.

[0030] Figure 4 The activity test results of the catalysts in Example 1 and Comparative Examples 1-3 are shown.

[0031] Figure 5 TMA + Effect on catalyst activity.

[0032] Figure 6 The effect of Ce content on the catalyst morphology.

[0033] Figure 7 The effect of Ce content on the OER performance of the catalyst.

[0034] Figure 8 Schematic diagram of the mechanism of action of the catalyst of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Example 1

[0037] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0038] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, 0.2 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0039] (2) K2WO4 solution, RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (K2WO4, RuCl3, K2SO4 and Ce(NO3)3) were 2.4mmol / L, 2.9mmol / L, 255mmol / L and 0.72mmol / L, respectively.

[0040] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0041] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a (CeW)-RuO2 catalyst.

[0042] Example 2

[0043] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0044] (1) Prepare 0.17 mol / L Na2WO4 solution, 0.053 mol / L Na2SO4 solution, 0.2 mol / L CeCl3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0045] (2) Na2WO4 solution, RuCl3 solution, Na2SO4 solution and CeCl3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (Na2WO4, RuCl3, Na2SO4 and CeCl3) were 2.4 mmol / L, 2.9 mmol / L, 255 mmol / L and 0.72 mmol / L, respectively.

[0046] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0047] (4) The precursor obtained in step (3) was placed in an air atmosphere at 500° C. and calcined for 6 h to obtain a (CeW)-RuO2 catalyst.

[0048] Example 3

[0049] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0050] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, 0.2 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0051] (2) K2WO4 solution, RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (K2WO4, RuCl3, K2SO4 and Ce(NO3)3) were 2.4mmol / L, 2.9mmol / L, 255mmol / L and 0.72mmol / L, respectively.

[0052] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -15 mA / cm 2 , time is 1h.

[0053] (4) The precursor obtained in step (3) was placed in an air atmosphere at 600° C. and calcined for 4 h to obtain a (CeW)-RuO2 catalyst.

[0054] Comparative Example 1

[0055] A ruthenium-based catalyst, the preparation method of which comprises the following steps:

[0056] (1) Prepare 0.053 mol / L K2SO4 solution and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0057] (2) RuCl3 solution and K2SO4 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final solute (RuCl3, K2SO4) concentrations were 2.9 mmol / L and 255 mmol / L, respectively.

[0058] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0059] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a RuO2 catalyst.

[0060] Comparative Example 2

[0061] A tungsten-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0062] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0063] (2) K2WO4 solution, RuCl3 solution and K2SO4 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the three solutes (K2WO4, RuCl3 and K2SO4) were 2.4 mmol / L, 2.9 mmol / L and 255 mmol / L, respectively.

[0064] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0065] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a W-RuO2 catalyst.

[0066] Comparative Example 3

[0067] A cerium-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0068] (1) Prepare 0.053 mol / L K2SO4 solution, 0.2 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0069] (2) RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the three solutes (RuCl3, K2SO4 and Ce(NO3)3) were 2.9 mmol / L, 255 mmol / L and 0.72 mmol / L, respectively.

[0070] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0071] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a Ce-RuO2 catalyst.

[0072] Comparative Example 4

[0073] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0074] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, 0.1 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0075] (2) K2WO4 solution, RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (K2WO4, RuCl3, K2SO4 and Ce(NO3)3) were 2.4mmol / L, 2.9mmol / L, 255mmol / L and 0.36mmol / L, respectively.

[0076] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0077] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a (0.5CeW)-RuO2 catalyst.

[0078] Comparative Example 5

[0079] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0080] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, 0.4 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0081] (2) K2WO4 solution, RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (K2WO4, RuCl3, K2SO4 and Ce(NO3)3) were 2.4mmol / L, 2.9mmol / L, 255mmol / L and 1.44mmol / L, respectively.

[0082] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0083] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a (2CeW)-RuO2 catalyst.

[0084] Comparative Example 6

[0085] A cerium-tungsten co-doped ruthenium oxide catalyst, the preparation method of which comprises the following steps:

[0086] (1) Prepare 0.17 mol / L K2WO4 solution, 0.053 mol / L K2SO4 solution, 0.8 mol / L Ce(NO3)3 solution, and 0.1 mol / L RuCl3 solution respectively; and add 2.42 mol / L HCl to the RuCl3 solution to completely dissolve the RuCl3.

[0087] (2) K2WO4 solution, RuCl3 solution, K2SO4 solution and Ce(NO3)3 solution were added to deionized water in sequence and mixed evenly to prepare an electrodeposition solution, so that the final concentrations of the four solutes (K2WO4, RuCl3, K2SO4 and Ce(NO3)3) were 2.4mmol / L, 2.9mmol / L, 255mmol / L and 2.88mmol / L, respectively.

[0088] (3) The electrochemical deposition of the electroplating solution in step (2) was performed using a three-electrode system to obtain a precursor; wherein the foamed titanium base was used as the cathode working electrode, Pt was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The electroplating current density was -10 mA / cm 2 , time is 2h.

[0089] (4) The precursor obtained in step (3) was placed in an air atmosphere at 550° C. and calcined for 5 h to obtain a (4CeW)-RuO2 catalyst.

[0090] Verification Example 1

[0091] The (Ce W)-RuO2 catalyst prepared in Example 1 and the RuO2 catalyst prepared in Comparative Example 1 were respectively taken to test their morphology and element distribution. The results are as follows: Figure 1-2 The results show that the RuO2 catalyst prepared in Comparative Example 1 is a layer of RuO2 spheres of uniform size tightly connected to form an electroplated layer. The composition and structure are relatively uniform, indicating that the electrodeposition process has good controllability (see Figure 1 ); In the co-doped (Ce W)-RuO2 catalyst prepared in Example 1, the surface of the RuO2 coating becomes rough due to doping, but the overall coating is still a dense and interconnected coating. Moreover, Ce and W are evenly distributed in the RuO2 coating, indicating that the doping elements are successfully introduced and well dispersed in the material. This uniform distribution helps to improve the stability and electrochemical activity of the catalyst (see Figure 2 ).

[0092] In order to verify that the present invention promotes the (Ce W)-RuO2 catalyst to perform OER reaction in the LOM mechanism, that is, to improve its stability without losing activity, the OER reaction stability and activity of the catalysts prepared in Example 1 and Comparative Examples 1-3 were tested. The test adopted a standard three-electrode system, with the working electrode being the catalyst, the counter electrode being the Pt electrode, and the reference electrode being the Ag / AgCl electrode. The results showed that the OER stability of the catalyst was indeed improved by W doping in Comparative Example 2 (see Figure 3 ), but at the expense of reduced activity ( Figure 4). In Example 1, the (Ce W)-RuO2 catalyst co-doped with Ce and W was improved in terms of stability and activity; and its improvement effect was significantly better than the strategy of suppressing lattice oxygen activity by only W doping.

[0093] Then, TMA was added to the electrolyte. + ([(CH3)4N] + ) and observed the activity changes of the catalysts (Example 1, Comparative Examples 1-3). Because the reaction process of the LOM mechanism produces superoxide (*O2 2- ) intermediates, and in the reaction process of the AEM mechanism, superoxide-like (*O2 - ) intermediate, where *O2 2- Intermediates can be combined with TMA + This chemical bonding inhibits the release of O2, leading to a significant decrease in OER activity, which does not occur in the AEM-OER process. Therefore, this strategy can be used to directly verify the OER reaction pathway, that is, the (Ce W)-RuO2 catalyst of the present invention undergoes OER reaction under the LOM mechanism.

[0094] The results are as follows Figure 5 The results show that when TMA is added to the electrolyte + After addition of CeW, the activity of the (CeW)-RuO2 catalyst decreased significantly, so it can be inferred that the catalyst undergoes OER reaction under the premise of LOM reaction pathway. This also shows that the co-doping strategy of Ce and W can effectively improve the activity and stability of RuO2 catalyst while maintaining the LOM pathway.

[0095] Furthermore, the morphology and catalytic performance of the catalysts prepared in Example 1 and Comparative Examples 4-6 were characterized. Figure 6 and Figure 7 As shown. The results show that with the increase of Ce content, the RuO2 catalyst gradually tends to be amorphous. Due to the poor crystallinity and more defects of amorphous RuO2, its lattice oxygen has higher activity and is more likely to participate in the oxygen evolution reaction (OER), thereby improving the catalytic activity. However, when the Ce content is too high, the catalyst activity decreases instead, which may be due to the decrease in RuO2 content and the decrease in mechanical stability caused by the highly amorphous structure. Therefore, the optimal Ce doping amount was obtained by regulating the morphology and performance, that is, the molar ratio of Ce to W is 1:2-5, preferably, the molar ratio of Ce to W is 1:3-3.5, and optimally, the molar ratio of Ce to W is 1:3.33.

[0096] The present invention has found through extensive research that non-stoichiometric cerium oxide (CeO x) has unique redox properties, especially Ce 3+ / Ce 4+ The easy transformation of CeO makes it have a strong oxygen buffering capacity, so it has great potential in improving the filling of oxygen vacancies in the RuO2 catalyst lattice. x The application of CeO in regulating lattice oxygen activity and electronic structure has been widely studied, but its application in stabilizing LOM mechanism OER catalysts has not been fully explored. x The dual role of CeO x It can activate the activity of lattice oxygen to promote its consumption, and on the other hand, it can also promote the replenishment of lattice oxygen, which makes how to maintain the balance between the two a major challenge.

[0097] In order to overcome this problem, the present invention adopts a catalyst (W-RuO2) of AEM reaction mechanism as a bridge, and introduces Ce on this basis to realize the dynamic replenishment of lattice oxygen, thereby avoiding the CeO x The poor selectivity problem in lattice oxygen replenishment was solved by successfully achieving a stable balance between lattice oxygen replenishment and consumption in RuO2 catalyst, maintaining stable LOM operation. The specific mechanism is as follows Figure 8 As shown in Figure 3, RuO2 (blue dots) suffers from rapid Ru dissolution during the LOM OER reaction because its lattice oxygen consumption rate is much greater than its filling rate. Although Ce's unique oxygen buffering capacity makes it potentially effective in improving lattice oxygen filling, directly doping Ce into RuO2 catalysts, i.e., Ce-RuO2 catalysts (green dots), is difficult to achieve a balance between lattice oxygen consumption and filling. This is because the requirement for "Δ1 filling" to be much greater than "Δ1 consumption" places high demands on the selectivity of Ce in promoting lattice oxygen filling, making this difficult to achieve. To this end, a W-doped W-RuO2 catalyst (purple dots) was employed as a bridge. Due to the suppressed lattice oxygen activity, this catalyst undergoes the OER reaction via the AEM mechanism, thus suppressing lattice oxygen consumption. Further Ce doping of the W-RuO2 catalyst yielded the (CeW)-RuO2 catalyst. It can be seen that simply achieving a "Δ2 filling" equal to the "Δ2 consumption" balances lattice oxygen consumption and filling, thus successfully stabilizing the RuO2 catalyst for the LOM OER reaction. Furthermore, the present invention also found that the Ce doping level significantly affects the microstructure, stability, and catalytic activity of the RuO2 catalyst. By precisely controlling the Ce doping level, the surface roughness of the RuO2 crystal structure can be adjusted, thereby regulating its OER performance.

[0098] The present invention utilizes the bridge effect of AEM-OER catalyst and CeO xThe promotion of the filling of lattice oxygen vacancies activates the LOM reaction under the W-RuO2 stable framework, thereby balancing the consumption and filling of lattice oxygen, which can achieve dual optimization of RuO2's stability and high activity in OER, effectively overcoming the defects of simply using W doping to improve RuO2 stability at the expense of activity, and simply using Ce doping to activate RuO2 lattice oxygen at the expense of stability, achieving a dynamic balance between lattice oxygen consumption and replenishment, making the OER reaction of the LOM mechanism run stably, and breaking through the technical bottleneck that traditional activity and stability cannot be taken into account at the same time.

[0099] The above detailed description of the analytical methods involved in the present invention provides a detailed introduction. It should be noted that the above description is intended solely to help those skilled in the art better understand the methods and concepts of the present invention, and is not intended to limit the relevant content. Without departing from the principles of the present invention, those skilled in the art may make appropriate adjustments or modifications to the present invention, and such adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A method for preparing a cerium-tungsten co-doped ruthenium oxide catalyst, characterized in that: The steps include: (1) preparing a tungsten source solution, a ruthenium source solution, a cerium source solution and a soluble salt solution respectively; (2) adding a tungsten source solution, a ruthenium source solution, a soluble salt solution, and a cerium source solution to a solvent in sequence and mixing them uniformly to prepare an electrodeposition solution; (3) taking the electrodeposition solution in step (2) and performing electrochemical deposition to obtain a precursor; (4) calcining the precursor obtained in step (3) at high temperature to obtain the product.

2. The preparation method according to claim 1, characterized in that The tungsten source in step (1) is selected from one or more of potassium tungstate, sodium tungstate, and ammonium tungstate.

3. The preparation method according to claim 1, characterized in that The ruthenium source in step (1) is selected from one or more of ruthenium chloride, ruthenium bromide, ruthenium sulfate, and ruthenium nitrate.

4. The preparation method according to claim 1, characterized in that The cerium source in step (1) is selected from one or more of cerium nitrate, cerium chloride, and cerium acetate.

5. The preparation method according to claim 1, characterized in that The soluble salt in step (1) is selected from one or more of potassium sulfate, sodium sulfate, sodium chloride and potassium chloride.

6. The preparation method according to claim 1, characterized in that The electrochemical deposition in step (3) is carried out using a three-electrode system, wherein the foamed titanium substrate serves as the cathode working electrode, Pt serves as the counter electrode, and Ag / AgCl serves as the reference electrode.

7. The preparation method according to claim 1, characterized in that The current density of the electrochemical deposition in step (3) is -15 to -5 mA / cm 2 , time is 1-4h.

8. The high temperature calcination in step (4) is carried out at a temperature of 450-700°C and for a time of 3-10 hours.

9. The cerium-tungsten co-doped ruthenium oxide catalyst prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the cerium-tungsten co-doped ruthenium oxide catalyst prepared according to the preparation method according to any one of claims 1 to 8 in hydrogen energy production.

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