Mixed metal oxide electrode and preparation method and application thereof

Abstract

The invention belongs to the technical field of electrode materials, and particularly relates to a mixed metal oxide electrode and a preparation method and application thereof. The mixed metal oxide electrode comprises a conductive substrate and a mixed metal oxide loaded on the conductive substrate, wherein the molecular formula of the mixed metal oxide is MxRu1-xO2; wherein M is respectively two or more of Ti, Sn, Sb, Nb, Zr, V, Co, Fe and Ni; x is the ratio of the mole number of all metals in M to the mole number of all metals in MxRu1-xO2, and x is 20-70%. According to the mixed metal oxide electrode, the use of noble metal Ir can be avoided, and the activity and selectivity of an electro-catalysis chloride ion oxidation reaction in a wide solution pH range (0-10) are improved.

Description

Technical Field

[0001] This invention belongs to the field of electrode material technology, specifically relating to a mixed metal oxide electrode, its preparation method, and its applications. Background Technology

[0002] Activated chlorine includes chlorine gas (Cl2), hypochlorous acid (HClO), sodium hypochlorite (NaClO), and other chlorine-containing compounds with strong oxidizing properties. These are widely used in disinfectant production, wastewater treatment, and tap water disinfection. Industrially, they are typically obtained through chloride ion oxidation reactions (e.g., chlorine evolution reactions). For a long time, new anode materials have been developed to improve the current efficiency and long-term stability of the anode during chloride ion oxidation. Currently, commercially available dimensionally stable anodes (DSA) still heavily rely on the use of a large amount (15% of the total metal molar weight) of the precious metal iridium (1300 yuan / gram) to improve electrode catalytic activity, and the addition of tantalum to the substrate to improve electrode stability, which significantly increases the cost of electrode fabrication. Ruthenium dioxide, due to its relatively low price (106 yuan / gram) and high electrocatalytic activity, shows great application potential, but it is unstable under long-term oxidation conditions, necessitating improvements in the selectivity and long-term stability of chloride ion oxidation.

[0003] This application is submitted in order to address the aforementioned issues. Summary of the Invention

[0004] The first aspect of this application provides a mixed metal oxide electrode, the mixed metal oxide electrode comprising a conductive substrate and a mixed metal oxide loaded on the conductive substrate, the mixed metal oxide having the molecular formula M x Ru 1-x O2;

[0005] Wherein, M is two or more of Ti, Sn, Sb, Nb, Zr, V, Co, Fe, and Ni;

[0006] x is the number of moles of all metals in M ​​and M x Ru 1-x The ratio of the number of moles of all metals in O2, x = 20-70%.

[0007] The above "multiple" refers to two or more types, such as three, four, five, six, seven, eight, or nine.

[0008] Preferably, the mixed metal oxide electrode has a mud-crack-like surface, which is composed of nanoparticles with a size of 5 to 100 nanometers.

[0009] Preferably, the metal elements in the mixed metal oxide are uniformly dispersed.

[0010] Preferably, the conductive substrate is a porous carbon material or a porous metal material.

[0011] The second aspect of this application provides a method for preparing the mixed metal oxide electrode described in the first aspect, the method comprising the following steps:

[0012] (1) Prepare alcohol solutions of different metals respectively;

[0013] The alcohol solutions of the different metals include ruthenium and M.

[0014] Wherein, M is two or more of Ti, Sn, Sb, Nb, Zr, V, Co, Fe, and Ni;

[0015] (2) Mix the alcohol solutions of different metals prepared in step (1) to obtain a mixed solution in which the different metals are evenly dispersed. The molar ratio of ruthenium and M in the mixed solution is 1-x:x, where x = 20% to 70%.

[0016] Then, a polymer with polydentate ligands is added to the mixed solution, and the mixture is heated and stirred to allow it to fully react with the solution to be coated.

[0017] (3) The coating solution obtained in step (2) is brushed onto the conductive substrate and heated to dry. This coating-heating and drying process is performed 1-4 times in total.

[0018] (4) The conductive substrate obtained in step (3) is calcined in air and then cooled to room temperature in air. This calcination-cooling process is performed 1-4 times in total.

[0019] (5) The porous conductive substrate obtained in step (4) is placed in a muffle furnace for calcination, allowing it to fully contact and react with air, and to tightly bond the porous conductive substrate and the catalyst on its surface. The substrate is then cooled to room temperature in the furnace to obtain a mixed metal oxide electrode.

[0020] Preferably, the polymer with polydentate ligands added in step (2) is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyethylene diamine and polyvinylpyrrolidone.

[0021] Preferably, in step (2), the ratio of the polymer with polydentate ligands to the total metal in the solution to be coated is (60-240 mg):(0.5-2 mmol).

[0022] Preferably, in step (2), the heating and stirring temperature is 50-90℃ and the time is 2-8h;

[0023] The drying temperature in step (3) is 50-90℃ and the drying time is 1-20 min.

[0024] The calcination temperature in step (4) is 400-600℃ and the calcination time is 1-20min.

[0025] The calcination temperature in step (5) is 400-600℃ and the calcination time is 0.5-3h.

[0026] The third aspect of this application provides the use of the mixed metal oxide electrode described in the first aspect for the electrocatalytic oxidation of chloride ions to produce active chlorine under different pH conditions.

[0027] Active chlorine includes: chlorine gas, hypochlorous acid, and hypochlorite ions. Hypochlorite ions are derived from, for example, sodium hypochlorite or potassium hypochlorite.

[0028] The fourth aspect of this application provides the use of the mixed metal oxide electrode described in the first aspect for improving the activity and selectivity of electrocatalytic chloride ion oxidation to active chlorine under different pH conditions.

[0029] Preferably, the different pH values ​​mentioned above fall within the range of 0 to 10. That is, the electrolyte type can be acidic, neutral, or alkaline.

[0030] According to the Hume-Rothery rule, when the atomic size difference of the components is less than 14-15%, it favors the formation of solid solutions with higher solubility (solubility limit); when it is greater than 15%, it is unfavorable for the formation of solid solutions. Modulating the electronic structure of electrocatalysts by doping with other elements of suitable size and electronegativity is a common and effective way to improve electrocatalytic performance. Therefore, this application develops a highly efficient and low-cost electrocatalytic chloride ion oxidation catalyst by doping ruthenium dioxide with relatively low-cost non-noble metal oxides.

[0031] The hybrid metal oxide electrode is prepared using a sol-gel method. This electrode belongs to the category of low-noble-metal hybrid oxide electrodes. In this electrode, the noble metal iridium is not used, and the amount of the relatively inexpensive noble metal ruthenium is reduced. This significantly reduces the preparation cost of the DSA electrode while exhibiting superior electrochemical activity and chlorination selectivity compared to commercial DSAs, along with good stability. Furthermore, the electrode preparation method is simple, enabling mass production and application.

[0032] Compared with the prior art, this application has the following advantages:

[0033] 1. This application discloses a high-performance hybrid metal oxide electrode. The inventors have discovered that doping ruthenium dioxide with metal elements has significant advantages in this electrode:

[0034] (1) In terms of activity, appropriate doping with metals such as Ti, Sn, Sb, Nb, Zr, V, Co, Fe, and Ni can adjust the electronic structure of oxygen active sites, which is beneficial to their adsorption of chlorine, thereby reducing the free energy of the rate-determining step and improving the catalytic activity of the electrode. However, too much or too little element doping will not achieve the desired effect: if the element doping is too low (i.e., x < 20%), the change in the performance of ruthenium dioxide electrode is not obvious, and its preparation cost is not significantly reduced, so its practical application value is not great; if the element doping is too high (i.e., x > 70%), the crystal structure of ruthenium dioxide is prone to large distortion, the electrode material will split, impurity phases will be generated, and the performance will rapidly degrade.

[0035] (2) Regarding stability, the reason why traditional ruthenium dioxide-based catalysts are unstable under long-term oxidation conditions is mainly because ruthenium dioxide is easily over-oxidized into soluble species and dissolved in the electrolyte at the oxidation potential. However, by incorporating non-noble metals into ruthenium dioxide nanomaterials, the covalent nature of the Ru-O bond is weakened due to the introduction of the dopant metal, resulting in ruthenium being in a lower valence state and suppressing its over-oxidation at the oxidation potential during the reaction process. This allows the electrode material to exhibit good stability when applied to the electrocatalytic chloride ion oxidation reaction. During the stability test, the galvanostatic polarization curve can still remain stable for a long time under high current density operating conditions. Moreover, in the preparation process, the highest valence compounds of doped metals such as Ti, Sn, and Sb are used as transition metal sources. The high temperature and high pressure liquid environment allows them to be fully oxidized, and their oxides have strong stability, thus playing a stable role in regulating the ruthenium sites in the electrolyte, thereby improving the stability of the electrode. Attached Figure Description

[0036] Figure 1 The Zr obtained in Examples 1, 3, 5, and 7 respectively 0.6 Sb 0.1 Ru 0.3 O2 electrode, Zr 0.6 V 0.1 Ru 0.3 O2 electrode, Sn 0.6 Nb 0.1 Ru 0.3 O2 electrode, Sn 0.6 Ti 0.1 Ru 0.3 SEM image of the O2 electrode.

[0037] Figure 2 It is Zr 0.6 Sb 0.1 Ru 0.3 Surface elemental distribution diagram of O2 electrode.

[0038] Figure 3 It is Zr 0.6 V 0.1 Ru 0.3 Surface elemental distribution diagram of O2 electrode.

[0039] Figure 4 It is Sn 0.6 Nb 0.1 Ru 0.3 Surface elemental distribution diagram of O2 electrode.

[0040] Figure 5 It is Sn 0.6 Ti 0.1 Ru 0.3 Surface elemental distribution diagram of O2 electrode.

[0041] Figure 6 It is Zr 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 TEM image of particles on the surface of the O2 electrode.

[0042] Figure 7 The nine curves A, B, C, D, E, F, G, H, and I represent the Zr curves in Example 1. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2 electrode, Ti 0.14 Sn 0.07 Sb 0.07Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.0 7Ni 0.07 Ru 0.3 Polarization curves of electrocatalytic chlorine production under acidic conditions using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0043] Figure 8 The nine curves A, B, C, D, E, F, G, H, and I represent the Zr curves in Example 1. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2 electrode, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.0 7Ni 0.07 Ru 0.3 Chlorine selectivity histograms for O2 electrode and commercial ruthenium-iridium DSA electrode.

[0044] Figure 9 The five curves A, B, C, D, and E are respectively obtained from Example 2 regarding Zr. 0.6 Sb 0.1 Ru 0.3 O2 electrode, Zr 0.1 Sb 0.1 Ru 0.8 O2 electrode, Zr 0.7 Sb 0.1 Ru 0.2 O2 electrode, Zr 0.05 Sb0.05 Ru 0.9 Polarization curves of electrocatalytic chlorine production using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0045] Figure 10 The five curves A, B, C, D, and E are respectively obtained from Example 3 for Zr. 0.6 V 0.1 Ru 0.3 O2 electrode, Zr 0.1 V 0.1 Ru 0.8 O2 electrode, Zr 0.7 V 0.1 Ru 0.2 O2 electrode, Zr 0.05 V 0.05 Ru 0.9 Polarization curves of electrocatalytic chlorine production using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0046] Figure 11 The five curves A, B, C, D, and E are respectively obtained from Sn in Example 4. 0.6 Nb 0.1 Ru 0.3 O2 electrode, Sn 0.1 Nb 0.1 Ru 0.8 O2 electrode, Sn 0.7 Nb 0.1 Ru 0.2 O2 electrode, Sn 0.05 Nb 0.05 Ru 0.9 Polarization curves of electrocatalytic chlorine production using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0047] Figure 12 The five curves A, B, C, D, and E are respectively obtained from Sn in Example 5. 0.6 Ti 0.1 Ru 0.3 O2 electrode, Sn 0.1 Ti 0.1 Ru 0.8 O2 electrode, Sn 0.7 Ti 0.1 Ru 0.2 O2 electrode, Sn 0.05 Ti 0.05 Ru 0.9 Polarization curves of electrocatalytic chlorine production using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0048] Figure 13 The five curves A, B, C, D, and E are obtained from the Zr curve in Example 6. 0.6 Sb 0.1Ru 0.3 O2 electrode, Zr 0.6 V 0.1 Ru 0.3 O2 electrode, Sn 0.6 Nb 0.1 Ru 0.3 O2 electrode, Sn 0.6 Ti 0.1 Ru 0.3 Stability test curves for electrocatalytic chlorine production using O2 electrode and commercial ruthenium-iridium DSA electrode.

[0049] Figure 14 The nine curves A, B, C, D, E, F, G, H, and I represent Zr. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2 electrode, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 Polarization curves of hypochlorous acid electrocatalytic production under neutral conditions using an O2 electrode and a commercial ruthenium-iridium DSA electrode.

[0050] Figure 15 The nine curves A, B, C, D, E, F, G, H, and I represent Zr. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2 electrode, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 Polarization curves of electrocatalytic hypochlorite production under alkaline conditions using an O2 electrode and a commercial ruthenium-iridium DSA electrode. Detailed Implementation

[0051] The present application will now be described in further detail with reference to the embodiments.

[0052] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product manual. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0053] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” to another element, it can be directly connected to the other element, or there may be intermediate elements. Furthermore, the term “connected” as used herein can include wireless connections.

[0054] In the description of this application, unless otherwise stated, "a plurality of" means two or more. The terms "inner," "upper," "lower," etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0055] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0057] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0058] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions. Unless otherwise specified, all steps of this application can be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0059] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0060] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B".

[0061] Example 1

[0062] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0063] This embodiment provides Zr x Sb y Ru 1-x-y The preparation method of the O2 electrode includes the following steps, which can be adjusted by those skilled in the art with reference to existing technology:

[0064] (1) Prepare alcohol solutions of the metals respectively.

[0065] (2) The alcohol solutions prepared in step (1) are mixed according to different molar ratios to obtain uniformly dispersed solutions; then a polymer with multidentate ligands is added to the solution, and the mixture is heated and stirred to allow it to react fully.

[0066] (3) The solution obtained in step (2) is uniformly brushed onto the porous conductive substrate and then heated and dried. In this embodiment, the porous conductive substrate is titanium felt. The coating-heating and drying process is performed a total of 3 times.

[0067] (4) The porous conductive substrate was then placed in a muffle furnace for calcination, allowing it to fully contact and react with air, and then cooled to room temperature in air. This calcination-cooling process was performed a total of 3 times.

[0068] (5) The porous conductive substrate was then placed in a muffle furnace for calcination, allowing it to fully contact and react with air, thus ensuring a tight bond between the porous conductive substrate and the catalyst on its surface. The substrate was then cooled to room temperature in the furnace to obtain Zr. x Sb y Ru 1-x-y O2 electrode. This embodiment specifically obtains Zr. 0.6 Sb 0.1 Ru 0.3 O2 electrode.

[0069] In step (1), the alcoholic solution of the metal is an alcoholic solution of ruthenium trichloride, zirconium butoxide, and antimony trichloride, each with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 0.5 mol / L. -1 .

[0070] The mixed solution mentioned in step (2) is an alcoholic solution of ruthenium trichloride, zirconium butoxide, and antimony trichloride; the total amount of metal in the mixed solution is 0.5-2 mmol, and in this example, it is 2 mmol. The molar ratio of ruthenium, zirconium, and antimony in the mixed solution is 3:6:1. The amount of polymer with polydentate ligands added is 60-240 mg, and in this example, 240 mg of polyvinyl alcohol is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 50℃ for 8 h.

[0071] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 90°C. The drying time is 1–20 min, and in this embodiment it is 1 min.

[0072] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 600℃. The calcination time is 1-20 min, and in this embodiment it is 1 min.

[0073] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 600℃. The calcination time is 0.5-3h, and in this embodiment it is 0.5h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 1 mg / cm³. -2 The load thickness is 1μm.

[0074] The electrode Zr obtained above 0.6 Sb 0.1 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0075] Comparative Example 1

[0076] The preparation method is the same as in Example 1, except that the molar ratio of ruthenium, zirconium, and antimony in the mixed solution is 2:7:1. The resulting electrode is Zr. 0.7 Sb 0.1 Ru 0.2 O2.

[0077] Example 2

[0078] The preparation method is the same as in Example 1, except that the molar ratio of zirconium, antimony, and ruthenium in the mixed solution is 1:1:8. Furthermore, the porous conductive substrate is a titanium mesh.

[0079] The electrode prepared is Zr 0.1 Sb 0.1 Ru 0.8 O2.

[0080] Comparative Example 2

[0081] The preparation method is the same as in Example 2, except that the molar ratio of zirconium, antimony, and ruthenium in the mixed solution is 5:5:90. The resulting electrode is Zr. 0.05 Sb 0.05 Ru 0.9 O2.

[0082] Example 3

[0083] This embodiment provides Zr x V y Ru 1-x-y The preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0084] In step (1), the alcoholic solution of the metal is an alcoholic solution of ruthenium trichloride, zirconium butoxide, and vanadium trichloride, with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 0.5 mol / L. -1 .

[0085] The mixed solution mentioned in step (2) is an alcoholic solution of ruthenium trichloride, zirconium butoxide, and vanadium trichloride; the total amount of metal in the mixed solution is 0.5-2 mmol, and in this embodiment, it is 2 mmol. The molar ratio of ruthenium, zirconium, and vanadium in the mixed solution is 3:6:1. The amount of polymer with multidentate ligands added is 60-240 mg, and in this embodiment, 240 mg of polyethylene glycol is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this embodiment, stirring is carried out at 80℃ for 4 h. The porous conductive substrate is carbon paper.

[0086] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 80°C. The drying time is 1–20 min, and in this embodiment it is 5 min.

[0087] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 500℃. The calcination time is 1-20 min, and in this embodiment it is 5 min.

[0088] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 500℃. The calcination time is 0.5-3h, and in this embodiment it is 1h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 4.2 mg / cm³. -2 The load thickness is 37μm.

[0089] The electrode Zr obtained above 0.6 V 0.1 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0090] Comparative Example 3

[0091] The preparation method is the same as in Example 3, except that the molar ratio of zirconium, vanadium, and ruthenium in the mixed solution is 7:1:2. The resulting electrode is Zr. 0.7 V 0.1 Ru 0.2 O2.

[0092] Example 4

[0093] The preparation method is the same as in Example 3, except that the molar ratios of zirconium, vanadium, and ruthenium in the mixed solution are 1:1:8. Furthermore, the porous conductive substrate is carbon cloth.

[0094] The electrode prepared is Zr 0.1 V 0.1 Ru 0.8 O2.

[0095] Comparative Example 4

[0096] The preparation method is the same as in Example 4, except that the molar ratio of zirconium, vanadium, and ruthenium in the mixed solution is 5:5:90. The resulting electrode is Zr. 0.05 V 0.05 Ru 0.9 O2.

[0097] Example 5

[0098] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0099] This embodiment provides Sn x Nb y Ru 1-x-y The preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0100] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of ruthenium trichloride, tin tetrachloride, and niobium pentachloride, each with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 0.5 mol / L. -1 .

[0101] The mixed solution mentioned in step (2) is an alcoholic solution of ruthenium trichloride, tin tetrachloride, and niobium pentachloride; the total amount of metal in the mixed solution is 2 mmol, and the molar ratio of ruthenium, tin, and niobium in the mixed solution is 3:6:1. The amount of polymer with polydentate ligands added is 60-240 mg, and in this example, 240 mg of polyethylene glycol is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 60℃ for 6 h.

[0102] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 60°C. The drying time is 1–20 min, and in this embodiment it is 10 min.

[0103] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 1-20 min, and in this embodiment it is 10 min.

[0104] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 0.5-3h, and in this embodiment it is 2h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 3.8 mg / cm³. -2 The load thickness is 35μm.

[0105] The electrode Sn obtained above 0.6 Nb 0.1 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0106] Comparative Example 5

[0107] The preparation method is the same as in Example 5, except that the molar ratio of tin, niobium, and ruthenium in the mixed solution is 7:1:2. The resulting electrode is Sn.0.7 Nb 0.1 Ru 0.2 O2.

[0108] Example 6

[0109] The preparation method described in Example 5 differs from that in Example 5 only in that the molar ratio of tin, niobium, and ruthenium in the mixed solution is 1:1:8. The resulting electrode is Sn. 0.1 Nb 0.1 Ru 0.8 O2.

[0110] Comparative Example 6

[0111] The preparation method is the same as in Example 5, except that the molar ratio of tin, niobium, and ruthenium in the mixed solution is 5:5:90. The resulting electrode is Sn. 0.05 Nb 0.05 Ru 0.9 O2.

[0112] Example 7

[0113] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0114] This embodiment provides Sn x Ti y Ru 1-x-y The preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0115] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of ruthenium trichloride, tin tetrachloride, and tetrabutyl titanate, with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 1 mol L. -1 .

[0116] The mixed solution mentioned in step (2) is an alcoholic solution of ruthenium trichloride, tin tetrachloride, and tetrabutyl titanate; the total amount of metal in the mixed solution is 0.5 mmol, and the molar ratio of ruthenium, tin, and titanium in the mixed solution is 3:6:1. The amount of polymer with polydentate ligands added is 60-240 mg; in this example, 60 mg of polyvinylpyrrolidone is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h; in this example, stirring is carried out at 90℃ for 2 h.

[0117] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 50°C. The drying time is 1–20 min, and in this embodiment it is 20 min.

[0118] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 400℃. The calcination time is 1-20 min, and in this embodiment it is 20 min.

[0119] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 400℃. The calcination time is 0.5-3h, and in this embodiment it is 3h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 20 mg / cm³. -2 The load thickness is 100μm.

[0120] The electrode Sn obtained above 0.6 Ti 0.1 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0121] Comparative Example 7

[0122] The preparation method described in Example 7 differs from that in Example 7 only in that the molar ratio of tin, titanium, and ruthenium in the mixed solution is 7:1:2. The resulting electrode is Sn. 0.7 Ti 0.1 Ru 0.2 O2.

[0123] Example 8

[0124] The preparation method described in Example 7 differs from that in Example 7 only in that the molar ratio of tin, titanium, and ruthenium in the mixed solution is 1:1:8. The resulting electrode is Sn. 0.1 Ti 0.1 Ru 0.8 O2.

[0125] Comparative Example 8

[0126] The preparation method is the same as in Example 8, except that the molar ratio of tin, titanium, and ruthenium in the mixed solution is 5:5:90. The resulting electrode is Sn. 0.05 Ti 0.05 Ru 0.9 O2.

[0127] Example 9

[0128] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0129] This embodiment provides Ti x Sn y Sb z Ru 1-x-y-zThe preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0130] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of tetrabutyl titanate, tin tetrachloride, antimony trichloride, and ruthenium trichloride, with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 1 mol L. -1 .

[0131] The mixed solution mentioned in step (2) is an alcoholic solution of tetrabutyl titanate, tin tetrachloride, antimony trichloride, and ruthenium trichloride; the total amount of metal in the mixed solution is 0.5 mmol, and the molar ratio of ruthenium, titanium, tin, and antimony in the mixed solution is 3:2:2:3. The amount of polymer with multidentate ligands added is 60-240 mg, and in this example, 120 mg of polyvinylpyrrolidone is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 80℃ for 2 h.

[0132] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 60°C. The drying time is 1–20 min, and in this embodiment it is 10 min.

[0133] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 1-20 min, and in this embodiment it is 10 min.

[0134] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 0.5-3h, and in this embodiment it is 2h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 15 mg / cm³. -2 The load thickness is 80μm.

[0135] The electrode Ti obtained above 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0136] Example 10

[0137] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0138] This embodiment provides Nb x Zr y V z Ru 1-x-y-zThe preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0139] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of niobium pentachloride, zirconium tetrachloride, vanadium trichloride, and ruthenium trichloride, with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 1 mol L. -1 .

[0140] The mixed solution mentioned in step (2) is an alcoholic solution of niobium pentachloride, zirconium tetrachloride, vanadium trichloride, and ruthenium trichloride; the total amount of metal in the mixed solution is 0.5 mmol, and the molar ratio of ruthenium, niobium, zirconium, and vanadium in the mixed solution is 3:2:2:3. The amount of polymer with polydentate ligands added is 60-240 mg, and in this example, 150 mg of polyvinylpyrrolidone is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 70℃ for 5 h.

[0141] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 70°C. The drying time is 1–20 min, and in this embodiment it is 10 min.

[0142] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 1-20 min, and in this embodiment it is 10 min.

[0143] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 0.5-3h, and in this embodiment it is 2h. The loading of mixed metal oxides on the conductive substrate surface is 1-20mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 12 mg / cm³. -2 The load thickness is 70μm.

[0144] The electrode Nb obtained above 0.2 Zr 0.2 V 0.3 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0145] Example 11

[0146] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0147] This embodiment provides Co x Fe y Ni z Ru 1-x-y-zThe preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0148] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of cobalt trichloride, ferric trichloride, nickel chloride, and ruthenium trichloride, with a concentration of 0.5 mol / L. -1 ~1mol L -1 In this embodiment, all values ​​are 1 mol L. -1 .

[0149] The mixed solution mentioned in step (2) is an alcoholic solution of cobalt trichloride, ferric trichloride, vanadium trichloride, and nickel chloride; the total amount of metal in the mixed solution is 0.5 mmol, and the molar ratio of ruthenium, niobium, zirconium, and vanadium in the mixed solution is 7:1:1:1. The amount of polymer with polydentate ligands added is 60-240 mg, and in this example, 150 mg of polyvinylpyrrolidone is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 80℃ for 5 h.

[0150] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 70°C. The drying time is 1–20 min, and in this embodiment it is 10 min.

[0151] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 1-20 min, and in this embodiment it is 10 min.

[0152] The temperature of the muffle furnace in step (5) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 0.5-3 hours, and in this embodiment it is 2 hours. Co x Fe y Ni z Ru 1-x-y-z In the O2 electrode, the loading of mixed metal oxides on the conductive substrate surface is 1-20 mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 12 mg / cm³. -2 The load thickness is 70μm.

[0153] The electrode Co obtained above 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2 can be used directly as a working electrode without further processing.

[0154] Example 12

[0155] Preparation of a low-noble metal mixed oxide electrode for electrocatalytic chloride ion oxidation.

[0156] This embodiment provides Tia Sn b Sb c Nb d Zr e V f Co g Fe h Ni i Ru j The preparation method of the O2 electrode includes the following steps, referring to the preparation method in Example 1.

[0157] The alcoholic solution of the metal mentioned in step (1) is an alcoholic solution of tetrabutyl titanate, tin tetrachloride, antimony trichloride, niobium pentachloride, zirconium tetrachloride, vanadium trichloride, cobalt trichloride, ferric chloride, nickel chloride, and ruthenium trichloride, with a concentration of 0.5 mol / L. -1 ~1mol / L -1 In this embodiment, all values ​​are 1 mol L. -1 .

[0158] The mixed solution mentioned in step (2) is an alcoholic solution of tetrabutyl titanate, tin tetrachloride, antimony trichloride, niobium pentachloride, zirconium tetrachloride, vanadium trichloride, cobalt trichloride, ferric chloride, nickel chloride, and ruthenium trichloride; the total amount of metal in the mixed solution is 0.5 mmol, and the molar ratio of titanium, tin, antimony, niobium, zirconium, vanadium, cobalt, iron, nickel, and ruthenium in the mixed solution is 14:7:7:7:7:7:7:7:7:30. The amount of polymer with multidentate ligands added is 60-240 mg, and in this example, 150 mg of polyvinylpyrrolidone is added. The heating and stirring temperature is 50-90℃, and the time is 2-8 h, and in this example, stirring is carried out at 80℃ for 4 h.

[0159] The drying temperature in step (3) is 50–90°C, and in this embodiment it is 70°C. The drying time is 1–20 min, and in this embodiment it is 10 min.

[0160] The calcination temperature in the muffle furnace in step (4) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 1-20 min, and in this embodiment it is 10 min.

[0161] The muffle furnace temperature in step (5) is 400-600℃, and in this embodiment it is 450℃. The calcination time is 0.5-3 hours, and in this embodiment it is 2 hours. The loading of mixed metal oxides on the conductive substrate surface is 1-20 mg / cm³. -2 The load thickness is 1-100 μm. In this embodiment, the load is 10 mg / cm³. -2 The load thickness is 60μm.

[0162] The electrode Ti obtained above 0.14 Sn 0.07 Sb0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 O2 can be used directly as a working electrode without further processing.

[0163] Morphological characteristics:

[0164] Morphological characterization of the low-noble metal mixed oxide electrode obtained above.

[0165] The electrodes obtained in Examples 1, 3, 5, and 7 were subjected to scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) tests. Figure 1 In the equation, a, b, c, and d represent Zr values ​​respectively. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 The SEM images of the O2 electrodes show that the surfaces of all four electrodes exhibit uniform mud-crack patterns, which is typical of sintered oxide electrodes. Figure 2 , 3 Zr, 4, and 5 respectively 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 The surface elemental distribution diagram of the O2 electrode shows that the metal elements in the prepared mixed metal oxide are uniformly dispersed.

[0166] For Zr respectively 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti0.1 Ru 0.3 The O2 electrode was subjected to ultrasonication and centrifugal drying in an alcohol solution to obtain its surface particles, which were then analyzed by transmission electron microscopy (TEM). The results are as follows: Figure 6 As shown, where a, b, c, and d are Zr values ​​respectively. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 The TEM image corresponding to the O2 electrode shows that the surface of the fabricated mixed metal oxide electrode is composed of nanoparticles with a size of 5 to 100 nanometers.

[0167] Application Example 1

[0168] Electrochemical performance and chlorine selectivity of the low-noble-metal mixed oxide electrode used for electrocatalytic chloride ion oxidation in hydrochloric acid.

[0169] The electrodes obtained in Examples 1, 3, 5, 7, 9, 10, 11, and 12 were subjected to performance and selectivity tests for electrocatalytic chlorine production under acidic conditions.

[0170] The testing method is as follows:

[0171] At room temperature, a two-chamber H-type electrolytic cell with a diaphragm was connected to an electrochemical workstation for testing. The diaphragm was a Nation 117 proton exchange membrane. Each chamber of the electrolytic cell had a capacity of 50 mL. An Ag / AgCl electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode. The prepared electrode and a commercial ruthenium-iridium DSA electrode were used as the working electrodes. 40 mL of 1 mol L⁻¹ solution was added to each side of the electrolytic cell. -1 A hydrochloric acid solution (pH=0) was used as the electrolyte. The performance of the electrocatalytic chlorine production was tested using a linear sweep voltammetry system. The chlorine content obtained from the electrolysis of the hydrochloric acid solution was measured by iodometric titration and compared with the theoretical value to obtain the chlorine selectivity.

[0172] Figure 7 The nine curves A, B, C, D, E, F, G, H, and I represent Zr... 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 Polarization curves of the O2 electrode and the commercial ruthenium-iridium DSA electrode are shown. It can be seen that the overpotentials at a current density of 10 mA / cm² are 43 mV, 50 mV, 45 mV, 53 mV, 51 mV, 48 mV, 55 mV, and 56 mV, respectively, all lower than the 60 mV of the commercial ruthenium-iridium DSA electrode. This indicates that the electrodes obtained in Examples 1, 3, 5, 7, 9, 10, 11, and 12 all exhibit better electrochemical activity than the commercial ruthenium-iridium DSA electrode.

[0173] Figure 8 A, B, C, D, E, F, G, H, and I represent Zr... 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 Chlorine selectivity histograms for O2 electrode and commercial ruthenium-iridium DSA electrode, where Zr 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 The selectivity of the O2 electrode for chlorine production was 94.0%, 93.3%, 92.4%, 93.7%, 93.6%, 90.6%, 89.3%, and 88.7%, respectively, all higher than the 87.4% of the commercial ruthenium-iridium DSA electrode. This indicates that the electrodes obtained in Examples 1, 3, 5, 7, 9, 10, 11, and 12 all have higher chlorine selectivity than the commercial ruthenium-iridium DSA electrode.

[0174] The above tests fully demonstrate that the low-noble metal mixed oxide electrode obtained by the sol-gel method has better electrochemical performance and higher chlorine selectivity than the commercial ruthenium-iridium DSA electrode.

[0175] Application Example 2

[0176] The electrodes obtained in Examples 1, 2, Comparative Example 1, and 2, as well as the commercial ruthenium-iridium DSA electrode, were subjected to electrocatalytic chlorine production performance tests, using the same methods as in Application Example 1.

[0177] The obtained polarization curves are as follows Figure 9 As shown, curves A, B, C, D, and E represent the Zr values ​​obtained in Example 1. 0.6 Sb 0.1 Ru 0.3 O2 electrode, Zr obtained in Example 2 0.1 Sb 0.1 Ru 0.8 O2 electrode, Zr obtained from Comparative Example 1 0.7 Sb 0.1 Ru 0.2 O2 electrode, Zr obtained from Comparative Example 2 0.05 Sb 0.05 Ru 0.9 Polarization curves of O2 electrode and commercial ruthenium-iridium DSA electrode.

[0178] It can be seen that the performance of the electrodes obtained in Examples 1 and 2 in producing chlorine gas by electrocatalysis is better than that of the commercial ruthenium-iridium DSA electrode.

[0179] The electrocatalytic chlorine production performance of the electrodes obtained in Comparative Examples 1 and 2 was significantly worse than that of the electrodes obtained in Examples 1 and 2 and the commercial ruthenium-iridium DSA electrode. At a current density of 10 mA / cm², the overpotentials were 84 mV and 65 mV, respectively, which were much greater than those of the electrodes obtained in Examples 1 and 2 (overpotentials of 43 mV and 52 mV) and the commercial ruthenium-iridium DSA electrode (overpotential of 60 mV).

[0180] Application Example 3

[0181] The electrodes obtained in Examples 3, 4, Comparative Examples 3 and 4, as well as the commercial ruthenium-iridium DSA electrode, were subjected to electrocatalytic chlorine production performance tests, using the same methods as in Application Example 1.

[0182] The obtained polarization curves are as follows Figure 10 As shown, curves A, B, C, D, and E represent the Zr values ​​obtained in Example 3. 0.6 Sb 0.1 Ru 0.3 O2 electrode, Zr obtained in Example 4 0.1 V 0.1 Ru 0.8 O2 electrode, Zr obtained from Comparative Example 3 0.7 V 0.1 Ru 0.2 O2 electrode, Zr obtained from Comparative Example 4 0.05 V 0.05 Ru 0.9Polarization curves of O2 electrode and commercial ruthenium-iridium DSA electrode.

[0183] It can be seen that the performance of the electrodes obtained in Examples 3 and 4 in producing chlorine gas by electrocatalysis is better than that of commercial ruthenium-iridium DSA electrodes.

[0184] The electrocatalytic chlorine production performance of the electrodes obtained in Comparative Examples 3 and 4 was significantly worse than that of the electrodes obtained in Examples 3 and 4 and the commercial ruthenium-iridium DSA electrode. At a current density of 10 mA / cm², the overpotentials were 108 mV and 76 mV, respectively, which were much greater than those of the electrodes obtained in Examples 3 and 4 (overpotentials of 50 mV and 49 mV) and the commercial ruthenium-iridium DSA electrode (overpotential of 60 mV).

[0185] Application Example 4

[0186] The electrodes obtained in Examples 5, 6, Comparative Examples 5 and 6, as well as the commercial ruthenium-iridium DSA electrode, were subjected to electrocatalytic chlorine production performance tests, using the same methods as in Application Example 1.

[0187] The obtained polarization curves are as follows Figure 11 As shown, curves A, B, C, D, and E represent the Sn obtained in Example 5. 0.6 Nb 0.1 Ru 0.3 O2 electrode, Sn obtained in Example 6 0.1 Nb 0.1 Ru 0.8 O2 electrode, Sn obtained from Comparative Example 5 0.7 Nb 0.1 Ru 0.2 O2 electrode, Sn obtained from Comparative Example 6 0.05 Nb 0.05 Ru 0.9 Polarization curves of O2 electrode and commercial ruthenium-iridium DSA electrode.

[0188] It can be seen that the performance of the electrodes obtained in Examples 5 and 6 in electrocatalytic chlorine production is better than that of commercial ruthenium-iridium DSA electrodes.

[0189] The electrocatalytic chlorine production performance of the electrodes obtained in Comparative Examples 5 and 6 was significantly worse than that of the electrodes obtained in Examples 5 and 6 and the commercial ruthenium-iridium DSA electrode. The overpotentials at a current density of 10 mA / cm² were 90 mV and 63 mV, respectively, which were much greater than those of the electrodes obtained in Examples 5 and 6 (45 mV and 48 mV) and the commercial ruthenium-iridium DSA electrode (60 mV).

[0190] Application Example 5

[0191] The electrodes obtained in Examples 7, 8, Comparative Examples 7 and 8, as well as the commercial ruthenium-iridium DSA electrode, were subjected to electrocatalytic chlorine production performance tests, using the same methods as in Application Example 1.

[0192] The obtained polarization curves are as follows Figure 12 As shown, curves A, B, C, D, and E represent the Sn obtained in Example 7. 0.6 Ti 0.1 Ru 0.3 O2 electrode, Sn obtained in Example 8 0.1 Ti 0.1 Ru 0.8 O2 electrode, Sn obtained from Comparative Example 7 0.7 Ti 0.1 Ru 0.2 O2 electrode, Sn obtained from Comparative Example 8 0.05 Ti 0.05 Ru 0.9 Polarization curves of O2 electrode and commercial ruthenium-iridium DSA electrode.

[0193] It can be seen that the performance of the electrodes obtained in Examples 7 and 8 in producing chlorine gas by electrocatalysis is better than that of commercial ruthenium-iridium DSA electrodes.

[0194] The electrocatalytic chlorine production performance of the electrodes obtained in Comparative Examples 7 and 8 was significantly worse than that of the electrodes obtained in Examples 7 and 8 and the commercial ruthenium-iridium DSA electrode. The overpotentials at a current density of 10 mA / cm² were 106 mV and 67 mV, respectively, which were much greater than those of the electrodes obtained in Examples 7 and 8 (53 mV and 54 mV) and the commercial ruthenium-iridium DSA electrode (60 mV).

[0195] As can be seen from application examples 2-5, too much or too little element doping does not achieve the desired effect: with less element doping (i.e., x < 20%), the change in the performance of the ruthenium dioxide electrode is not obvious, and its preparation cost is not significantly reduced, so its practical application value is not great; with more element doping (i.e., x > 70%), due to the excessive proportion of doped metal, the original crystal structure of ruthenium dioxide is greatly distorted, which leads to changes in the electrode structure and a sharp decline in electrode performance, which is lower than that of commercial ruthenium-iridium DSA electrodes.

[0196] Application Example 6

[0197] Electrochemical stability test of a low-noble-metal mixed oxide electrode used for electrocatalytic chloride ion oxidation.

[0198] The stability of the electrodes obtained in Examples 1, 3, 5, and 7 for electrocatalytic chlorine production was tested.

[0199] The testing method is as follows:

[0200] At room temperature, a two-chamber H-type electrolytic cell with a diaphragm was connected to an electrochemical workstation for testing. The diaphragm was a Nation 117 proton exchange membrane. Each chamber of the electrolytic cell had a capacity of 50 mL. An Ag / AgCl electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode. The prepared electrode and a commercial ruthenium-iridium DSA electrode were used as the working electrodes. 40 mL of 1 mol L⁻¹ solution was added to each side of the electrolytic cell. -1 A hydrochloric acid solution was used as the electrolyte and replenished periodically. The stability of the electrocatalytic chlorine production was tested using a constant current testing system.

[0201] Figure 13 A, B, C, D, and E represent Zr, respectively. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 The stability test results of the electrocatalytic chlorine production of the O2 electrode and the commercial ruthenium-iridium DSA electrode show that the electrodes obtained in Examples 1, 3, 5, and 7 require voltages of 1.44, 1.45, 1.45, and 1.47 volts (relative to the standard hydrogen electrode) to reach the same current density (100 mA / cm²), respectively. These voltages are lower than those of the commercial ruthenium-iridium DSA electrode (1.49 volts, relative to the standard hydrogen electrode). All of them can operate stably for 500 hours at a current density of 100 mA / cm² without a significant increase in voltage.

[0202] This indicates that the low-noble metal mixed oxide electrode obtained by the sol-gel method has excellent electrochemical stability comparable to that of commercial ruthenium-iridium DSA electrodes.

[0203] Application Example 7

[0204] Electrochemical performance test of low-noble metal mixed oxide electrode used for electrocatalytic chloride ion oxidation in neutral saline solution.

[0205] The electrodes obtained in Examples 1, 3, 5, 7, 9, 10, 11, and 12, and a commercial ruthenium-iridium DSA electrode were tested for their electrocatalytic production of hypochlorous acid under neutral conditions.

[0206] The test method is the same as in Application Example 1, except that the electrolyte is 1 mol L. -1 A sodium chloride solution (pH=7) was used as the electrolyte.

[0207] Figure 14A, B, C, D, E, F, G, H, and I represent Zr... 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru 0.3 The polarization curves of the O2 electrode and the commercial ruthenium-iridium DSA electrode in neutral electrolyte for the electrocatalytic production of hypochlorous acid show that Zr 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.0 7Ru 0.3 The O2 electrode exhibits superior peak potential and current growth rate compared to commercial ruthenium-iridium DSA electrodes.

[0208] Application Example 8

[0209] Electrochemical performance test of a low-noble-metal mixed oxide electrode used for electrocatalytic chloride ion oxidation in alkaline brine.

[0210] The electrodes obtained in Examples 1, 3, 5, 7, 9, 10, 11, and 12, and a commercial ruthenium-iridium DSA electrode were tested for their electrocatalytic production of hypochlorite under alkaline conditions.

[0211] The test method is the same as in Application Example 1, except that the electrolyte is 1 mol L. -1 A potassium chloride solution (adjusted to pH=10 with potassium hydroxide) was used as the electrolyte.

[0212] Figure 15 A, B, C, D, E, F, G, H, and I represent Zr... 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.07 Ru0.3 The polarization curves of the O2 electrode and the commercial ruthenium-iridium DSA electrode in alkaline electrolyte for the electrocatalytic production of hypochlorite can be seen. 0.6 Sb 0.1 Ru 0.3 O2, Zr 0.6 V 0.1 Ru 0.3 O2, Sn 0.6 Nb 0.1 Ru 0.3 O2, Sn 0.6 Ti 0.1 Ru 0.3 O2, Ti 0.2 Sn 0.2 Sb 0.3 Ru 0.3 O2, Nb 0.2 Zr 0.2 V 0.3 Ru 0.3 O2, Co 0.1 Fe 0.1 Ni 0.1 Ru 0.7 O2, Ti 0.14 Sn 0.07 Sb 0.07 Nb 0.07 Zr 0.07 V 0.07 Co 0.07 Fe 0.07 Ni 0.0 7Ru 0.3 The O2 electrode exhibits superior peak potential and current growth rate compared to commercial ruthenium-iridium DSA electrodes.

[0213] As can be seen from Application Examples 1, 7 and 8, the low-noble metal mixed oxide electrode obtained by the sol-gel method exhibits better electrochemical performance than the commercial ruthenium-iridium DSA electrode in chloride-containing solutions under different pH conditions (0-10).

Claims

1. A hybrid metal oxide electrode, characterized in that, The hybrid metal oxide electrode comprises a conductive substrate and a hybrid metal oxide loaded on the conductive substrate, wherein the molecular formula of the hybrid metal oxide is M. x Ru 1-x O2; Wherein, M is two or more of Ti, Sn, Sb, Nb, Zr, V, Co, Fe, and Ni; x is the number of moles of all metals in M ​​and M x Ru 1-x The ratio of the number of moles of all metals in O2, x = 20-70%.

2. The mixed metal oxide electrode according to claim 1, characterized in that, The hybrid metal oxide electrode has a mud-crack-like surface, which is composed of nanoparticles with a size of 5 to 100 nanometers.

3. The mixed metal oxide electrode according to claim 1, characterized in that, The metal elements in the mixed metal oxide are uniformly dispersed.

4. The mixed metal oxide electrode according to claim 1, characterized in that, The conductive substrate is a porous carbon material or a porous metal material.

5. The method for preparing the mixed metal oxide electrode according to claim 1, characterized in that, The preparation method includes the following steps: (1) Prepare alcohol solutions of different metals respectively; The alcohol solutions of the different metals include ruthenium and Mg. Wherein, M is two or more of Ti, Sn, Sb, Nb, Zr, V, Co, Fe, and Ni; (2) Mix the alcohol solutions of different metals prepared in step (1) to obtain a mixed solution in which the different metals are evenly dispersed. The molar ratio of ruthenium to M in the mixed solution is (1-x):x, where x = 20% to 70%. Then, a polymer with polydentate ligands is added to the mixed solution, and the mixture is heated and stirred to allow it to fully react with the solution to be coated. (3) The coating solution obtained in step (2) is brushed onto the conductive substrate and heated to dry. This coating-heating and drying process is performed 1-4 times in total. (4) The conductive substrate obtained in step (3) is calcined in air and then cooled to room temperature in air. This calcination-cooling process is performed 1-4 times in total. (5) The porous conductive substrate obtained in step (4) is placed in a muffle furnace for calcination, allowing it to fully contact and react with air, and to tightly bond the porous conductive substrate and the catalyst on its surface. The substrate is then cooled to room temperature in the furnace to obtain a mixed metal oxide electrode.

6. The method for preparing a mixed metal oxide electrode according to claim 5, characterized in that, The polymer with polydentate ligands added in step (2) is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyethylene diamine and polyvinylpyrrolidone.

7. The method for preparing a mixed metal oxide electrode according to claim 5, characterized in that, In step (2), the ratio of the polymer with polydentate ligands to the total metal in the solution to be coated is (60-240 mg): (0.5-2 mmol).

8. The method for preparing a mixed metal oxide electrode according to claim 5, characterized in that, In step (2), the heating and stirring temperature is 50-90℃ and the time is 2-8h; The drying temperature in step (3) is 50-90℃ and the drying time is 1-20 min; The calcination temperature in step (4) is 400-600℃ and the calcination time is 1-20 min; The calcination temperature in step (5) is 400-600℃ and the calcination time is 0.5-3h.

9. The use of the mixed metal oxide electrode of claim 1 for electrocatalytic oxidation of chloride ions to produce active chlorine under different pH conditions.

10. The use of the mixed metal oxide electrode of claim 1 for improving the activity and selectivity of electrocatalytic chloride ion oxidation to produce active chlorine under different pH conditions.

Images