Transition metal or rare earth element doped ruthenium dioxide catalyst, preparation method and acidic electrolyzed water application of transition metal or rare earth element doped ruthenium dioxide catalyst

Abstract

The invention belongs to the technical field of acidic electrolyzed water, and discloses a transition metal or rare earth element doped ruthenium dioxide catalyst, a preparation method and application of the transition metal or rare earth element doped ruthenium dioxide catalyst in acidic electrolyzed water, the preparation method comprises the following steps: weighing ruthenium metal salt, dissolving the ruthenium metal salt in an acidic aqueous solution, and carrying out mechanical stirring at room temperature to obtain a mixed solution A; adding transition metal or rare earth element salt into the mixed solution A, and mechanically stirring at room temperature to obtain a mixed solution B; adding a carbon template for adsorbing metal ions in the solution into the mixed solution B, ultrasonically dispersing uniformly, and mechanically stirring at room temperature to obtain a mixed turbid liquid C; placing the mixed turbid liquid C on a heating plate for high-temperature mechanical stirring so as to remove moisture in the turbid liquid, and fully grinding and evaporating the obtained sample; and taking a proper amount of the ground sample, and carrying out air calcination in a muffle furnace, wherein the calcination is used for decomposing the carbon template and oxidizing metal ions to obtain the transition metal or rare earth element doped ruthenium dioxide nanoparticles.

Description

Technical Field

[0001] The present invention belongs to the technical field of acidic water electrolysis, and specifically relates to the preparation of a transition metal or rare earth element doped ruthenium dioxide catalyst with fine particles and uniform size and its application in acidic water electrolysis, and provides a method for preparing an acidic water electrolysis catalyst with simple process, lower cost than commercial iridium oxide catalyst, excellent activity and stability. Background Art

[0002] Hydrogen energy is widely regarded as the ideal "ultimate renewable energy" because of its energy density, which is about three times higher than that of fossil fuels, and because it does not produce greenhouse gas emissions such as carbon dioxide during use. Although hydrogen energy has great potential, the current production of hydrogen mainly relies on the conversion of fossil fuels, which severely limits the potential of hydrogen energy as a clean energy source. In order to develop clean and sustainable hydrogen production technology, water electrolysis hydrogen production technology is particularly critical. At present, water electrolysis technology mainly includes four types: alkaline electrolysis, proton exchange membrane (PEM) electrolysis, anion exchange membrane (AEM) electrolysis, and solid oxide electrolysis. Among them, PEM water electrolysis technology has attracted much attention due to its advantages such as high current density, high-purity hydrogen production capacity, fast response speed, and adaptability to the volatility of renewable energy. Although its initial investment cost of equipment is higher than that of alkaline water hydrogen production, due to its low maintenance cost and long service life, the full life cycle cost can be on par with alkaline water hydrogen production. In addition, PEM technology has strong adaptability to the volatility and intermittency of green electricity such as wind power and photovoltaics, and can make greater use of the economic benefits brought by green electricity. At the same time, its hydrogen production has high purity and few impurities, making it the best choice for the market demanding high-quality hydrogen. However, in the process of water electrolysis using PEM technology, the high overpotential in the oxygen evolution reaction (OER) is a major technical bottleneck, which not only reduces the overall efficiency of the system but also increases the operating cost. Therefore, reducing the energy loss in the OER process has become the key to improving the efficiency of hydrogen production from PEM water electrolysis and reducing costs.

[0003] Due to the presence of strong acid and strong oxidizing environment on the anode side, the requirements for catalysts are more stringent. Therefore, the optimization of catalyst performance and the reduction of energy consumption are important research topics to promote the large-scale application of PEM technology. 2 ) is the most commonly used commercial catalyst for OER due to its excellent catalytic activity and stability. 2 The scarce and expensive resources pose an economic barrier to its widespread application. 2 ) also belongs to the category of precious metals, but it has more abundant reserves and relatively lower costs, and is more active in OER. 2As an alternative catalyst, it has significant advantages in cost and catalytic activity, but its stability in acidic environment during OER is still a major challenge. Specifically, under high potential conditions, RuO 2 It is easy to dissolve, resulting in the loss of catalytic active centers, which in turn affects its long-term stability and durability. The degradation of active sites can be aggravated by the following two mechanisms: one is the lattice oxygen mediated mechanism (LOM), in which the oxygen vacancies formed make the oxygen anions unstable; the other is that under high overpotential, Ru atoms may be over-oxidized to form soluble RuO 4 , thus inducing the demetallation of the active sites. These two mechanisms interact with each other and accelerate the deactivation process of Ru-based catalysts. 2 Although it has potential advantages over iridium dioxide in terms of cost control and catalytic efficiency, how to enhance its stability under acidic conditions remains a key issue that needs to be addressed. Future research needs to be devoted to overcoming this obstacle to promote the advancement and application of PEM water electrolysis technology.

[0004] Some studies have successfully improved RuO by strengthening the Ru-O bond through surface heat treatment. 2 Stability and activity of nanoparticles. In recent years, in order to regulate the local electronic structure and bonding environment of materials, doping with heteroatoms (including transition metals and rare earth elements) has become an effective means to improve catalytic performance. 2 The introduction of monodispersed low-concentration metal (M) doping sites in the catalyst can not only maintain its original high activity, but also further optimize the local electronic structure of the catalyst surface. This regulation effectively improves the adsorption energy between the active sites and oxygen-containing intermediates, reduces the reaction energy barrier of the rate-limiting step, and thus improves the reaction rate and overall catalytic activity. Specifically, heteroatom doping can change the charge distribution of the active sites, making it easier to form a weak but stable bond with the reaction intermediates, thereby accelerating the reaction rate. In addition, the doping elements significantly reduce the covalency of the Ru-O bond by regulating the overlap between the Ru 4d orbital and the O 2p orbital, thereby effectively inhibiting the LOM path. At the same time, the formation of the Ru-OM structure can effectively inhibit the dissolution of Ru atoms, reduce the formation of peroxides, avoid catalyst deactivation, and significantly improve the structural stability and long-term operating performance of the catalyst, so that it exhibits excellent stability and persistent activity in the efficient oxygen evolution reaction. In summary, the catalyst design based on transition metal or rare earth element doped ruthenium dioxide is an attractive strategy for the development of highly active and long-stable PEM water electrolysis anode catalysts in acidic environments. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a transition metal or rare earth element doped ruthenium dioxide catalyst with fine particles and uniform size and its acidic water electrolysis application. The preparation process we proposed is simple, easy to operate, and highly repeatable; the transition metal or rare earth element doped ruthenium dioxide nanoparticle catalyst has fine particles and uniform size distribution; it is made into a slurry and coated on carbon paper for use as an anode for acidic water electrolysis hydrogen production, which has excellent energy catalytic application prospects.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A transition metal or rare earth element doped ruthenium dioxide catalyst is provided. The transition metal or rare earth element doped ruthenium dioxide catalyst is nanoparticles of uniform size, with a particle size between 0.5-200nm, and the transition metal or rare earth element is doped into the ruthenium dioxide lattice.

[0008] The preparation method of a transition metal or rare earth element doped ruthenium dioxide catalyst comprises the following steps:

[0009] (1) weighing a ruthenium metal salt and dissolving it in an acidic aqueous solution, and mechanically stirring it at room temperature to obtain a mixed solution A;

[0010] (2) adding a transition metal or rare earth element salt to the mixed solution A, and mechanically stirring the mixture at room temperature to obtain a mixed solution B;

[0011] (3) adding a carbon template for adsorbing metal ions in the solution to the mixed solution B, uniformly dispersing the mixture through ultrasonication, and then mechanically stirring the mixture at room temperature to obtain a mixed suspension C;

[0012] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring to remove water from the suspension and fully grind the evaporated sample;

[0013] (5) Taking an appropriate amount of the ground sample and calcining it in air in a muffle furnace, wherein the calcination is used to decompose the carbon template and oxidize the metal ions to obtain transition metal or rare earth element doped ruthenium dioxide nanoparticles.

[0014] Furthermore, in step (1), the ruthenium source is ruthenium chloride and its hydrate, ruthenium acetylacetonate and its hydrate or ruthenium nitrate and its hydrate, with a purity of 80.0 to 99.99% and a mass of 10 to 1000 mg; the acidic solution is nitric acid, hydrochloric acid, sulfuric acid or hydrofluoric acid, with a molar concentration of 0 to 4 M, a volume of 10 to 500 mL, a stirring speed of 500 to 2000 r / min, and a stirring time of 20 to 180 min.

[0015] Furthermore, in step (2), the doped transition metals and rare earth elements are Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ta, W, Re, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; when the Sc element is doped, the scandium source is scandium chloride and its hydrate or scandium nitrate and its hydrate, the scandium source has a purity of 80.0 to 99.99% and a mass of 5 to 100 mg; when the Ti element is doped, the titanium source is titanium chloride and its hydrate or titanium nitrate and its hydrate, the titanium source has a purity of 80.0 to 99.99% and a mass of 5 to 100 mg; when the V element is doped, the vanadium source is vanadium chloride and its hydrate , vanadium nitrate and hydrates thereof, ammonium vanadate and hydrates thereof or sodium vanadate and hydrates thereof, the vanadium source having a purity of 80.0-99.99% and a mass of 5-100 mg; when doped with Cr element, the chromium source is chromium chloride and hydrates thereof or chromium nitrate and hydrates thereof, the chromium source having a purity of 80.0-99.99% and a mass of 5-100 mg; when doped with Mn element, the manganese source is manganese chloride and hydrates thereof, manganese nitrate and hydrates thereof, the manganese source having a purity of 80.0-99.99% and a mass of 5-100 mg; when doped with Co element, the cobalt source is cobalt chloride and hydrates thereof or cobalt nitrate and hydrates thereof, the cobalt source having a purity of 80.0-99.99% and a mass of 5-100 mg; when doped with Ni element, the nickel source is nickel chloride and hydrates thereof, nickel nitrate and Its hydrate, the nickel source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Cu element, the copper source is copper chloride and its hydrate or copper nitrate and its hydrate, the copper source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Zn element, the zinc source is zinc chloride and its hydrate or zinc nitrate and its hydrate, the zinc source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Y element, the yttrium source is yttrium chloride and its hydrate or yttrium nitrate and its hydrate, the yttrium source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Zr element, the zirconium source is zirconium chloride and its hydrate or zirconium nitrate and its hydrate, the zirconium source purity is 80.0-99.99%, the mass is When doped with Nb element, the niobium source is sodium niobate and its hydrate, ammonium niobate and its hydrate or ammonium niobate oxalate and its hydrate, the purity of the niobium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Mo element, the molybdenum source is sodium molybdate and its hydrate, ammonium molybdate and its hydrate or molybdenum chloride and its hydrate, the purity of the niobium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Ta element, the tantalum source is sodium tantalate and its hydrate or ammonium tantalate and its hydrate, the purity of the tantalum source is 80.0-99.99%, and the mass is 5-100 mg; when doped with W element, the tungsten source is sodium tungstate and its hydrate, tungsten tantalate and its hydrate or tungsten chloride and its hydrate, the purity of the tungsten source is 80.0-99.99%, with a mass of 5 to 100 mg; when doped with Re element, the rhenium source is sodium rhenate and its hydrate, tungsten rhenate and its hydrate or rhenium chloride and its hydrate, the purity of the rhenium source is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with La element, the lanthanum source is lanthanum chloride and its hydrate or lanthanum nitrate and its hydrate, the purity of the lanthanum source is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with Ce element, the cerium source is cerium chloride and its hydrate or cerium nitrate and its hydrate, the purity of the cerium source is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with Pr element, the praseodymium source is praseodymium chloride and its hydrate or praseodymium nitrate and its hydrate Its hydrate, the purity of praseodymium source is 80.0-99.99%, the mass is 5-100 mg; when doped with Nd element, the neodymium source is neodymium chloride and its hydrate or neodymium nitrate and its hydrate, the purity of neodymium source is 80.0-99.99%, the mass is 5-100 mg; when doped with Sm element, the samarium source is samarium chloride and its hydrate or samarium nitrate and its hydrate, the purity of samarium source is 80.0-99.99%, the mass is 5-100 mg; when doped with Eu element, the europium source is europium chloride and its hydrate or europium nitrate and its hydrate, the purity of europium source is 80.0-99.99%, the mass is 5-100 mg; when doped with Gd element, the gadolinium source is europium chloride and its hydrate hydrate or gadolinium nitrate and its hydrate, the purity of the gadolinium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Tb element, the terbium source is terbium chloride and its hydrate or terbium nitrate and its hydrate, the purity of the terbium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Dy element, the dysprosium source is dysprosium chloride and its hydrate or dysprosium nitrate and its hydrate, the purity of the dysprosium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Ho element, the holmium source is holmium chloride and its hydrate or holmium nitrate and its hydrate, the purity of the holmium source is 80.0-99.99%, and the mass is 5-100 mg; when doped with Er element, The erbium source is erbium chloride and its hydrate or erbium nitrate and its hydrate, the purity of the erbium source is 80.0-99.99%, and the mass is 5-100 mg; when doping with Tm element, the thulium source is thulium chloride and its hydrate, thulium nitrate and its hydrate, the purity of the thulium source is 80.0-99.99%, and the mass is 5-100 mg; when doping with Yb element, the ytterbium source is ytterbium chloride and its hydrate or ytterbium nitrate and its hydrate, the purity of the ytterbium source is 80.0-99.99%, and the mass is 5-100 mg; when doping with Lu element, the lutetium source is lutetium chloride and its hydrate or lutetium nitrate and its hydrate, the purity of the lutetium source is 80.0-99.99%, and the mass is 5-100 mg. .

[0016] Furthermore, in step (3), the carbon template is carbon black, graphene, carbon nanotubes, carbon nanospheres, porous carbon or biochar; the ultrasonic time is 0.5 to 3 hours, and the stirring time is 5 to 50 hours.

[0017] Furthermore, in step (4), the stirring temperature is 60 to 150° C., the stirring speed is 100 to 5000 r / min, and the stirring time is 5 to 50 h.

[0018] Furthermore, in step (5), the calcination temperature in the muffle furnace is 300-600° C., the calcination time is 1 h-5 h, and the calcination atmosphere is selected from air atmosphere or oxygen atmosphere.

[0019] Application of transition metal or rare earth element doped ruthenium dioxide catalyst, transition metal or rare earth element doped ruthenium dioxide nanocatalyst as electrochemical oxygen evolution reaction (OER) catalyst, applied to acidic water electrolysis.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The transition metal or rare earth element doped ruthenium dioxide nanocatalyst provided by the present invention has a structure with fine particles and uniform size. The fine particle structure can maximize the active sites exposed on the surface and increase the contact area with the electrolyte, thereby improving the catalytic performance. In addition, doping with transition metals or rare earth elements can optimize the adsorption energy of active sites to oxygen-containing intermediates by adjusting the local electronic structure of the catalyst surface, reduce the energy barrier of the rate-limiting step, and thus improve the reaction activity. At the same time, doping with transition metals or rare earth elements can weaken the overlap between Ru 4d and O 2p orbitals, reduce the covalency of Ru-O bonds, and thus improve the stability of the catalyst. (2) The preparation method proposed by the present invention requires simple equipment, is easy to operate, has controllable conditions, and has high repeatability. The preparation cost is much lower than that of commercial iridium dioxide catalysts; (3) The transition metal or rare earth element doped ruthenium dioxide nanocatalyst exhibits excellent oxygen evolution activity and stability in acidic solutions, and has broad application prospects in the field of PEM water electrolysis and hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1a and Figure 1b This is a scanning electron microscope image of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention;

[0022] Figure 2 This is a low-power transmission electron microscope image of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention;

[0023] Figure 3 This is a high-magnification transmission electron microscope image of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention;

[0024] Figure 4 The XRD spectrum of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention;

[0025] Figure 5a-5fThey are respectively the high-resolution Ru 3p XPS spectrum, the full spectrum, the high-resolution Nb 3d XPS spectrum, the high-resolution Ta 4f XPS spectrum, the high-resolution W 4f XPS spectrum and the high-resolution Mo3d XPS spectrum of the Mo, W, Ta and Nb doped ruthenium dioxide catalyst prepared in the present invention;

[0026] Figure 6a and Figure 6b The molybdenum-doped ruthenium dioxide catalyst prepared by the present invention is heated to 0.5 MH 2 LSV curve and EIS diagram of OER in SO4) electrolyte;

[0027] Figure 7 The molybdenum-doped ruthenium dioxide catalyst prepared by the present invention is heated to 0.5 MH 2 OER stability test curve in SO4) electrolyte. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with specific embodiments and corresponding drawings. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0029] Example 1

[0030] (1) Weighing 100 mg of ruthenium trichloride with a purity of 99.99%, taking 25 mL of a 1 M hydrochloric acid aqueous solution to dissolve the ruthenium trichloride, and further mechanically stirring at a speed of 500 r / min at room temperature for 30 min to obtain a mixed solution A;

[0031] (2) adding 8.9 mg of ammonium molybdate to the mixed solution A, and mechanically stirring the mixture at a speed of 500 r / min at room temperature for 30 min to obtain a mixed solution B;

[0032] (3) adding 200 mg of carbon black for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the carbon black for 1 h, and then mechanically stirring at a speed of 500 r / min at room temperature for 20 h to obtain a mixed suspension C;

[0033] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 85 degrees Celsius and a rotation speed of 500 r / min to remove water from the suspension and fully grind the evaporated sample;

[0034] (5) The ground sample was placed in a porcelain boat, and the porcelain boat was placed in a muffle furnace at 450° C. for air calcination for 3 h. The calcination was used to decompose the carbon black and oxidize the metal ions to obtain molybdenum-doped ruthenium dioxide nanoparticles.

[0035] Figure 1a and Figure 1b The molybdenum-doped ruthenium dioxide (Mo-RuO 2 ), with magnifications of (a) 150,000 times and (b) 60,000 times. 2 They are nanoparticles of uniform size.

[0036] Figure 2 The molybdenum-doped ruthenium dioxide (Mo-RuO 2 ), from which we can see that Mo-RuO2 is a nanoparticle with fine particles and uniform size.

[0037] Figure 3 The molybdenum-doped ruthenium dioxide (Mo-RuO 2 ) from the transmission electron microscope high magnification image; From the transmission electron microscope high magnification image, we can see that Mo-RuO 2 The lattice fringes are obvious and the crystallinity is good, which is the basis of excellent catalytic stability. Molybdenum atoms are doped into the interior of ruthenium dioxide crystals by replacing the position of ruthenium;

[0038] Figure 4 The XRD spectrum of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention shows that all diffraction peaks are similar to those of RuO 2 (PDF#43-1027) has a similar structure to RuO 2 The same crystal structure and no diffraction peak of molybdenum oxide are attributed to the fact that Mo replaces Ru atoms in the form of atoms and is doped into RuO. 2 No impurity phase is generated inside the crystal.

[0039] Figure 5a The high-resolution Ru 3p XPS spectrum of the molybdenum-doped ruthenium dioxide catalyst prepared in the present invention can be deconvoluted into 465.08 Ru4+ and 462.38 Ru 3+ , revealing the complex valence states of +3 and +4 at the Ru site. 2 Compared to Mo-RuO 2 The binding energy of Ru in Mo-RuO has shifted positively. These changes mean that 2 The electron distribution of the metal atoms changes, thereby changing the local electronic structure of the metal atoms. Figure 5fThe high-resolution Mo 3d XPS spectrum of the molybdenum-doped ruthenium dioxide catalyst prepared by the present invention; Mo-RuO 2 The high-resolution Mo 3d XPS spectra show that Mo 5+ The two fitting peaks of Mo (230.87 and 233.97 eV) 6+ There are two fitting peaks (232.34 and 235.48 eV). In addition, Figure 5c-5e The high-resolution Nb 3d XPS spectra, Ta 4f XPS spectra and W4f spectra of the Nb, Ta and W doped ruthenium dioxide catalysts prepared in the present invention are shown in Figure 2. 2 , also showing mixed valence.

[0040] Figure 6a and Figure 6b The molybdenum-doped ruthenium dioxide prepared in the present invention is dissolved in an acidic aqueous solution (0.5 MH 2 LSV curve and EIS diagram of SO4)OER at 10 mA cm -2 Under current density, Mo-RuO 2 The overpotential is only 170mV, which is better than commercial RuO 2 .

[0041] Figure 7 The molybdenum-doped ruthenium dioxide catalyst acid electrolyte (0.5MH 2 SO4)OER stability test curve, Mo-RuO 2 At 100mAcm -2 The OER catalytic reaction continued for 300 hours at the current density, and the stability was still more than 90%. It is better than commercial RuO2, which shows that Mo-RuO 2 Good OER stability in acidic electrolyte.

[0042] Example 2

[0043] (1) Weighing 500 mg of ruthenium trichloride with a purity of 85%, taking 100 mL of 4 M hydrochloric acid aqueous solution to dissolve the ruthenium trichloride, and further mechanically stirring at a speed of 1000 r / min at room temperature for 60 min to obtain a mixed solution A;

[0044] (2) adding 60.5 mg of ammonium metatungstate to the mixed solution A, and mechanically stirring the mixture at a speed of 1000 r / min for 60 min at room temperature to obtain a mixed solution B;

[0045] (3) adding 600 mg of graphene for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the graphene for 3 h, and then mechanically stirring at a speed of 500 r / min at room temperature for 40 h to obtain a mixed suspension C;

[0046] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 120 degrees Celsius and a rotation speed of 1000 r / min to remove water from the suspension and fully grind the evaporated sample;

[0047] (5) The ground sample is placed in a porcelain boat, and the porcelain boat is placed in a muffle furnace at 550° C. for air calcination for 3 h. The calcination is used to decompose graphene and oxidize metal ions to obtain tungsten-doped ruthenium dioxide nanoparticles.

[0048] The tungsten-doped ruthenium dioxide nanocatalyst prepared in this embodiment is composed of tungsten replacing the position of ruthenium element, and its particle size is about 5-20nm.

[0049] The polarization curve of the tungsten-doped ruthenium dioxide nanocatalyst prepared in this embodiment in an acidic (0.5M sulfuric acid) electrolyte shows that the oxygen evolution overpotential of the tungsten-doped ruthenium dioxide nanocatalyst is about 190mV, which effectively reduces additional energy consumption and has good stability.

[0050] Example 3

[0051] (1) Weighing 1000 mg of ruthenium trichloride with a purity of 85%, taking 500 mL of a 3M hydrochloric acid aqueous solution to dissolve the ruthenium trichloride, and further mechanically stirring at a speed of 500 r / min at room temperature for 30 min to obtain a mixed solution A;

[0052] (2) adding 73 mg of tantalum chloride to the mixed solution A, and mechanically stirring the mixture at a speed of 700 r / min at room temperature for 150 min to obtain a mixed solution B;

[0053] (3) adding 1000 mg of biochar for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the biochar for 1 h, and then mechanically stirring at 700 r / min at room temperature for 50 h to obtain a mixed suspension C;

[0054] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 150 degrees Celsius and a rotation speed of 700 r / min to remove water from the suspension and fully grind the evaporated sample;

[0055] (5) The ground sample was placed in a porcelain boat, and the porcelain boat was placed in a muffle furnace at 300° C. for air calcination for 50 h. The calcination was used to decompose the biochar and oxidize the metal ions to obtain tantalum-doped ruthenium dioxide nanoparticles.

[0056] The polarization curve of the tantalum-doped ruthenium dioxide nanocatalyst prepared in this embodiment in an acidic (0.5M sulfuric acid) electrolyte shows that the oxygen evolution overpotential of the tantalum-doped ruthenium dioxide nanocatalyst is about 190mV, which effectively reduces additional energy consumption and has good stability.

[0057] Example 4

[0058] (1) Weighing 500 mg of ruthenium nitrate with a purity of 90%, taking 200 mL of a 2M nitric acid aqueous solution to dissolve the ruthenium nitrate, and further mechanically stirring at a speed of 800 r / min at room temperature for 1 h to obtain a mixed solution A;

[0059] (2) adding 47 mg of ammonium niobate oxalate hydrate to the mixed solution A, and mechanically stirring the mixture at a speed of 800 r / min at room temperature for 1 h to obtain a mixed solution B;

[0060] (3) adding 1300 mg of carbon black for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the carbon black for 2 h, and then mechanically stirring at a speed of 800 r / min at room temperature for 30 h to obtain a mixed suspension C;

[0061] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 130 degrees Celsius and a rotation speed of 800 r / min to remove water from the suspension and fully grind the evaporated sample;

[0062] (5) The ground sample is placed in a porcelain boat, and the porcelain boat is placed in a muffle furnace at 300° C. for air calcination for 5 h. The calcination is used to decompose carbon black and oxidize metal ions to obtain niobium-doped ruthenium dioxide nanoparticles.

[0063] The polarization curve of the niobium-doped ruthenium dioxide nanocatalyst prepared in this embodiment in an acidic (0.5M sulfuric acid) electrolyte shows that the oxygen evolution overpotential of the niobium-doped ruthenium dioxide nanocatalyst is about 190mV, which effectively reduces additional energy consumption and has good stability.

[0064] Example 5

[0065] (1) Weighing 500 mg of ruthenium chloride with a purity of 98%, dissolving the ruthenium chloride in 100 mL of a 1 M hydrochloric acid aqueous solution, and mechanically stirring the mixture at room temperature at a speed of 1000 r / min for 5 h to obtain a mixed solution A;

[0066] (2) adding 50 mg of cerium chloride to the mixed solution A, and mechanically stirring the mixture at a speed of 1000 r / min at room temperature for 5 h to obtain a mixed solution B;

[0067] (3) adding 1100 mg of carbon black for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the carbon black for 5 h, and then mechanically stirring at a speed of 1000 r / min at room temperature for 30 h to obtain a mixed suspension C;

[0068] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 95 degrees Celsius and a rotation speed of 1000 r / min to remove water from the suspension and fully grind the evaporated sample;

[0069] (5) The ground sample was placed in a porcelain boat, and the porcelain boat was placed in a muffle furnace at 550° C. for air calcination for 10 h. The calcination was used to decompose the carbon black and oxidize the metal ions to obtain niobium-doped ruthenium dioxide nanoparticles.

[0070] Example 6

[0071] (1) Weighing 100 mg of ruthenium chloride with a purity of 95%, taking 20 mL of a 1 M hydrochloric acid aqueous solution to dissolve the ruthenium chloride, and further mechanically stirring at a speed of 500 r / min at room temperature for 1 h to obtain a mixed solution A;

[0072] (2) adding 15 mg of praseodymium chloride to the mixed solution A, and mechanically stirring the mixture at a speed of 500 r / min at room temperature for 1 h to obtain a mixed solution B;

[0073] (3) adding 230 mg of carbon black for adsorbing metal ions in the solution to the mixed solution B, ultrasonically dispersing the carbon black for 2 h, and then mechanically stirring at a speed of 700 r / min at room temperature for 18 h to obtain a mixed suspension C;

[0074] (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring at a heating temperature of 85 degrees Celsius and a rotation speed of 1600 r / min to remove water from the suspension and fully grind the evaporated sample;

[0075] (5) The ground sample is placed in a porcelain boat, and the porcelain boat is placed in a muffle furnace at 450° C. for air calcination for 3 h. The calcination is used to decompose the carbon black and oxidize the metal ions to obtain praseodymium-doped ruthenium dioxide nanoparticles.

[0076] The preparation method of transition metal and rare earth doped ruthenium dioxide nanocatalyst disclosed and proposed by the present invention can be realized by those skilled in the art by referring to the content of this article and appropriately changing the conditions, routes and other links. Although the method and preparation technology of the present invention have been described by preferred embodiments, relevant technical personnel can obviously modify or recombine the methods and technical routes described herein without departing from the content, spirit and scope of the present invention to realize the final preparation technology. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the spirit, scope and content of the present invention.

Claims

1. A transition metal or rare earth element doped ruthenium dioxide catalyst, characterized in that: The transition metal or rare earth element doped ruthenium dioxide catalyst is a nanoparticle with uniform size, and the particle diameter thereof is between 0.5-200nm. The transition metal or rare earth element is doped into the ruthenium dioxide lattice.

2. The method for preparing the transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 1, comprising the following steps: (1) weighing a ruthenium metal salt and dissolving it in an acidic aqueous solution, and mechanically stirring it at room temperature to obtain a mixed solution A; (2) adding a transition metal or rare earth element salt to the mixed solution A, and mechanically stirring the mixture at room temperature to obtain a mixed solution B; (3) adding a carbon template for adsorbing metal ions in the solution to the mixed solution B, uniformly dispersing the mixture through ultrasonication, and then mechanically stirring the mixture at room temperature to obtain a mixed suspension C; (4) placing the mixed suspension C on a heating plate for high-temperature mechanical stirring to remove water from the suspension and fully grind the evaporated sample; (5) Taking an appropriate amount of the ground sample and calcining it in air in a muffle furnace, wherein the calcination is used to decompose the carbon template and oxidize the metal ions to obtain transition metal or rare earth element doped ruthenium dioxide nanoparticles.

3. The method for preparing a transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 2, characterized in that: In step (1), the ruthenium source is ruthenium chloride and its hydrate, ruthenium acetylacetonate and its hydrate or ruthenium nitrate and its hydrate, with a purity of 80.0-99.99% and a mass of 10-1000 mg; the acidic solution is nitric acid, hydrochloric acid, sulfuric acid or hydrofluoric acid, with a molar concentration of 0-4 M, a volume of 10-500 mL, a stirring speed of 500-2000 r / min, and a stirring time of 20-180 min.

4. The method for preparing a transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 2, characterized in that: In step (2), the doped transition metals and rare earth elements are Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ta, W, Re, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; when the Sc element is doped, the scandium source is scandium chloride and its hydrate or scandium nitrate and its hydrate, the scandium source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the Ti element is doped, the titanium source is titanium chloride and its hydrate or titanium nitrate and its hydrate, the titanium source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the V element is doped, the vanadium source is vanadium chloride and its hydrate, vanadium nitrate and its hydrate, ammonium vanadate and its hydrate or sodium vanadate and its hydrate, the vanadium source has a purity of 80.0-99.99% and a mass of 5-100 mg. 99.99%, with a mass of 5 to 100 mg; when doped with Cr element, the chromium source is chromium chloride and its hydrate or chromium nitrate and its hydrate, the chromium source purity is 80.0 to 99.99%, and the mass is 5 to 100 mg; when doped with Mn element, the manganese source is manganese chloride and its hydrate, manganese nitrate and its hydrate, the manganese source purity is 80.0 to 99.99%, and the mass is 5 to 100 mg; when doped with Co element, the cobalt source is cobalt chloride and its hydrate or cobalt nitrate and its hydrate, the cobalt source purity is 80.0 to 99.99%, and the mass is 5 to 100 mg; when doped with Ni element, the nickel source is nickel chloride and its hydrate, nickel nitrate and its hydrate, the nickel source purity is 80.0 to 99.99%, and the mass is 5 to 100 mg; doped with Cu element When the copper source is copper chloride and its hydrate or copper nitrate and its hydrate, the copper source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the Zn element is doped, the zinc source is zinc chloride and its hydrate or zinc nitrate and its hydrate, the zinc source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the Y element is doped, the yttrium source is yttrium chloride and its hydrate or yttrium nitrate and its hydrate, the yttrium source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the Zr element is doped, the zirconium source is zirconium chloride and its hydrate or zirconium nitrate and its hydrate, the zirconium source has a purity of 80.0-99.99% and a mass of 5-100 mg; when the Nb element is doped, the niobium source is sodium niobate and its hydrate, ammonium niobate and its hydrate or niobate When doped with Mo element, the molybdenum source is sodium molybdate and its hydrate, ammonium molybdate and its hydrate or molybdenum chloride and its hydrate, the niobium source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Ta element, the tantalum source is sodium tantalate and its hydrate or ammonium tantalate and its hydrate, the tantalum source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with W element, the tungsten source is sodium tungstate and its hydrate, tungsten tantalate and its hydrate or tungsten chloride and its hydrate, the tungsten source purity is 80.0-99.99%, the mass is 5-100 mg; when doped with Re element, the rhenium source is sodium rhenate and its hydrate, tungsten rhenate and its hydrate When La is doped, the lanthanum source is lanthanum chloride and its hydrate or lanthanum nitrate and its hydrate, the lanthanum source purity is 80.0-99.99%, and the mass is 5-100 mg; when Ce is doped, the cerium source is cerium chloride and its hydrate or cerium nitrate and its hydrate, the cerium source purity is 80.0-99.99%, and the mass is 5-100 mg; when Pr is doped, the praseodymium source is praseodymium chloride and its hydrate or praseodymium nitrate and its hydrate, the praseodymium source purity is 80.0-99.99%, and the mass is 5-100 mg; when Nd is doped, the neodymium source is neodymium chloride and its hydrate or neodymium nitrate and its hydrate, the neodymium source purity is 80.0-99.99%.99%, with a mass of 5 to 100 mg; when doped with Sm element, the samarium source is samarium chloride and its hydrate or samarium nitrate and its hydrate, the samarium source purity is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with Eu element, the europium source is europium chloride and its hydrate or europium nitrate and its hydrate, the europium source purity is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with Gd element, the gadolinium source is europium chloride and its hydrate or gadolinium nitrate and its hydrate, the gadolinium source purity is 80.0 to 99.99%, with a mass of 5 to 100 mg; when doped with Tb element, the terbium source is terbium chloride and its hydrate or terbium nitrate and its hydrate, the terbium source purity is 80.0 to 99.99%, with a mass of 5 to 100 mg ~100mg; when doped with Dy element, the dysprosium source is dysprosium chloride and its hydrate or dysprosium nitrate and its hydrate, the purity of the dysprosium source is 80.0~99.99%, and the mass is 5~100mg; when doped with Ho element, the holmium source is holmium chloride and its hydrate or holmium nitrate and its hydrate, the purity of the holmium source is 80.0~99.99%, and the mass is 5~100mg; when doped with Er element, the erbium source is erbium chloride and its hydrate or erbium nitrate and its hydrate, the purity of the erbium source is 80.0~99.99%, and the mass is 5~100mg; when doped with Tm element, the thulium source is thulium chloride and its hydrate, thulium nitrate and its hydrate, the purity of the thulium source is 80.0~99.99%, and the mass is 5~100mg;. When doping the Yb element, the ytterbium source is ytterbium chloride and its hydrate or ytterbium nitrate and its hydrate, the purity of the ytterbium source is 80.0-99.99%, and the mass is 5-100 mg; when doping the Lu element, the lutetium source is lutetium chloride and its hydrate or lutetium nitrate and its hydrate, the purity of the lutetium source is 80.0-99.99%, and the mass is 5-100 mg.

5. The method for preparing a transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 2, characterized in that: In step (3), the carbon template is carbon black, graphene, carbon nanotubes, carbon nanospheres, porous carbon or biochar; the ultrasonic time is 0.5 to 3 hours, and the stirring time is 5 to 50 hours.

6. The method for preparing a transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 2, characterized in that: In step (4), the stirring temperature is 60 to 150° C., the stirring speed is 100 to 5000 r / min, and the stirring time is 5 to 50 h.

7. The method for preparing a transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 2, characterized in that: In step (5), the calcination temperature in the muffle furnace is 300-600° C., the calcination time is 1 h-5 h, and the calcination atmosphere is selected from air atmosphere or oxygen atmosphere.

8. The use of the transition metal or rare earth element doped ruthenium dioxide catalyst according to claim 7, characterized in that: Transition metal or rare earth element doped ruthenium dioxide nanocatalysts are used as electrochemical oxygen evolution reaction (OER) catalysts in acidic water electrolysis.

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