Nano-fiber structured perovskite out-of-solution metal nanoparticle composite materials, methods of making, and use for electrocatalytic methane conversion
By using a perovskite-exsolution metal nanoparticle composite catalyst with a nanofiber structure, the problem of low methane conversion efficiency was solved, achieving efficient conversion to C2 products at low temperatures, thus reducing energy consumption and environmental risks.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN UNIV
- Filing Date
- 2025-01-20
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies are insufficient to efficiently activate methane and convert it into more valuable C2 products. Traditional methods suffer from problems such as high energy consumption, demanding equipment requirements, numerous byproducts, and significant environmental pollution risks.
A nanofiber-structured perovskite-eluent metal nanoparticle composite material was used as a catalyst. The nanofiber structure was prepared by electrospinning to form a metal particle-nanofiber oxide interface, which was used for the non-oxidative direct dehydrogenation of methane in proton-conductive SOEC to promote the conversion of methane into C2 products.
It improves methane conversion and C2 product selectivity, reduces excessive oxidation, increases catalytic active sites, and achieves efficient C2 product production at low temperatures.
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Figure CN119913557B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electrocatalytic methane conversion, more particularly to a nano-fiber structured perovskite out-of-solution metal nanoparticle composite material, a preparation method thereof and use thereof for electrocatalytic methane conversion. BACKGROUND
[0002] In today's chemical industry, C2 products (such as ethane, ethylene, acetylene, etc.) as basic chemical raw materials, their importance is self-evident. They are widely used in the production of plastics, synthetic fibers, rubbers and numerous fine chemicals, and are an indispensable part of modern industry. At present, the traditional C2 production mode mainly relies on petroleum and natural gas as raw materials, and is obtained through cracking process. Petroleum and natural gas are widely available resources worldwide, providing sufficient raw material supply for the C2 industry chain. After long-term development, this production technology has been quite mature, and can realize efficient and stable production, and the C2 industry chain can produce a variety of downstream products to meet the needs of different fields, and has a wide application prospect .
[0003] Due to the strong C-H bond of methane (CH4), the negligible electron affinity, the large ionization energy and the low polarizability, it has a high stability and is difficult to be activated without sufficient energy input . The goal of activating methane and converting it into more valuable chemicals has long been considered an important challenge. Although the methane oxidation coupling (OCM) production mode has the potential to directly generate C2 through the way of incomplete oxidation of methane, and is expected to have better economic benefits, it still has some significant disadvantages in practical application. Due to the dependence of this production mode on high-temperature environment, the energy consumption in the reaction process is increased, and the high-temperature resistance of the equipment is also very high. High temperature is very conducive to the formation of carbon, and the accumulation of carbon on the surface of the catalyst will cause problems such as deactivation and loss of C2 selectivity. In addition, due to the presence of oxygen, CH4 is easy to be over-oxidized to generate CO, CO2 and other by-products, which not only reduces the purity and yield of the product, but also increases the production cost and environmental pollution risk .
[0004] Therefore, we propose an innovative method to avoid the limitations of current C2 production by changing the petroleum chemical production mode from the widely used thermal catalysis to electrocatalysis. We use SOEC for the electrochemical non-oxidative dehydrogenation (NDP) of alkanes to co-produce C2 and hydrogen. SOEC is composed of a dense proton-conducting electrolyte film, a porous cathode support and a modified porous anode. Alkanes are fed to the anode to generate C2 products and H + when a voltage is applied. The generated H +The hydrogen is transferred to the cathode through a dense proton-conducting electrolyte, where it combines with electrons to form high-purity hydrogen. The non-oxidative direct dehydrogenation method avoids the intervention of oxidation reactions and directly obtains the target product through a dehydrogenation process, providing a new idea for solving the above problems. Proton-conducting solid oxide electrolysis cells (H-SOEC) are highly regarded due to their high efficiency, low cost of converting electrical power into fuels and chemicals using renewable electricity, and their unique proton-conduction mechanism However, its lower operating temperature (400-700 o C) is not conducive to the activation of methane. In addition, the reduction of the working temperature also puts higher requirements on the electronic conductivity of the anode material.
[0005] Therefore, to solve the above problems, it is urgent for those skilled in the art to develop a high-performance and high-stability methane dehydrogenation catalyst and promote the practical application of SOEC technology in C2 product production.
[0006] Reference: SUMMARY
[0007] The present application aims to solve the technical problems in the preparation and application of methane conversion catalysts, and provides a nano-fiber structure perovskite out-dissolved metal nanoparticle catalyst and a preparation method thereof, which is applied to the electrocatalytic non-oxidative direct dehydrogenation of methane to produce C2 products. By forming a firm metal particle-nano-fiber oxide interface, suppressing carbon deposition and particle agglomeration, increasing the specific surface area and catalytic active sites, and improving the methane conversion rate and C2 product selectivity.
[0008] The specific technical solutions of the present application are as follows:
[0009] The nano-fiber structure perovskite out-dissolved metal nanoparticle composite material has a molecular formula of Sr2X m Y n Mo q O6-BaZr 0.1 Ce 0.7 Y 0.2 O3, wherein X=Fe, Mg; when X=Fe, m=1.5 and q=0.5; when X=Mg, m=1 and q=1; Y=Fe, Co, Ni; 0.1≥n≥0.001.
[0010] The preparation method of the nano-fiber structure perovskite out-dissolved metal nanoparticle composite material of the present application comprises the following steps:
[0011] (1) Preparation of precursor solution: according to the stoichiometric ratio, the salt solution is dissolved in the solvent, and the polymer is added to prepare the precursor solution;
[0012] (2) through electrostatic spinning method using 10-20 kV voltage charged precursor solution in the electric field stretching thin, and then solvent evaporation to form a thin film of spinning precursor;
[0013] (3) the precursor film obtained by heating 800-1200 o C calcination to remove organic components, obtain nano-fiber structure perovskite materials;
[0014] (4) by 700-900 o C temperature reduction of the solution metal nanoparticles form metal particles-nanofiber oxide interface, obtain nano-fiber structure perovskite solution metal nanoparticles composite materials.
[0015] The salt solution in step (1) is a soluble salt such as nitrate, sulfate, carbonate, hydrochloride.
[0016] The solvent in step (1) is methanol, ethyl acetate, chloroform or N, N-dimethylformamide (DMF).
[0017] The polymer in step (1) is polyethylene terephthalate (PET), polyacrylic acid (PAA) or polyvinylpyrrolidone (PVP).
[0018] The mass fraction of metal salt in the precursor solution in step (1) is 10%-30%, and the mass fraction of polymer is 5%-10%.
[0019] In step (2), the 10-20 kV voltage is a direct current voltage applied between the injector nozzle and the rotating cylinder receiver, and the injector pushing speed is 0.05-0.20 mL h -1 .
[0020] The heating rate in step (3) is 1-5 o C min -1 .
[0021] The nano-fiber structure perovskite solution metal nanoparticle composite material of the application is used for electrocatalytic methane conversion.
[0022] The method for electrocatalytic methane conversion specifically comprises the following steps:
[0023] (1) prepare an electrolyte-supported proton-conducting solid oxide half-cell sheet, then brush the prepared composite material on the half-cell sheet by screen printing, and then obtain an electrolyte-supported proton-conducting solid oxide cell sheet with nano-fiber structure perovskite as anode by calcination.
[0024] (2) The prepared battery piece is brushed with silver paste and sealed in a sealed reactor by sealing glue. The sealed reactor is loaded into a furnace filled with argon atmosphere, and H2 is used to reduce at 700-900 o C.
[0025] (3) After inert gas purging, the anode side is switched to reaction gas-methane and nitrogen mixed gas, and the other side is connected to oxygen (O2). Apply 0-2 V voltage at 550-850 o C.
[0026] The catalyst for preparing C2 products by electrocatalytic methane conversion is as follows:
[0027] A catalyst for preparing C2 products by electrocatalytic methane conversion is provided-Sr2X m Y n Mo q O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 (X=Fe, Mg; when X=Fe, m=1.5, q=0.5; when X=Mg, m=1, q=1; Y=Fe, Co, Ni; 0.1≥n≥0.001) is abbreviated as SXY n M-BZCY.
[0028] The preparation method is as follows:
[0029] (1) Prepare the precursor solution: according to the stoichiometric ratio, dissolve the salt solution in the solvent, add the polymer, and prepare the precursor solution;
[0030] (2) Use 10-20 kV voltage to stretch and refine the charged precursor solution in the electric field by electrospinning method, and then form a composite anode spinning precursor film by solvent evaporation;
[0031] (3) The obtained precursor film is calcined at 800-1200 o C to remove organic components and obtain perovskite anode material with nanofiber structure;
[0032] (4) Reduce at 700-900 o C to form metal particle-nanofiber oxide interface, which is the key to obtaining high catalytic activity and stability of methane conversion reaction.
[0033] Preferably, in step (1), the corresponding salt solution is a soluble salt such as nitrate, sulfate, carbonate, and hydrochloride.
[0034] Preferably, in step (1), the solvent is methanol, ethyl acetate, chloroform, N,N-dimethylformamide (DMF), etc.
[0035] Preferably, in step (1), the polymer is polyethylene terephthalate (PET), polyacrylic acid (PAA), polyvinylpyrrolidone (PVP) and other high molecular polymers with good solubility and stretchability.
[0036] Preferably, in step (1), the mass fraction of the metal salt in the total precursor solution is 10%-30%, and the mass fraction of the polymer is 5%-10%.
[0037] The beneficial effects of the above technical solution are that the raw materials are uniformly dissolved, and the viscosity is moderate.
[0038] Preferably, in step (2), the high voltage is a direct current voltage of 10-20 kV applied between the injector nozzle and the rotating drum receiver, and the control injector pushing speed is 0.05-0.20 mL h -1 .
[0039] The beneficial effects of the above technical solution are that the nozzle stably sprays uniform fibers.
[0040] Preferably, in step (3), the heating rate is 1-5 o C min -1 .
[0041] The beneficial effects of the above technical solution are that the target product is obtained without destroying the fiber structure of the material, and the phase is stable and the micro-morphology is good.
[0042] Preferably, in step (4), the reduction temperature is 700-900 o C.
[0043] The beneficial effects of the above technical solution are that the out-solution particles are obtained without destroying the battery structure, and the particles are well dispersed, uniform in size and not agglomerated.
[0044] A method for catalyzing the conversion of methane into C2 products is provided, including the following operations:
[0045] (1) Prepare an electrolyte-supported proton-conducting solid oxide half-cell sheet, brush the above prepared composite material on the sheet cell by screen printing, and obtain an electrolyte-supported proton-conducting solid oxide cell sheet with a nanofiber structure perovskite as an anode by calcination;
[0046] (2) Brush silver paste on the prepared cell sheet and load it into a sealed reactor for sealing with sealing glue, load the sealed reactor into an argon atmosphere furnace, and reduce it at 700-900 o C using H2.
[0047] (3) After inert gas purging, the anode side is switched to reaction gas-methane and nitrogen mixed gas, and the other side is introduced with oxygen to apply 0-2 V voltage at 550-850 o C.
[0048] Preferably, in step (2), the reduction temperature is 700-900 o C.
[0049] The beneficial effects of this scheme are: without damaging the battery structure, while obtaining well-dispersed, uniform-sized and non-agglomerated out-solution particles.
[0050] Further, the principle of using the nano-fiber structured perovskite out-solution metal nanoparticle as a catalyst for electrocatalytic methane conversion is:
[0051] Methane is cracked to generate H + and active species methyl radicals at the anode side under catalytic action. The proton-conducting SOEC promotes the forward progress of methane conversion by timely pumping H + in the product to the cathode side. Methyl radicals continue to generate C2 and other products through chain reactions. H + pumped to the cathode reacts with O2 to generate H2O. At the same time, due to not directly reacting with O 2- , excessive oxidation in the methane conversion process is reduced.
[0052] The beneficial effects obtained by the present application are:
[0053] (1) The present application prepares SXY n M-BZCY anode material with disordered stacked three-dimensional network fiber structure by electrospinning method. SXY n M phase and BZCY phase are uniformly distributed in the composite anode, which expands the three-phase reaction interface and promotes the close combination of the anode and the electrolyte. The disordered stacked three-dimensional network fiber structure of the anode material greatly improves the porosity, increases the specific surface area and active site number of the anode, and further affects the methane dehydrogenation catalytic performance.
[0054] (2) The present application forms a firm metal particle-nano-fiber oxide interface by in-situ reduction out-solution, and uses it for the performance research of methane non-oxidation direct dehydrogenation of proton-conducting SOEC. The particle agglomeration and carbon deposition are inhibited, and the catalytic active site is increased, thereby improving the methane conversion rate and the selectivity of C2 products.
[0055] (3) The proton-conducting SOEC promotes the forward progress of methane conversion by timely pumping H + in the product to the cathode side, and reduces excessive oxidation in the methane conversion process due to not directly reacting with O 2- . BRIEF DESCRIPTION OF DRAWINGS
[0056] Figure 1 Cross-sectional SEM image of electrolyte-supported single cell prepared in Example 8;
[0057] Figure 2 Schematic diagram of application process;
[0058] Figure 3 Cross-sectional image of cell after anode application of Sr2Fe 1.5 Fe 0.001 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 as anode application;
[0059] Figure 4 Cross-sectional image of cell after anode application of Sr2Fe 1.5 Fe 0.075 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 as anode application. DETAILED DESCRIPTION
[0060] In order to further illustrate the present application, the method for electrocatalytic efficient conversion of CH4 to C2 using nanofiber structured perovskite out-diffusion metal nanoparticle catalyst provided by the present application is described below in conjunction with examples. The following examples are only to enable a person skilled in the art to have a more comprehensive understanding of the present application, and all other examples obtained by a person skilled in the art without creative labor are within the scope of protection of the present application.
[0061] Example 1
[0062] 30 mL, i.e. 28.32 g of N,N-dimethylformamide (DMF) was measured in a beaker, 0.885 g of Sr(NO3)2, 1.262 g of Fe(NO3)3·9H2O, 0.185 g of (NH4)6Mo7O 24 ·4H2O, 0.383 g of Ba(NO3)2, 0.063 g of Zr(NO3)4, 0.443 g of Ce(NO3)3·6H2O, and 0.112 g of Y(NO3)3·6H2O were weighed, and after dissolution, 1.67 g of polyvinylpyrrolidone (PVP) in DMF was added. At this time, the mass fraction of metal salt was 10%, and the mass fraction of PVP was 5%. The PVP was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0063] The precursor solution was transferred into a 10 mL plastic syringe, and the distance between the needle and the drum receiver was adjusted to 18 cm to make the liquid form nanoscale fibers through flight and stretching. A direct current voltage of 10 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.05 mL h -1 to make the nozzle spray fibers. A stable spinning of about 24 h can obtain a spinning precursor film.
[0064] The obtained precursor film was naturally dried at room temperature for 5 h, and then placed in a muffle furnace at 1 o C min -1 to 800 o C for 5 h to remove the organic components to obtain Sr2Fe 1.5 Fe 0.001 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite material.
[0065] Example 2
[0066] 28.32 g of methanol was measured in a beaker, and 0.893 g of Sr(NO3)2, 1.294 g of Fe(NO3)3·9H2O, 0.187 g of (NH4)6Mo7O 24 ·4H2O, 0.389 g of Ba(NO3)2, 0.064 g of Zr(NO3)4, 0.451 g of Ce(NO3)3·6H2O, and 0.114 g of Y(NO3)3·6H2O were weighed and dissolved, and then 2.2 g of polyethylene terephthalate (PET) in methanol was added. At this time, the mass fraction of metal salt is 10%, and the mass fraction of PET is 6.5%. The PET was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0067] The precursor solution was transferred into a 10 mL plastic syringe, and the distance between the needle and the drum receiver was adjusted to 18 cm to make the liquid form nanoscale fibers through flight and stretching. A direct current voltage of 10 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.05 mL h -1 to make the nozzle spray fibers. A stable spinning of about 24 h can obtain a spinning precursor film.
[0068] The obtained precursor film was naturally dried at room temperature for 5 h, and then placed in a muffle furnace at 1 o C min -1 to 900 oC for 5 h, and the organic components were removed to obtain Sr2Fe 1.5 Fe 0.025 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite.
[0069] Example 3
[0070] 28.32 g of ethyl acetate was measured in a beaker, 0.894 g of Sr(NO3)2, 1.316 g of Fe(NO3)3·9H2O, 0.187 g of (NH4)6Mo7O 24 ·4H2O, 0.393 g of Ba(NO3)2, 0.064 g of Zr(NO3)4, 0.455 g of Ce(NO3)3·6H2O, and 0.115 g of Y(NO3)3·6H2O were weighed and dissolved in ethyl acetate with polyacrylic acid (PAA). At this time, the mass fraction of metal salt was 10%, and the mass fraction of PAA was 7.3%. After stirring at room temperature for 12 h to completely dissolve the PAA, a metal precursor solution was obtained.
[0071] The precursor solution was transferred into a 10 mL plastic syringe, and the distance between the needle and the drum receiver was adjusted to 18 cm to form nanoscale fibers by liquid flight and stretching. A direct current voltage of 14 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.10 mL h -1 to make the nozzle spray fibers stably. A spinning precursor film was obtained by continuously and stably spinning for about 24 h.
[0072] The obtained precursor film was naturally dried at room temperature for 5 h, and then placed in a muffle furnace at 3 o C min -1 The temperature was increased to 1000 o C for 5 h, and the organic components were removed to obtain Sr2Fe 1.5 Fe 0.050 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite.
[0073] Example 4
[0074] 28.32 g of chloroform was measured in a beaker, 1.467 g of Sr(NO3)2, 2.194 g of Fe(NO3)3·9H2O, 0.307 g of (NH4)6Mo7O 24• 4H2O, 0.651 g Ba(N03)2, 0.106 g Zr(N03)4, 0.753 g Ce(N03)3-6H2O, 0.190 g Y(N03)3-6H2O were dissolved and 3.77 g polyvinylpyrrolidone (PVP) in chloroform was added. At this time, the mass fraction of metal salts was 15% and the mass fraction of PVP was 10%. The PVP was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0075] The precursor solution was transferred into a 10 mL plastic syringe, the distance between the needle and the drum receiver was adjusted to 18 cm, and the liquid was formed into nanoscale fibers by flight and stretching. A direct current voltage of 15 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.12 mL h -1 to make the nozzle spray fibers stably. A spinning precursor film was obtained by continuously and stably spinning for about 24 h.
[0076] The obtained precursor film was naturally dried at room temperature for 5 h, and then placed in a muffle furnace to be heated at a rate of 4 o C min -1 to 1100 o C and kept for 5 h to remove the organic components to obtain Sr2Fe 1.5 Fe 0.075 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite material.
[0077] Example 5
[0078] 28.32 g of N,N-dimethylformamide (DMF) was measured in a beaker, and 2.008 g of Sr(N03)2, 3.052 g of Fe(N03)3-9H2O, 0.421 g of (NH4)6Mo7O 24 ·4H2O, 0.899 g Ba(N03)2, 0.147 g Zr(N03)4, 1.041 g Ce(N03)3-6H2O, 0.262 g Y(N03)3-6H2O were dissolved and 3.0 g of polyvinylpyrrolidone (PVP) in DMF was added. At this time, the mass fraction of metal salts was 20% and the mass fraction of PVP was 7.66%. The PVP was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0079] The precursor solution was transferred into a 10 mL plastic syringe, and the distance between the needle and the drum receiver was adjusted to 18 cm to make the liquid form nanoscale fibers through flight and stretching. A direct current voltage of 16 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.14 mL h -1 to make the nozzle stably spray fibers. A spun precursor film can be obtained by continuously stably spinning for about 24 h.
[0080] The obtained precursor film was naturally dried at room temperature for 5 h and then placed in a muffle furnace to be heated at 1 o C min -1 to 1200 o C for 5 h to remove the organic components to obtain Sr2Fe 1.5 Fe 0.1 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite material.
[0081] Example 6
[0082] 28.32 g of N,N-dimethylformamide (DMF) was measured in a beaker, and 2.614 g of Sr(NO3)2, 1.592 g of Mg(NO3)2·6H2O, 0.179 g of Ni(NO3)2·6H2O, 1.096 g of (NH4)6Mo7O 24 ·4H2O, 0.899 g of Ba(NO3)2, 0.147 g of Zr(NO3)4, 1.041 g of Ce(NO3)3·6H2O, and 0.262 g of Y(NO3)3·6H2O were weighed according to the stoichiometric ratio, and 3.0 g of PVP in DMF was added after dissolution. At this time, the mass fraction of metal salts was 20%, and the mass fraction of PVP was 7.66%. The PVP was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0083] The precursor solution was transferred into a plastic syringe, and the distance between the needle and the drum receiver was adjusted to 18 cm to make the liquid form nanoscale fibers through flight and stretching. A direct current voltage of 16 kV was applied between the syringe nozzle and the drum receiver, and the syringe pushing speed was controlled at 0.18 mL h -1 to make the nozzle stably spray fibers. A spun precursor film can be obtained by continuously stably spinning for about 24 h.
[0084] The obtained precursor film was naturally dried at room temperature for 5 h and then placed in a muffle furnace to be heated at 1 o C min -1 to 900o C for 5 h, and the organic components were removed to obtain Sr2MgNi 0.1 MoO6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite material.
[0085] Example 7
[0086] 28.32 g of N,N-dimethylformamide (DMF) was measured in a beaker, and 2.614 g of Sr(NO3)2, 1.592 g of Mg(NO3)2·6H2O, 0.179 g of Co(NO3)2·6H2O, 1.096 g of (NH4)6Mo7O 24 ·4H2O, 0.899 g of Ba(NO3)2, 0.147 g of Zr(NO3)4, 1.041 g of Ce(NO3)3·6H2O, and 0.262 g of Y(NO3)3·6H2O were weighed according to the stoichiometric ratio, and 3.0 g of PVP in DMF was added after dissolution. At this time, the mass fraction of metal salt was 20%, and the mass fraction of PVP was 7.66%. The PVP was completely dissolved by stirring at room temperature for 12 h to obtain a metal precursor solution.
[0087] The precursor solution was transferred into a plastic syringe, and the distance between the needle and the rotating cylinder receiver was adjusted to 18 cm to form nanoscale fibers by liquid flight and stretching. A direct current voltage of 20 kV was applied between the syringe nozzle and the rotating cylinder receiver, and the syringe pushing speed was controlled at 0.20 mL h -1 to make the nozzle spray fibers stably. A spinning precursor film can be obtained by continuously and stably spinning for about 24 h.
[0088] The obtained precursor film was naturally dried at room temperature for 5 h, and then placed in a muffle furnace to be heated at a rate of 5 o C min -1 to 1200 o C for 5 h, and the organic components were removed to obtain Sr2MgNi 0.1 MoO6-BaZr 0.1 Ce 0.7 Y 0.2 O3 nanofiber composite material.
[0089] Example 8
[0090] The composite material Sr2Fe 1.5 Fe 0.001 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2O3 was screen-printed onto the electrolyte side of an electrolyte-supported proton-conducting solid oxide half-cell using a 100-mesh screen. After drying in an oven, it was then heated at 950°C. o Calcination under air at C for 3 hours forms as shown Figure 1 The single cell shown has an anode thickness of approximately 40 μm and an electrolyte thickness of approximately 508 μm.
[0091] Silver paste is applied to the surface of the solar cells as a current collector layer at 400. o The battery structure obtained by calcination in air at C for 1 h is as follows: Figure 2 As shown, the reactor is loaded into a sealed reactor and sealed with sealant. The sealed reactor is then placed into a reactor filled with an argon atmosphere, and then subjected to a 5-degree Celsius induction process. o C min -1 Heat up to 260 o Incubate at C for 1 hour. Infuse the anode side with a flow rate of 40 ml / min. -1 The H2 continued to heat up to 800 o Reduction at C for 1 hour. After reduction, cool to 700°C. o C. First, purge the hydrogen with nitrogen for half an hour, then switch to a 10% CH4-90% N2 reaction gas with a total flow rate of 20 ml / min, and purge the cathode side with 20 ml / min. -1 O2, at 700 o IV and IT curves were obtained using a VersaSTAT3 electrochemical workstation at temperature C. Product analysis was performed using an online gas chromatograph (GC9790Plus, Fuli). Detailed data are shown in Table 1.
[0092] Table 1 700 o C under Sr2Fe 1.5 Fe 0.001 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 anode electrocatalytic methane conversion reaction performance
[0093] Voltage Conversion rate [C2H6 selectivity] [C2H4 selectivity] [C2 total selectivity] [C2 yield] OCV 0.96% 22.90% 3.71% 26.61% 0.25% 0.5 V 1.70% 23.90% 4.74% 28.64% 0.49% 1.0 V 2.47% 25.70% 5.13% 30.83% 0.76% 1.5 V 3.20% 27.00% 5.33% 32.33% 1.03% 2.0 V 3.68% 29.61% 5.71% 35.32% 1.30%
[0094] Cross-sectional view of the battery cell after application is shown below Figure 3 As shown, when n=0.001, there are fewer metal particles leached from the anode; after the test, the fiber structure of the anode material in the cell remains intact, indicating the presence of Sr2Fe. 1.5 Fe 0.001 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2The single-cell stability of the O3 anode is relatively good. With increasing voltage, the methane conversion rate increases, and the C2 yield and selectivity also increase.
[0095] Example 9
[0096] The Sr2Fe composite material prepared in Example 3 1.5 Fe 0.05 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 Using O3 as the anode, the anode was printed onto the electrolyte side of the electrolyte-supported proton-conducting solid oxide half-cell cell through a 100-mesh screen. After drying in an oven, it was then heated at 950°C. o Single-cell cells are formed by calcination in air at C for 3 hours.
[0097] Silver paste is applied to the surface of the solar cells as a current collector layer at 400. o Calcination under air at C for 1 h yielded the following: Figure 2 The battery structure shown is installed in a sealed reactor and sealed with sealant. The sealed reactor is then placed in a reactor filled with an argon atmosphere, and then subjected to a 5-degree Celsius reaction. o C min -1 Heat up to 260 o Incubate at C for 1 hour. Infuse the anode side with a flow rate of 40 ml / min. -1 The H2 continued to heat up to 800 o Reduction at C for 1 hour. After reduction, cool to 700°C. o C. First, purge the hydrogen with nitrogen for half an hour, then switch to a 30% CH4-70% N2 reaction gas with a total flow rate of 20 ml / min, and purge the cathode side with 20 ml / min. -1 O2, at 700 o IV and IT curves were obtained using a VersaSTAT3 electrochemical workstation at temperature C. Product analysis was performed using an online gas chromatograph, and detailed data are shown in Table 2.
[0098] Table 2 700 o C under Sr2Fe 1.5 Fe 0.05 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 anode electrocatalytic methane conversion reaction performance
[0099] Voltage Conversion rate [C2H6 selectivity] [C2H4 selectivity] [C2 total selectivity] [C2 yield] OCV 1.84% 25.79% 1.71% 27.50% 0.51% 0.5 V 3.37% 29.10% 2.02% 31.12% 1.05% 1.0 V 3.83% 34.56% 1.12% 35.68% 1.37% 1.5 V 4.71% 37.01% 1.17% 38.18% 1.80% 2.0 V 5.51% 38.58% 0.61% 39.70% 2.19%
[0100] With increasing dissolution volume, the number of active sites increases, leading to improved methane conversion and selectivity. At 2.0 V, the methane conversion and C2 selectivity reached 5.51% and 38.58%, respectively, with a C2 yield of 2.19%.
[0101] Example 10
[0102] The Sr2Fe composite material prepared in Example 4 1.5 Fe 0.075 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 Using O3 as the anode, the anode was printed onto the electrolyte side of the electrolyte-supported proton-conducting solid oxide half-cell cell through a 100-mesh screen. After drying in an oven, it was then heated at 950°C. o Single-cell cells are formed by calcination in air at C for 3 hours.
[0103] Silver paste is applied to the surface of the solar cells as a current collector layer at 400. o Calcination under air at C for 1 h yielded the following: Figure 2 The battery structure shown is installed in a sealed reactor and sealed with sealant. The sealed reactor is then placed in a reactor filled with an argon atmosphere, and then subjected to a 5-degree Celsius reaction. o C min -1 Heat up to 260 o Incubate at C for 1 hour. Infuse the anode side with a flow rate of 40 ml / min. -1 The H2 continued to heat up to 800 o Reduction at C for 1 hour. After reduction, cool to 700°C. o C. First, purge the hydrogen with nitrogen for half an hour, then switch to a 25% CH4-75% N2 reaction gas with a total flow rate of 20 ml / min, and purge the cathode side with 20 ml / min of the reaction gas. -1 O2, at 700 o IV and IT curves were obtained using a VersaSTAT3 electrochemical workstation at temperature C. Product analysis was performed using an online gas chromatograph, and detailed data are shown in Table 3.
[0104] Table 3 700 o C under Sr2Fe 1.5 Fe 0.075 Mo 0.5 O6-BaZr 0.1 Ce 0.7 Y 0.2 O3 anode electrocatalytic methane conversion reaction performance
[0105] Voltage Conversion rate [C2H6 selectivity] [C2H4 selectivity] [C2 total selectivity] [C2 yield] OCV 2.87% 24.25% 3.69% 27.94% 0.80% 0.5 V 4.26% 30.13% 2.62% 32.74% 1.40% 1.0 V 5.55% 32.53% 4.36% 36.88% 2.05% 1.5 V 7.01% 34.29% 5.31% 39.60% 2.78% 2.0 V 8.40% 36.31% 6.18% 41.19% 3.46%
[0106] The cross-section of the battery piece after application is shown in Figure 4 As shown in the cross-section of the battery piece after application, it can be found that the fiber structure of the anode material in the battery piece is well maintained. When n = 0.075, the anode out-dissolved particles are uniform and appropriate in size, and the C2 yield is the highest, being 3.46%. Compared with the traditional C2 production method, the perovskite out-dissolved metal nanoparticle catalyst with a nanofiber structure can inhibit carbon deposition and particle agglomeration, increase the specific surface area and catalytic active sites, and improve the methane conversion rate and C2 product selectivity by forming a firm metal particle-nanofiber oxide interface. The fiber and out-dissolution after application are still well maintained, indicating that the single battery with the perovskite out-dissolved metal nanoparticle composite material with a nanofiber structure as the anode has good stability and methane conversion catalytic activity under 700 o C.
[0107] The present application relates to a perovskite out-dissolved metal nanoparticle composite material with a nanofiber structure, a preparation method and an application in electrocatalytic methane conversion. The preparation method comprises the following steps: preparing a precursor solution; synthesizing a composite spinning precursor film by an electrospinning method; removing organic components by high-temperature calcination to obtain nanofibers; and forming a firm metal particle-nanofiber oxide interface by reducing and out-dissolving metal nanoparticles. The material is applied to the non-oxidative direct conversion of methane in a proton-conducting solid oxide electrolysis cell, and can obtain a high C2 yield and good stability at normal pressure and low reaction temperature.
[0108] The above description of the preferred embodiments of the present application is not limited to the specific implementation described above. Those skilled in the art can make various improvements and modifications to the present application without departing from the principles of the present application and the scope of protection of the claims, and these are all within the scope of protection of the present application.
Claims
1. A nanofiber-structured perovskite-eluent metal nanoparticle composite material; characterized in that, The molecular formula is: Sr2X m Y n Mo q O6-BaZr 0.1 Ce 0.7 Y 0.2 O3, where Y=Fe, Co, Ni; 0.1≥n≥0.001, X=Fe, Mg; when X=Fe, m=1.5, q=0.5; when X=Mg, m=1, q=1; The preparation method includes the following steps: (1) Preparation of precursor solution: Weigh the salt solution according to the stoichiometric ratio, dissolve it in the solvent, add the polymer, and prepare the precursor solution; (2) The precursor solution is stretched and refined in an electric field by using a voltage of 10-20 kV through electrospinning, and then the solvent is evaporated to form a spinning precursor film. (3) The obtained precursor film is heated to 800-1200°C. o C-calcination removes organic components to obtain perovskite materials with nanofiber structures; (4) Through 700-900 o At temperature C, the metal nanoparticles are reduced to form a metal particle-nanofiber oxide interface, thus obtaining a perovskite exsolvable metal nanoparticle composite material with nanofiber structure.
2. The method for preparing the nanofiber structured perovskite exsolution metal nanoparticle composite material according to claim 1, characterized in that, Includes the following steps: (1) Preparation of precursor solution: Weigh the salt solution according to the stoichiometric ratio, dissolve it in the solvent, add the polymer, and prepare the precursor solution; (2) The precursor solution is stretched and refined in an electric field by using a voltage of 10-20 kV through electrospinning, and then the solvent is evaporated to form a spinning precursor film. (3) The obtained precursor film is heated to 800-1200°C. o C-calcination removes organic components to obtain perovskite materials with nanofiber structures; (4) Through 700-900 o At temperature C, the metal nanoparticles are reduced to form a metal particle-nanofiber oxide interface, thus obtaining a perovskite exsolvable metal nanoparticle composite material with nanofiber structure.
3. The preparation method according to claim 2, characterized in that, The solvent in step (1) is methanol, ethyl acetate, chloroform or N,N-dimethylformamide.
4. The preparation method according to claim 2, characterized in that, In step (1), the polymer is polyester, polyethylene terephthalate, polyacrylic acid, or polyvinylpyrrolidone.
5. The preparation method according to claim 2, characterized in that, In step (1), the mass fraction of the metal salt in the precursor solution is 10%-30%, and the mass fraction of the polymer is 5%-10%.
6. The preparation method according to claim 2, characterized in that, In step (2), the 10-20 kV voltage is the DC voltage applied between the syringe nozzle and the rotary receiver, and the syringe feed rate is 0.05-0.20 mL / h. -1 .
7. The preparation method according to claim 2, characterized in that, The heating rate in step (3) is 1-5. o C min -1 .
8. The nanofiber structured perovskite exsolution metal nanoparticle composite material as described in claim 1 is used for electrocatalytic methane conversion.