Reforming catalysts, methods of making and using the same, and methods of dry reforming of ethane and carbon dioxide

Abstract

The present application provides a reforming catalyst, a preparation method and application thereof. The catalyst contains a carrier and a reforming active component supported on the carrier. The reforming active component elements include iron and a transition metal. The reduction peak temperature of the surface active metal in the hydrogen temperature programmed reduction test is less than or equal to the reduction peak temperature of a sample with a corresponding active component dispersion of 50%. And / or the active metal is dispersedly distributed on the surface of the carrier. The method comprises: contacting a solution containing a source of the reforming active component with a source of the carrier in equal volumes, the polarity of the solvent in the solution or the weighted polarity in terms of mole fraction is weak polarity, and then drying and calcining. The present application provides a method for dry reforming of ethane and carbon dioxide. The preparation method of the catalyst of the present application controls the polarity of the mixed solvent in the one-step equal-volume co-impregnation, so as to obtain a surface structure with controllable active component distribution. The preparation method of the catalyst of the present application is simple, has little influence on the environment, and is suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to reforming catalysts, their preparation methods and applications, and methods for dry reforming of ethane and carbon dioxide. Background Technology

[0002] Supported catalysts are catalysts in which the active component and co-catalyst are uniformly dispersed and supported on a selected support. The distribution of the active component on the support surface has a significant impact on catalytic reactivity. There is a strong metal-support interaction between the transition metal active component and the variable valence oxide support. The activity and selectivity of the catalytic reaction can be controlled by changing the strength of the interaction between the active component and the support and the interfacial density.

[0003] Low-carbon alkanes (C2-C4) are an important component of shale gas, accounting for up to 15% of the volume in the richest reserves. The reaction of low-carbon alkanes with carbon dioxide (CO2) mainly involves dry reforming and oxidative dehydrogenation, with the main products being syngas or ethylene, thus possessing high economic and social value. During the reaction, controlling whether the C-C bonds of the low-carbon alkanes are broken leads to different reaction selectivity, i.e., breaking the C-C bonds to generate syngas or only breaking the CH bonds to generate ethylene. Currently, ethane dry reforming catalyst systems include the silicalite-1 zeolite-supported chromium catalyst (CN106563489A) from Fudan University and the porous chromium trioxide catalyst (CN107175100A) from the Beijing Research Institute of Chemical Industry, Sinopec. Chromium-based catalysts are highly toxic and environmentally unfriendly; therefore, the development of non-chromium-based dry reforming catalysts shows great promise for application. Studies have shown that the selectivity of the reaction products of low-carbon alkanes and carbon dioxide is closely related to the reaction phase interface, and the distribution of active components on the support surface can be effectively controlled to control the reaction products (PNAS2018,115,8278). Summary of the Invention

[0004] The purpose of this invention is to provide a reforming catalyst with different physicochemical properties such as the dispersed distribution of metal active components. The preparation method of this catalyst is simple, has little environmental impact, and is very suitable for large-scale production.

[0005] According to a first aspect of the present invention, the present invention provides a reforming catalyst comprising a support and a reforming active component supported on the support, the reforming active component comprising iron and transition metals, wherein the reduction peak temperature of the active metal on the catalyst surface in a hydrogen programmed temperature reduction test is less than or equal to the reduction peak temperature of a sample with a corresponding active component dispersion of 50%; and / or the active metal is dispersed on the surface of the support.

[0006] According to a second aspect of the present invention, the present invention provides a method for preparing the catalyst of the present invention, wherein the method comprises: impregnating and contacting a solution containing a reforming active component source with a support source in an equal volume, wherein the polarity or weighted polarity of the solvent in the solution is weakly polar, followed by drying and calcination.

[0007] According to a third aspect of the invention, the invention provides the application of the catalyst described herein in reforming, preferably in dry reforming.

[0008] According to a fourth aspect of the present invention, the present invention provides a method for dry reforming ethane and carbon dioxide, wherein the method comprises: reducing a catalyst, and then contacting ethane and carbon dioxide with a reduced catalyst, said catalyst being the catalyst described in the present invention.

[0009] The catalyst preparation method of the present invention can adjust the selectivity of the catalyst for dry reforming of low-carbon alkanes by changing the distribution of multi-metal active components on the support surface through control of synthesis conditions.

[0010] The catalyst preparation method of the present invention controls the polarity of the mixed solvent in a one-step equal-volume co-impregnation process to obtain a surface structure with controllable distribution of active components.

[0011] The catalytic selectivity regulation of the catalyst in this invention is the result of metal-support interaction.

[0012] The catalyst preparation method of this invention is simple, has little environmental impact, and is suitable for large-scale production.

[0013] The method of this invention, by controlling the equal-volume impregnation process and the polarity of the impregnation solvent during the impregnation of the active component, can effectively regulate the surface structure of the multi-metal active component supported catalyst, thereby obtaining a high-performance reforming catalyst, particularly suitable for the dry reforming of ethane and carbon dioxide. The catalyst synthesis method used in this invention is versatile and applicable to various supported catalysts with different compositions. Attached Figure Description

[0014] The accompanying drawings provide a further understanding of the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0015] Figure 1 The images shown are scanning transmission microscopy (STEM) images (1a) and energy dispersive X-ray spectroscopy (EDS mapping) images (1b-1f) of the active metals in catalyst A of Example 1 dispersed on the surface of the support. Among them, 1b is a stacked distribution map of each element, 1c is a distribution map of Ce, 1d is a distribution map of Al, 1e is a distribution map of Fe, and 1f is a distribution map of Pt.

[0016] Figure 2 The images show the hydrogen-programmed temperature reduction (H2-TPR) images of the active metals of catalyst A in Example 1 and catalyst G in Comparative Example 1 on the support surface. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] This invention provides a reforming catalyst comprising a support and a reforming active component loaded on the support. The reforming active component includes iron and transition metals. The reduction peak temperature of the active metal on the catalyst surface during a hydrogen-programmed reduction test is less than or equal to the reduction peak temperature of a sample with a corresponding active component dispersion of 50%; and / or the active metal is dispersed on the support surface. The catalyst having the aforementioned structure of this invention has the advantages of high reactivity, good stability, simple synthesis method, and environmental friendliness.

[0019] In this invention, the active metal is dispersed on the surface of the support, which is confirmed by scanning transmission microscopy (STEM) images and energy dispersive X-ray spectroscopy (EDS mapping) images. The final scan transmission microscopy (STEM) images and energy dispersive X-ray spectroscopy (EDS mapping) images show that the active component is dispersed on the surface of the support.

[0020] In this invention, the standard for hydrogen temperature-programmed reduction test is to test the sample under a 10% volume fraction hydrogen / argon mixed atmosphere with a space velocity of 50 mL / min and a heating rate of 10 °C / min.

[0021] In this invention, scanning transmission microscopy (STEM) images and energy-dispersive X-ray spectroscopy (EDSmapping) images are obtained using a spherical aberration-corrected transmission electron microscope (TEM) with an accelerating voltage of 200 kV. An ethanol solution containing the sample to be tested is dropped onto a copper grid covered with an ultrathin carbon film and allowed to air dry naturally, serving as the sample for TEM characterization.

[0022] According to a preferred embodiment of the present invention, the active metal is dispersed on the surface of the support, and the dispersion of the active component is 67-96%. The catalyst having the aforementioned structure of the present invention has the advantages of high catalytic activity and good dry reforming selectivity.

[0023] In this invention, the methods for calculating the dispersion include chemisorption and transmission electron microscopy. These methods are well-known to those skilled in the art and will not be described in detail here.

[0024] In this invention, the ratio of the catalyst support and the active component can be flexibly adjusted, and can be selected according to needs. According to a preferred embodiment of the present invention, the catalyst comprises 90-99.5 parts of support and 0.5-10 parts of reforming active component based on oxides, preferably containing 0.5-4 parts of reforming active component based on oxides, based on the mass fraction of the catalyst.

[0025] According to a preferred embodiment of the present invention, the molar ratio of the transition metal element to the iron element is 1:0.2 to 1:1, preferably 1:0.2 to 1:0.6. Therefore, the catalyst has the advantages of high stability and long lifespan.

[0026] According to a preferred embodiment of the present invention, the reduction peak temperature of the active metal on the catalyst surface in a hydrogen temperature-programmed reduction test is less than or equal to 210°C. This indicates that the active component has good dispersibility on the support surface, thus giving the catalyst the advantages of high activity and high selectivity.

[0027] In this invention, the range of transition metals that can be selected is relatively wide, and commonly used transition metals can all be used in this invention. According to a preferred embodiment of this invention, the transition metal is selected from one or more of ruthenium (Ru), iridium (Ir), rhodium (Rh), rhenium (Re), osmium (Os), iridium (Ir), and platinum (Pt), and is preferably selected from one or more of iridium, rhodium, and platinum.

[0028] In this invention, the range of carrier types is relatively wide, and commonly used carriers can all be used in this invention. According to a preferred embodiment of this invention, the carrier is a variable-valence oxide and / or a composite oxide.

[0029] In this invention, the carrier is preferably selected from one or more oxides or composite oxides formed from titanium, cerium, aluminum, magnesium, zirconium, and silicon.

[0030] Catalysts possessing the aforementioned properties of this invention can all be used in this invention, and there are no special requirements for their preparation methods. According to a preferred embodiment of this invention, this invention provides a method for preparing a catalyst, the method comprising: impregnating and contacting a solution containing a reforming active component source with a support source in equal volume, wherein the polarity or weighted polarity of the solvent (single solvent or mixed solvent) in the solution is weakly polar, and then drying and calcining.

[0031] In this invention, the polarity or weighted polarity in mole fractions refers to the sum of the product of the polarity of the corresponding pure solvent and its mole fraction. This is known to those skilled in the art and will not be described in detail here.

[0032] The catalyst prepared by the aforementioned method can be modified by controlling the synthesis conditions to change the distribution of multi-metallic active components on the support surface, thereby adjusting the selectivity of the catalyst for reforming reactions, especially dry reforming reactions of low-carbon alkanes.

[0033] The catalytic selectivity regulation of the catalyst in this invention is the result of metal-support interaction.

[0034] The catalyst preparation method of this invention is simple, has little environmental impact, and is suitable for large-scale production.

[0035] The method of this invention, by controlling the equal-volume impregnation process and the polarity of the impregnation solvent during the impregnation of the active component, can effectively regulate the surface structure of the multi-metal active component supported catalyst, thereby obtaining a high-performance reforming catalyst, which is particularly suitable for the dry reforming of ethane and carbon dioxide. The catalyst synthesis method used in this invention is versatile and applicable to various supported catalysts with different compositions.

[0036] According to a preferred embodiment of the present invention, the polarity of the solvent in the solution is in the range of 3.9 to 6.0, preferably 3.9 to 5.4. According to the catalyst preparation method of the present invention, by controlling the polarity of the solvent or mixed solvent in a one-step equal-volume co-impregnation step, a surface structure with controllable distribution of active components is obtained.

[0037] Solvents with the aforementioned properties can be used in this invention. According to a preferred embodiment of this invention, the solvent is selected from at least one of water, methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, isobutanol, acetone, formic acid, acetic acid, ethyl acetate, N,N-dimethylformamide, acetonitrile, cyclohexane, and petroleum ether, and preferably selected from one or more of water, ethanol, isobutanol, and acetone.

[0038] According to a preferred embodiment of the present invention, the step of equal-volume impregnation contact includes: dissolving an iron compound and a transition metal compound in a weakly polar solvent according to the required proportions to form a solution; adding the solution to a carrier source and dispersing it evenly to perform the equal-volume impregnation contact; and then drying and calcining. The aforementioned method has the advantages of high reactivity, good stability, simple synthesis method, and environmental friendliness.

[0039] In this invention, the range of iron compounds that can be selected is relatively wide, and commonly used types can all be used in this invention. For this invention, it is preferred to select at least one of ferrous ammonium sulfate (II), ferrous sulfate (II), ferric sulfate (III), ferric nitrate (III), ferrous oxalate (II), ferrous chloride (II), and ferric chloride (III).

[0040] In this invention, the range of transition metal compounds that can be selected is relatively wide, and commonly used types can all be used in this invention. For this invention, the transition metal compounds are preferably selected from at least one of transition metal chlorides, transition metal bromides, transition metal nitrates, transition metal sulfates, transition metal carbonates, transition metal acetates, transition metal oxalates, and transition metal acetylacetonates.

[0041] In this invention, there are no special requirements for the drying conditions. The drying can be carried out according to conventional drying steps and conditions. According to a preferred embodiment of this invention, the drying conditions include drying at 60-150°C for 4-24 hours, preferably drying at 80-120°C for 8-15 hours.

[0042] In this invention, there are no special requirements for the roasting conditions; they can be carried out according to conventional roasting steps and conditions. According to a preferred embodiment of this invention, the roasting temperature is 350–600°C, preferably 400–500°C; and the roasting time is 2–8 hours, preferably 4–6 hours.

[0043] The catalyst of the present invention is particularly suitable for use in the field of reforming, especially in the field of dry reforming. The present invention provides the application of the catalyst of the present invention in reforming, preferably in dry reforming.

[0044] The catalyst of the present invention is particularly suitable for use in the dry reforming of ethane and carbon dioxide. The present invention provides a method for the dry reforming of ethane and carbon dioxide, wherein the method comprises: reducing the catalyst, and then contacting ethane and carbon dioxide with the reduced catalyst for reaction, wherein the catalyst is the catalyst described in the present invention.

[0045] In this invention, there are no special requirements for the contact reaction conditions, which can be adjusted as needed.

[0046] In this invention, there are no special requirements for the method of reducing the catalyst, and it will not be described in detail here.

[0047] According to a preferred embodiment of the present invention, the method preferably includes: reacting at 400–600°C, preferably 400–500°C, for 20–40 mL / min before the reaction. -1 The mixture is reduced under a reducing atmosphere of H2 for 0.5–2 hours, followed by the introduction of a feed gas of ethane and carbon dioxide. The feed gas composition is C2H6:CO2:N2 = 0.5–1:0.5–1:0–2, with a total flow rate of 10–40 mL / min. -1 The reaction is carried out under normal pressure at a temperature of 500–600°C.

[0048] According to a preferred embodiment of the present invention, the present invention provides a method for preparing an ethane and carbon dioxide dry reforming catalyst, wherein iron and transition metal active components are loaded onto a variable valence oxide and / or composite oxide support by a one-step equal-volume impregnation method, and the polarity or weighted polarity (in molar fraction) of the impregnation solvent is weakly polar.

[0049] According to a preferred embodiment of the present invention, an iron precursor and a transition metal active component precursor are dissolved in a certain proportion of a weakly polar mixed solvent. The resulting solution is slowly added to a support and thoroughly stirred and mixed. After drying at a certain temperature and calcination, a multi-metal supported catalyst with uniform distribution of active components can be obtained.

[0050] According to a preferred embodiment of the present invention, an ethane and carbon dioxide dry reforming catalyst is provided, comprising iron and transition metal active components, wherein the transition metal active components specifically include one or more selected from ruthenium (Ru), rhodium (Rh), rhenium (Re), osmium (Os), iridium (Ir), and platinum (Pt); the support is a variable valence oxide or composite oxide, specifically including at least one selected from titanium oxide (TiO2), cerium oxide (CeO2), and composite oxides formed with aluminum oxide (Al2O3), magnesium oxide (MgO), zirconium oxide (ZrO2), and silicon oxide (SiO2); the reduction peak temperature of the active metal on the catalyst surface in a hydrogen programmed temperature reduction test is less than or equal to the reduction peak temperature of the sample with a corresponding active component dispersion of 50%; scanning transmission microscopy (STEM) images and energy dispersive X-ray spectroscopy (EDS mapping) images show the active components dispersed on the surface of the composite oxide support, wherein the active components are dispersed on the surface of the cerium-aluminum composite oxide support, and the dispersion of the active components is 67-96%.

[0051] This invention also provides a dry reforming reaction of ethane and carbon dioxide, using the catalyst described above or prepared by the above method. The specific steps of the dry reforming reaction of ethane and carbon dioxide are as follows:

[0052] (1) The catalyst is reduced in a hydrogen atmosphere at a reduction temperature of 350-700℃, preferably 400-500℃, and for a reduction time of 0.5-4h, preferably 0.5-2h.

[0053] (2) The reaction is carried out in a fixed-bed reactor at atmospheric pressure, with a reaction temperature of 550–750℃, preferably 500–600℃. The feed gas is a mixture of ethane, carbon dioxide, and nitrogen, with a total flow rate of 5–120 mL·min. -1 Preferably 10-40 mL·min -1 The volume fraction of ethane is 25-50%, the volume fraction of carbon dioxide is 25-50%, and the remainder is nitrogen balance gas.

[0054] The present invention will be further illustrated by the following embodiments, but the application of the present invention is not limited to these embodiments.

[0055] The calculation method for ethane conversion rate is: (ethane inlet velocity - ethane outlet velocity) ÷ ethane inlet velocity × 100%.

[0056] The calculation method for CO selectivity is: 1 - ∑ non-CO product flow rate ÷ (ethane inlet flow rate - ethane outlet flow rate) × 100%.

[0057] In this invention, the following Figure 1 The images shown are scanning transmission microscopy (STEM) images (1a) and energy dispersive X-ray spectroscopy (EDS mapping) images (1b-1f) of the active metals in catalyst A of Example 1 dispersed on the surface of the support. Among them, 1b is a stacked distribution map of each element, 1c is a distribution map of Ce, 1d is a distribution map of Al, 1e is a distribution map of Fe, and 1f is a distribution map of Pt.

[0058] Figure 2 Images showing the hydrogen temperature-programmed reduction (H2-TPR) of the active metals on the support surface of catalyst A in Example 1 and catalyst G in Comparative Example 1, generated by... Figure 2 It can be seen that the reduction peak temperature of the surface active metal of catalyst A in the hydrogen programmed temperature reduction test is lower than that of the contrast agent catalyst G.

[0059] Example 1

[0060] Dissolve 0.04 mmol of ferric nitrate and 0.20 mmol of chloroplatinic acid in a suitable amount of ethanol-isobutanol mixed solvent with a solvent weighted polarity of 3.9 (where the molar fraction of ethanol is 69.2%), and add 1.090 g of cerium-aluminum composite oxide (CeAlO). x Catalyst A was obtained by impregnating the support with an equal volume for 1 hour, drying at 80°C for 15 hours, and calcining at 400°C for 6 hours, with a dispersion of 96% for the iron-platinum active components. The proportion of metals in catalyst A was determined by ICP-AES: the molar ratio of platinum to iron in catalyst A was 1:0.2 (molar percentage). Figure 1 The STEM image shows that the iron-platinum active components (1e, 1f) of catalyst A are dispersed on the surface of the cerium-aluminum composite oxide support (1c, 1d) in the region shown in 1a. Figure 2 The H2-TPR image of catalyst A shows that its reduction peak temperature is lower than that of the sample with 50% dispersion of the active component. (STEM image) Figure 1 a) and energy-dispersive X-ray spectral surface scanning ( Figure 1b)(EDS mapping) shows that the active metal is dispersed on the surface of the support.

[0061] The reactivity of catalyst A with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and a temperature of 500℃ for 2 hours. The ethane conversion rate of catalyst A was 30.6%, the CO selectivity was 97.3%, and the main product was syngas.

[0062] After 12 hours of reaction, the ethane conversion rate was 28.7%, the CO selectivity was 97.5%, and the main product was syngas.

[0063] Example 2

[0064] 0.04 mmol of ferric chloride and 0.10 mmol of iridium acetylacetone were dissolved in a suitable amount of ethanol-acetone mixed solvent with a solvent weighted polarity of 4.7 (where the molar fraction of ethanol was 63.6%). Then, 1.255 g of cerium-zirconium composite oxide (CeZrO) was added. x Catalyst B was obtained by impregnating the support with an equal volume for 1 hour, drying at 100℃ for 12 hours, and calcining at 450℃ for 5 hours. The dispersion of the iron-iridium active component was 85%, and the iron-iridium active component was dispersed on the surface of the cerium-zirconium composite oxide. The proportion of metals in catalyst B was determined by ICP-AES: the molar ratio of iridium to iron in catalyst B was 1:0.4 (molar percentage).

[0065] The reactivity of catalyst B with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 450 °C for 30 mL / min. -1 The reaction was carried out under a H2 atmosphere for 1 hour, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:1. The reaction was conducted at atmospheric pressure and a reaction temperature of 550℃ for 2 hours. The ethane conversion rate of catalyst B was 29.4%, the CO selectivity was 98.2%, and the main product was syngas.

[0066] After 12 hours of reaction, the ethane conversion rate was 26.9%, the CO selectivity was 98.5%, and the main product was syngas.

[0067] Example 3

[0068] 0.03 mmol of ferrous sulfate and 0.05 mmol of rhodium chloride were dissolved in an appropriate amount of ethanol-water mixed solvent with a solvent weighted polarity of 5.4 (where the molar fraction of ethanol was 81.4%). Then, 0.959 g of titanium-magnesium composite oxide (MgTiO) was added.x Catalyst C was obtained by impregnating the support with an equal volume for 1 hour, drying at 120℃ for 8 hours, and calcining at 500℃ for 4 hours. The dispersion of the iron-rhodium active component was 76%, and the iron-rhodium active component was dispersed on the surface of the titanium-magnesium composite oxide. The proportion of metals in catalyst C was determined by ICP-AES: the molar ratio of rhodium to iron in catalyst C was 1:0.6 (molar percentage).

[0069] The reactivity of catalyst C with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 500 °C for 20 mL / min. -1 The reaction was carried out under a H2 atmosphere for 0.5 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:0. The reaction was conducted at atmospheric pressure and 600℃ for 2 hours. The ethane conversion rate of catalyst C was 28.6%, the CO selectivity was 98.9%, and the main product was syngas.

[0070] After 12 hours of reaction, the ethane conversion rate was 25.6%, the CO selectivity was 98.7%, and the main product was syngas.

[0071] Example 4

[0072] 0.04 mmol of ferric nitrate and 0.20 mmol of chloroplatinic acid were dissolved in an appropriate amount of ethanol-water mixed solvent with a solvent weighted polarity of 6.0 (where the molar fraction of ethanol was 71.2%). Then, 1.090 g of cerium-aluminum composite oxide (CeAlO) was added. x Catalyst D was obtained by impregnating the support with an equal volume for 1 hour, drying at 80℃ for 15 hours, and calcining at 400℃ for 6 hours. The dispersion of the iron-platinum active component was 69%, and the iron-platinum active component was dispersed on the surface of the cerium-aluminum composite oxide. The proportion of metals in catalyst D was determined by ICP-AES: the molar ratio of platinum to iron in catalyst D was 1:0.2 (molar percentage).

[0073] The reactivity of catalyst D with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and a reaction temperature of 500℃ for 2 hours. The ethane conversion rate of catalyst D was 27.8%, the CO selectivity was 84.2%, and the main product was syngas.

[0074] After 12 hours of reaction, the ethane conversion rate was 24.7%, the CO selectivity was 85.3%, and the main product was syngas.

[0075] Example 5

[0076] Dissolve 0.10 mmol of ferric nitrate and 0.10 mmol of chloroplatinic acid in a suitable amount of ethanol-isobutanol mixed solvent with a solvent weighted polarity of 3.9 (where the molar fraction of ethanol is 69.2%), and add 0.852 g of cerium-aluminum composite oxide (CeAlO). x Catalyst E was obtained by impregnating the support with an equal volume for 1 hour, drying at 80°C for 15 hours, and calcining at 400°C for 6 hours. The dispersion of the iron-platinum active component was 67%, and the iron-platinum active component was dispersed on the surface of the cerium-aluminum composite oxide. The proportion of metals in catalyst E was determined by ICP-AES: the molar ratio of platinum to iron in catalyst E was 1:1 (molar percentage).

[0077] The reactivity of catalyst E with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and a reaction temperature of 500℃ for 2 hours. The ethane conversion rate of catalyst E was 27.1%, the CO selectivity was 80.7%, and the main product was syngas.

[0078] After 12 hours of reaction, the ethane conversion rate was 23.6%, the CO selectivity was 83.3%, and the main product was syngas.

[0079] Example 6

[0080] 0.08 mmol of ferric nitrate and 0.40 mmol of chloroplatinic acid were dissolved in a suitable amount of ethanol-isobutanol mixed solvent with a solvent weighted polarity of 3.9 (where the molar fraction of ethanol was 69.2%). Then, 0.817 g of cerium-aluminum composite oxide (CeAlO) was added. x Catalyst F was obtained by impregnating the support with an equal volume for 1 hour, drying at 80℃ for 15 hours, and calcining at 400℃ for 6 hours. The dispersion of the iron-platinum active component was 71%, and the iron-platinum active component was dispersed on the surface of the cerium-aluminum composite oxide. The proportion of metals in catalyst F was determined by ICP-AES: the molar ratio of platinum to iron in catalyst F was 1:0.2 (molar percentage).

[0081] The reactivity of catalyst F with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and a reaction temperature of 500℃ for 2 hours. The ethane conversion rate of catalyst F was 28.2%, the CO selectivity was 90.5%, and the main product was syngas.

[0082] After 12 hours of reaction, the ethane conversion rate was 24.1%, the CO selectivity was 92.7%, and the main product was syngas.

[0083] Comparative Example 1

[0084] 0.04 mmol of ferric nitrate and 0.20 mmol of chloroplatinic acid were dissolved in an appropriate amount of acetone-water mixed solvent with a solvent weighted polarity of 6.5 (where the molar fraction of acetone was 77.1%). Then, 1.090 g of cerium-aluminum composite oxide (CeAlO) was added. x Catalyst G was obtained by impregnating the support with an equal volume for 1 hour, drying at 80℃ for 15 hours, and calcining at 400℃ for 6 hours. The dispersion of the iron-platinum active component was 50%, and the iron-platinum active component was concentrated on the surface of the cerium-aluminum composite oxide. The proportion of metals in catalyst G was determined by ICP-AES: the molar ratio of platinum to iron in catalyst G was 1:0.2 (molar percentage).

[0085] The reactivity of catalyst G with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and 500℃. The catalyst G achieved an ethane conversion rate of 24.1% and a CO selectivity of 63.9%, with syngas as the main product.

[0086] After 12 hours of reaction, the ethane conversion rate was 19.5%, the CO selectivity was 61.7%, and the main product was syngas.

[0087] Comparative Example 2

[0088] 0.04 mmol of ferric nitrate and 0.20 mmol of chloroplatinic acid were dissolved in 10 mL of an ethanol-isobutanol mixed solvent with a solvent weighted polarity of 3.9 (where the molar fraction of ethanol was 69.2%). Then, 1.090 g of cerium-aluminum composite oxide (CeAlO) was added using an excess impregnation method. x Catalyst H was obtained by impregnating the support for 1 hour, drying at 80℃ for 15 hours, and calcining at 400℃ for 6 hours. The iron-platinum active component dispersion was 65%, and the iron-platinum active component was concentrated on the surface of the cerium-aluminum composite oxide. The metal ratio in catalyst H was determined by ICP-AES: the molar ratio of platinum to iron in catalyst H was 1:0.2 (molar percentage). The H2-TPR reduction peak temperature of catalyst H was higher than that of the sample with 50% active component dispersion.

[0089] The reactivity of catalyst H with ethane and carbon dioxide was tested in a fixed-bed atmospheric pressure microreactor. The catalyst dosage was 100 mg, and the reaction was initially carried out at 400 °C for 40 mL / min. -1 The reaction was carried out under a H2 atmosphere for 2 hours, followed by the introduction of a feed gas with a composition of C2H6:CO2:N2 = 1:1:2. The reaction was conducted at atmospheric pressure and a reaction temperature of 500℃ for 2 hours. The ethane conversion rate of catalyst H was 25.7%, the CO selectivity was 69.5%, and the main product was syngas.

[0090] After 12 hours of reaction, the ethane conversion rate was 21.6%, the CO selectivity was 70.4%, and the main product was syngas.

[0091] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A reforming catalyst, characterized in that, The catalyst contains a support and a reforming active component loaded on the support. The reforming active component includes iron and transition metals, with a molar ratio of transition metal to iron of 1:0.2~1. The reduction peak temperature of the active metal on the catalyst surface in a hydrogen programmed temperature reduction test is less than or equal to the reduction peak temperature of the sample with a corresponding active component dispersion of 50%. And / or the active metal is dispersed on the surface of the support. The dispersion of the active ingredient is 67-96%; The catalyst comprises 90-99.5 parts of support and 0.5-10 parts of reforming active component based on oxides, by mass fraction of the catalyst. The transition metal is selected from one or more of ruthenium, iridium, rhodium, rhenium, osmium, and platinum; The reduction peak temperature of the catalyst surface-active metal in the hydrogen programmed temperature reduction test is less than or equal to 210°C.

2. The catalyst according to claim 1, wherein, The catalyst contains 0.5-4 parts by mass of reforming active components, calculated as oxides.

3. The catalyst according to claim 2, wherein, The molar ratio of transition metal elements to iron is 1:0.2~0.

6.

4. The catalyst according to claim 1, wherein, The carrier is selected from one or more oxides or composite oxides formed from titanium, cerium, aluminum, magnesium, zirconium, and silicon.

5. The catalyst according to claim 1, wherein, The transition metal is selected from one or more of iridium, rhodium, and platinum.

6. A method for preparing the catalyst according to any one of claims 1-5, wherein, The method includes: impregnating and contacting a solution containing a reforming active component source with a carrier source in an equal volume, wherein the polarity of the solvent in the solution or the weighted polarity in molar fractions is weakly polar, followed by drying and calcination; The polarity of the solvent in the solution is in the range of 3.9 to 6.

0.

7. The preparation method according to claim 6, wherein, The polarity of the solvent in the solution is in the range of 3.9 to 5.

4.

8. The preparation method according to claim 6, wherein, The solvent is selected from at least one of water, methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, isobutanol, acetone, formic acid, acetic acid, ethyl acetate, N,N-dimethylformamide, acetonitrile, cyclohexane, and petroleum ether.

9. The preparation method according to claim 8, wherein, The solvent is selected from one or more of water, ethanol, isobutanol, and acetone.

10. The preparation method according to claim 6, wherein, The steps of the equal-volume impregnation contact include: dissolving iron compounds and transition metal compounds in a weakly polar solvent according to the required ratio to form a solution, adding the solution to a carrier source and dispersing it evenly to perform the equal-volume impregnation contact, followed by drying and calcination.

11. The preparation method according to claim 10, wherein, The iron compound is selected from at least one of ferrous ammonium sulfate, ferrous sulfate, ferric sulfate, ferric nitrate, ferrous oxalate, ferrous chloride, and ferric chloride; and / or The transition metal compound is selected from at least one of transition metal chlorides, transition metal bromides, transition metal nitrates, transition metal sulfates, transition metal carbonates, transition metal acetates, transition metal oxalates, and transition metal acetylacetonates.

12. The preparation method according to claim 10, wherein, The drying conditions include: drying at 60~150°C for 4~24 h; and / or The roasting temperature is 350~600°C; the roasting time is 2~8 h.

13. The preparation method according to claim 12, wherein, The drying conditions include: drying at 80~120°C for 8~15 h; and / or The roasting temperature is 400~500°C; the roasting time is 4~6 h.

14. The use of the catalyst according to any one of claims 1-5 in reforming.

15. The application according to claim 14, wherein, The reforming is dry reforming.

16. A method for dry reforming ethane and carbon dioxide, wherein, The method includes: The catalyst is reduced, and then ethane and carbon dioxide are reacted with the reduced catalyst. The catalyst is the catalyst described in any one of claims 1-5.

17. The method according to claim 16, wherein, The method includes: preheating the reaction at 400–600°C for 20–40 mL / min. -1 The mixture is reduced under a reducing atmosphere of H2 for 0.5–2 hours, followed by the introduction of a feed gas of ethane and carbon dioxide. The feed gas composition is C2H6:CO2:N2 = 0.5–1:0.5–1:0–2, with a total flow rate of 10–40 mL / min. -1 The reaction is carried out under normal pressure and at a temperature of 500~600°C.

18. The method according to claim 17, wherein, The method includes: reduction at 400-500°C before the reaction.

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