Catalyst for hydrogen production from hydrogen-containing compounds, method for producing and using the same, and method for hydrogen production from hydrogen-containing compounds

Abstract

The present application relates to the technical field of catalyst preparation, and discloses a catalyst for hydrogen production from hydrogen-containing compounds, a preparation method and application thereof, and a hydrogen production method from hydrogen-containing compounds. The catalyst comprises a carrier, a dehydrogenation active component and halogen supported on the carrier; the dehydrogenation active component comprises noble metal oxide and variable valence metal oxide; the content of the dehydrogenation active component is 0.3-2 wt% based on the total mass of the carrier; the content of halogen in terms of elements is not higher than 0.2 wt% based on the total mass of the carrier; and the halogen comprises bromine and chlorine. The catalyst has high low-temperature catalytic activity and hydrogen production efficiency, and is not prone to deactivation.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to a catalyst for producing hydrogen from hydrogen-containing compounds, its preparation method and application, and a method for producing hydrogen from hydrogen-containing compounds. Background Technology

[0002] Hydrogen fuel cell technology will play an increasingly important role. However, the high cost of storing pure hydrogen directly limits its application, especially in mobile or stationary power sources. Therefore, it is necessary to explore new and efficient on-line hydrogen production fuel cell technologies to meet the energy demands of a future low-carbon hydrogen society. On-line hydrogen production technologies mainly include solid-state hydrogen storage and compound hydrogen storage. Solid-state hydrogen storage produces high-purity hydrogen but has low storage density. Compound hydrogen storage mainly includes technologies using organic liquids, liquid ammonia, and methanol.

[0003] The efficiency of online hydrogen production technology is closely related to the hydrogen production equipment and the catalysts used to match it. High-performance dehydrogenation catalysts, in addition to affecting the reaction itself, can also improve the operating cycle of the equipment, the heat transfer efficiency during use, and the overall system efficiency, thus significantly enhancing the competitiveness of the technology.

[0004] Regarding dehydrogenation catalysts for hydrogen-containing compounds, CN111686718A provides a cyclohexane dehydrogenation catalyst and its preparation method. The catalyst is a metal-supported catalyst, comprising a metal active component and a support. The metal active component is Pt, and the support is γ-Al2O3. This method increases the steric hindrance of the metal-supported compound in the impregnation solution through ammonia complexation. Moreover, alkaline conditions can further reduce the loading rate of the active metal, prevent metal particle agglomeration, and improve the dispersibility and uniformity of the catalyst active component. The dehydrogenation catalyst provided by this method can achieve a cyclohexane conversion rate of 99.5% and a benzene selectivity of over 99% in a laboratory cyclohexane dehydrogenation device. However, its dehydrogenation temperature is as high as 420-450℃, resulting in stringent material selection and high system energy consumption.

[0005] CN113546651A discloses a phosphorus-modified carbon-based catalyst, its preparation method, and its application. The catalyst is modified with a phosphorus-containing compound, and the phosphorus content in the catalyst is 0.3-10% by mass of the total catalyst. The phosphorus-containing compound is selected from one or more of phosphoric acid, phosphates, phenylphosphonic acid, phytic acid, triphenylphosphine, triphenylphosphine, and tributylphosphine. The phosphorus-modified carbon-based catalyst prepared by this method has widely available and inexpensive raw materials, and the preparation methods are diverse and simple. It exhibits excellent catalytic activity and product selectivity in the cyclohexane dehydrogenation reaction and can be used as a dehydrogenation catalyst for the cyclohexane-benzene hydrogen storage system. However, its dehydrogenation temperature is as high as 475-550℃, resulting in high system energy consumption and low efficiency.

[0006] Highly integrated equipment refers to a type of integrated equipment whose size and weight are lower than those of large chemical plants. If both of the above catalysts need to be operated at high temperatures, the external energy required is high, and the heat loss is significant, their use in highly integrated equipment will lead to low system efficiency. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing catalysts for hydrogen production from hydrogen-containing compounds, which require high temperatures during hydrogen production and result in low system efficiency when used in highly integrated equipment. This invention provides a catalyst for hydrogen production from hydrogen-containing compounds, its preparation method, its application, and a method for hydrogen production from hydrogen-containing compounds. The catalyst prepared by this method not only reduces the operating temperature of the catalyst but also exhibits high dehydrogenation efficiency.

[0008] To achieve the above objectives, a first aspect of the present invention provides a catalyst for the production of hydrogen from hydrogen-containing compounds, the catalyst comprising a support and a dehydrogenation active component and a halogen supported on the support; wherein the dehydrogenation active component comprises a noble metal oxide and a variable-valence metal oxide; the content of the dehydrogenation active component is 0.3-2.5 wt% based on the total mass of the support; and the halogen content, based on the total mass of the support, is not higher than 0.2 wt% (elementally); the halogen comprises bromine and chlorine.

[0009] The second aspect of the present invention provides a method for preparing the above-mentioned catalyst for hydrogen production from hydrogen-containing compounds. The method includes: a support being first contacted with a first solution containing a dehydrogenation active component source, optionally being first dried, and then being second contacted with a second solution containing a halogen source, followed by a second drying and calcination.

[0010] The third aspect of the present invention provides the application of the above-mentioned catalyst for hydrogen production from hydrogen-containing compounds in the production of hydrogen from hydrogen-containing compounds.

[0011] A fourth aspect of the present invention provides a method for producing hydrogen from hydrogen compounds, the method comprising reacting the above-mentioned catalyst for producing hydrogen from hydrogen compounds or the catalyst for producing hydrogen from hydrogen compounds prepared by the above-mentioned preparation method in contact under conditions for dehydrogenation of hydrogen-containing compounds.

[0012] Compared with the prior art, the present invention has at least the following beneficial effects:

[0013] The catalyst of this invention not only has high low-temperature catalytic activity and hydrogen production efficiency, but is also not easily deactivated. In addition, by controlling the specific composition and macroscopic properties of the catalyst, this invention enables the catalyst to be applied to the hydrogen production process of hydrogen-containing compounds in highly integrated equipment. After application, the catalyst has high catalytic activity at a lower temperature, which can not only improve the operating cycle of the device and the heat transfer efficiency during use, but also improve the system efficiency. Detailed Implementation

[0014] 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.

[0015] Existing technologies do not specify the operating temperature requirements for catalysts used in hydrogen production from hydrogen-containing compounds. Generally, existing catalysts for hydrogen production from hydrogen-containing compounds operate at temperatures above 400°C. This leads to reduced catalyst lifespan, higher system energy consumption, and a lower dehydrogenation rate. The present invention provides a specific catalyst for hydrogen production from hydrogen-containing compounds with a lower operating temperature, which can effectively reduce system energy consumption and extend catalyst lifespan. Furthermore, at lower operating temperatures, the catalyst can also improve the conversion rate and dehydrogenation rate of hydrogen-containing compounds.

[0016] A first aspect of the present invention provides a catalyst for producing hydrogen from hydrogen-containing compounds, the catalyst comprising a support and a dehydrogenation active component and a halogen supported on the support; wherein the dehydrogenation active component comprises noble metal oxides and variable-valence metal oxides; the content of the dehydrogenation active component is 0.3-2.5 wt% based on the total mass of the support; the halogen content, based on the total mass of the support, is not higher than 0.2 wt%; the halogen comprises bromine and chlorine.

[0017] In this invention, the inventors discovered that the presence of no more than 0.2 wt% halogen in the catalyst interacts with the dehydrogenation active component, increasing the catalyst's low-temperature catalytic activity. Furthermore, the catalyst exhibits not only high hydrogen production efficiency during use but also resistance to deactivation. The inventors hypothesize that halogens, especially those containing bromine and chlorine, interact with noble metal oxides and variable-valence metal oxides on the support. This interaction with the support increases the active sites on the catalyst and reduces the potential for noble metal poisoning.

[0018] According to the present invention, in some embodiments, the halogen content, based on the total mass of the carrier, is 0.01-0.2 wt%, preferably 0.1-0.2 wt%. Using the aforementioned specific halogen content can achieve a good synergistic effect with the dehydrogenation active component, exhibiting excellent hydrogen production performance.

[0019] According to some preferred embodiments of the present invention, the mass ratio of bromine to chlorine, based on elemental composition, is 1:(1-10), preferably 1:(2-6). Under the aforementioned embodiments, the catalytic activity and hydrogen production efficiency of the catalyst can be further increased.

[0020] According to the present invention, the content of the dehydrogenation active component is 0.7-2.3 wt%. The aforementioned embodiments increase the low-temperature catalytic activity and hydrogen production efficiency of the catalyst.

[0021] According to the present invention, based on the total mass of the support, in some embodiments, the content of the noble metal oxide is greater than 0.1 wt%, preferably 0.2-0.8 wt%. By employing the aforementioned embodiments, the adsorption of hydrogen-containing compounds by the catalyst can be increased, while simultaneously increasing the dehydrogenation effect of the active component on the hydrogen-containing compounds.

[0022] According to the present invention, in some embodiments, the content of the variable valence metal oxide is not less than 0.01 wt%, preferably 0.01-2 wt%, and more preferably 0.5-1.5 wt%. By employing the aforementioned embodiments, the low-temperature hydrogen production efficiency of the catalyst can be increased. The inventors speculate that the variable valence metal oxide can synergistically interact with noble metals and halogens, especially on the support of the present invention. The preferred range of variable valence metal oxide content can, to a certain extent, avoid the defect of variable valence metal oxide causing a loss in the specific surface area of ​​the support.

[0023] According to the present invention, the type of noble metal oxide is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the noble metal oxide is selected from one or more of platinum oxide, palladium oxide, ruthenium oxide, rhodium oxide, and iridium oxide, preferably platinum oxide. Under the action of the aforementioned noble metal oxide, the low-temperature catalytic activity of the catalyst can be increased.

[0024] According to the present invention, it is understood that a variable-valence metal oxide refers to a metal that can have multiple valences when forming different compounds. The type of variable-valence metal oxide is not limited as long as the objectives of the present invention are achieved. In some embodiments, the variable-valence metal oxide includes at least two of molybdenum oxide, iron oxide, copper oxide, cobalt oxide, vanadium oxide, chromium oxide, manganese oxide, and tungsten oxide. Using any two of the aforementioned variable-valence metal oxides to interact can better promote the interaction between the variable-valence metal oxide and noble metals or halogens on the support, thereby better promoting the activity of the catalyst.

[0025] According to the present invention, in some preferred embodiments, the variable valence metal oxide includes at least two of molybdenum oxide, iron oxide, copper oxide, and cobalt oxide. The noble metal oxide and the aforementioned preferred variable valence metal oxide can interact better on the support. Simultaneously, during catalyst use, hydrogen-containing compounds can be better adsorbed onto the catalyst and synergistically interact with the noble metal, the preferred variable valence metal oxide, and halogens, increasing the low-temperature catalytic activity of the catalyst. Existing catalysts containing noble metal oxides, especially platinum oxide, suffer from the drawback of easy catalyst deactivation. However, in the present invention, the use of variable valence metal oxides, especially the aforementioned two preferred variable valence metal oxides, interacts with noble metal oxides and halogens, making the catalyst less prone to deactivation.

[0026] According to some preferred embodiments of the present invention, the variable valence metal oxide contains 20-50 wt% iron oxide.

[0027] According to the present invention, the specific type of support is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the support is selected from at least one of γ-Al2O3, silicon oxide, magnesium aluminum spinel, and MCM-41; in some preferred embodiments, the support is γ-Al2O3. The aforementioned preferred embodiments facilitate better interaction between noble metal oxides, variable valence metal oxides, halogens, and the support to achieve the purpose of the present invention.

[0028] According to the present invention, the shape of the carrier is not particularly limited, but in some embodiments, the shape of the carrier is spherical and / or toothed.

[0029] According to the present invention, it is understood that the shape of the catalyst depends on the shape of the support. In addition, spherical and toothed spherical shapes can be used alone or mixed in any proportion in the present invention. The present invention has no special requirements for this. The inventors have found that when the support shape is spherical and / or toothed spherical, the catalyst can produce hydrogen better at low temperatures. The inventors speculate that the catalyst supported by this shape is beneficial to reducing the internal diffusion hindrance effect in the hydrogen production process and increasing the catalyst's adsorption capacity for hydrogen-containing compounds. At the same time, it can also make the material have a better mass transfer effect when in contact with the catalyst.

[0030] According to the present invention, in some embodiments, the diameter of the support is 2-6 mm. By employing the aforementioned embodiments, better low-temperature catalytic activity of the catalyst can be achieved.

[0031] According to the present invention, in some embodiments, the pore volume of the carrier is greater than 0.2 cm. 3 / g, preferably 0.5-0.8cm 3 / g. In the aforementioned embodiments, the active sites of the catalyst can be increased, thereby increasing the low-temperature catalytic activity of the catalyst.

[0032] According to the present invention, in some embodiments, the proportion of pores of 5-8 nm in the support is greater than 80%, preferably 85-95%. Using the aforementioned embodiments can increase the low-temperature catalytic activity and hydrogen production efficiency of the catalyst.

[0033] According to the present invention, in some embodiments, the specific surface area of ​​the carrier is greater than 180 m². 2 / g, preferably 210-280m 2 / g. By adopting the aforementioned implementation method, the adsorption of the catalyst on the material can be increased, thereby achieving a higher hydrogen production efficiency.

[0034] According to the present invention, in some embodiments, the crushing strength of the carrier is not less than 100 N / cm, preferably 100-200 N / cm.

[0035] The second aspect of the present invention provides a method for preparing the above-mentioned catalyst for hydrogen production from hydrogen-containing compounds, the method comprising: first contacting a support with a first solution of a dehydrogenation active component source, optionally performing a first drying, then second contacting the support with a second solution of a halogen source, and then sequentially performing a second drying and calcination.

[0036] According to the present invention, it is understood that the first solution containing the dehydrogenation active component source (i.e., containing a noble metal source and a variable valence metal source) refers to a solution in which the noble metal source, the variable valence metal source, and optionally other components are dissolved using a first solvent; the second solution containing the halogen source refers to a solution in which the halogen source and optionally other components are dissolved using a second solvent; wherein, the types of the first and second solvents can be selected as needed, such as water. Furthermore, in preparing the first and second solutions, heating can be performed as needed to form the corresponding solutions, or mixing can be done using water at a certain temperature (e.g., 50-90°C) to form the corresponding solutions.

[0037] In this invention, the catalyst performance can be better enhanced by sequentially contacting the support with a first solution containing a noble metal source and a variable valence metal source, and a second solution containing a halogen source. The inventors speculate that the noble metal source and the variable valence metal source first occupy sites on the support, and then the halogen source is used to modify the support to a certain extent and further occupy sites, which can further increase the active sites and their stability.

[0038] According to the present invention, the concentration of the dehydrogenating active component source in the first solution containing the dehydrogenating active component source can be selected as needed. In the study, it was found that almost all the active sources in the dehydrogenating active component can be loaded on the support. Therefore, there is no special limitation on the concentration of the dehydrogenating active component source in the first solution containing the dehydrogenating active component source. For example, the content of the dehydrogenating active component source in the first solution containing the dehydrogenating active component source is 0.1-1 wt%.

[0039] According to the present invention, it is understood that the noble metal source refers to a form existing before obtaining the noble metal oxide. As long as the purpose of the present invention can be achieved, the type of the noble metal source is not particularly limited, such as the chloride salt of noble metal, the nitrate salt of noble metal, etc.; the variable valence metal source that provides the variable valence metal oxide is a form existing before obtaining the variable valence metal oxide. As long as the purpose of the present invention can be achieved, the specific type of variable valence metal source can be selected as needed, such as the nitrate salt of variable valence metal or the chloride of variable valence metal.

[0040] According to the present invention, the concentration of the halogen source in the second solution containing the halogen source can be selected as needed. In the experiment, the inventors found that the loss of halogen in the halogen source was relatively large during the preparation process, so it is necessary to increase the concentration of the halogen source in the second solution containing the halogen source. In some embodiments, the concentration of the halogen source in the second solution containing the halogen source is 15-30 wt%.

[0041] According to the present invention, the type of halogen source is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the halogen source includes a quaternary ammonium salt that provides halogen and / or a halogen compound containing at least one halogen and hydrogen.

[0042] According to the present invention, in some preferred embodiments, the halogen source comprises a quaternary ammonium salt providing halogens and a halogen compound containing at least one halogen and hydrogen. The halogen source in this invention can, to a certain extent, improve the dispersibility of noble metal sources and variable valence metal sources on the support. The inventors have found that the interaction between the aforementioned quaternary ammonium salt and halogen compound can better improve the low-temperature catalytic activity and hydrogen production efficiency of the catalyst, while also making the catalyst less prone to deactivation. The inventors hypothesize that, on the one hand, the synergistic effect between the quaternary ammonium salt and the halogen compound containing at least one halogen and hydrogen can better disperse the noble metal salt and variable valence metal salt on the support to form active sites and exposed active center structures; on the other hand, the interaction between the two on the support can provide a special microenvironment, allowing the noble metal source and variable valence metal source already occupied on the support to further exert a certain effect in the halogen-containing system, improving the morphological characteristics of the catalyst and thus affecting the catalyst's performance.

[0043] According to the present invention, the amount of quaternary ammonium salt and halogen compound added can be selected as needed, as long as the objective of the present invention can be achieved. In some embodiments, the weight ratio of the quaternary ammonium salt providing the halogen to the halogen compound containing at least one halogen and hydrogen is 1:(1-10), preferably 1:(1.5-5). By employing the aforementioned embodiments, the quaternary ammonium salt and halogen compound can better achieve synergistic effects, while further avoiding the defect that the quaternary ammonium salt may cover part of the active center and reduce the catalytic effect.

[0044] According to the present invention, in some embodiments, the quaternary ammonium salt comprises C12-C20 alkyltrimethylammonium halide and / or C12-C20 alkyldimethylbenzylammonium halide. In the aforementioned embodiments, the quaternary ammonium salt with this structure synergistically promotes the dispersion of the dehydrogenation active component and provides a suitable microenvironment for the system.

[0045] According to the present invention, in some embodiments, the quaternary ammonium salt comprises C14-C16 alkyltrimethylammonium halide and / or C14-C16 alkyldimethylbenzylammonium halide. The aforementioned embodiments can further increase the low-temperature catalytic activity and hydrogen production efficiency of the catalyst.

[0046] According to some embodiments of the present invention, the halogen compound is selected from one or more of perchloric acid, hypochlorous acid, hydrochloric acid, hydrogen bromide, hydrogen iodide, dichloroisohydrouric acid, trichloroisohydrouric acid, chloroacetic acid, and acyl chloride.

[0047] According to some preferred embodiments of the present invention, the halogen compound is selected from hydrochloric acid and / or dichloroisohydrouric acid.

[0048] According to the present invention, in some preferred embodiments, the halogen source includes C14-C16 alkyltrimethylammonium bromide and / or C14-C16 alkyldimethylbenzylammonium bromide, and includes hydrochloric acid and / or dichloroisohydrouric acid. Using the aforementioned embodiments, the various components work synergistically, not only contributing to better formation of the second solution, but also improving the phase characteristics of the catalyst, thereby affecting the catalyst's performance.

[0049] According to the present invention, the manner of the first contact and the second contact is not limited as long as the purpose of the present invention can be achieved. In some embodiments, the manner of the first contact and the second contact is selected from one of wet dipping, spraying, spraying or brushing.

[0050] According to some preferred embodiments of the present invention, the first contact is made by spraying.

[0051] According to the present invention, the spraying conditions are not limited as long as the purpose of the present invention can be achieved. In some embodiments, the spraying conditions include a spraying temperature of 40-80°C. By adopting the aforementioned embodiments, better uniformity of spraying can be achieved, allowing the active ingredients to be more evenly distributed on the carrier.

[0052] According to the present invention, in order to enable the first solution to better contact the carrier, in some embodiments, the spraying conditions include: a spraying pressure of 0.01-0.08 kPaG.

[0053] According to the present invention, in some embodiments, the spraying conditions include: the main rotation speed of the spraying machine is 5-10 r / min during spraying.

[0054] According to some preferred embodiments of the present invention, the second contact method is a brushing method.

[0055] According to the present invention, in some embodiments, the conditions for the brushing method include: the brushing temperature is 40-80°C.

[0056] According to the present invention, there are no special restrictions on the drying and calcination conditions during catalyst preparation, as long as the purpose of the present invention can be achieved. In some embodiments, the temperatures of the first drying and the second drying are each 80-120°C.

[0057] According to some embodiments of the present invention, the drying time for the first drying and the drying time for the second drying are each 2-15 hours.

[0058] According to the present invention, in some embodiments, the calcination temperature is 400-600°C.

[0059] According to the present invention, in some embodiments, the roasting time is 2-10 hours.

[0060] The third aspect of the present invention provides the application of the above-mentioned catalyst for hydrogen production from hydrogen-containing compounds or the catalyst prepared by the above-mentioned method for hydrogen production from hydrogen-containing compounds in the production of hydrogen from hydrogen-containing compounds.

[0061] According to the present invention, in some embodiments, the catalyst is used at a temperature of 280-320°C.

[0062] According to the present invention, as mentioned above, existing catalysts have drawbacks such as excessively high operating temperatures, short lifespan, and high energy consumption. The catalyst of the present invention not only has a lower operating temperature in the application of hydrogen production from hydrogen-containing compounds, but also further increases the conversion rate of hydrogen-containing compounds and avoids the drawback of catalysts being less prone to deactivation.

[0063] According to the present invention, it is understood that any hydrogen-containing compound that can be dehydrogenated to produce hydrogen can be used to produce hydrogen using the catalyst of the present invention. There are no special restrictions on the specific types of hydrogen-containing compounds. In some embodiments, the hydrogen-containing compounds include at least one of methanol, ethanol, methylcyclohexane, cyclohexane, perhydrodibenzyltoluene, perhydronitroethylcarbazole, perhydrobenzyltoluene, petroleum atmospheric pressure cut fraction at 60-180°C, products of hydrogenation of petroleum 160-240°C fraction, gasoline, and diesel.

[0064] According to some preferred embodiments of the present invention, the hydrogen-containing compound includes one or more of methanol, ethanol, methylcyclohexane, and cyclohexane.

[0065] A fourth aspect of the present invention provides a method for producing hydrogen from hydrogen compounds, the method comprising: pre-treating the catalyst for producing hydrogen from hydrogen-containing compounds as described in claim 1 by reduction to obtain a reduced catalyst; and subjecting the hydrogen-containing compound to a dehydrogenation reaction in the presence of the reduced catalyst.

[0066] According to the present invention, the dehydrogenation reaction can be carried out in any dehydrogenation reactor in the art, and optionally, the dehydrogenation reaction is carried out in a highly integrated device.

[0067] According to the present invention, in some embodiments, the conditions for the reduction pretreatment are: temperature 300-450°C, atmospheric pressure; and / or hydrogen: catalyst volume 500-1000:1.

[0068] According to the present invention, in some embodiments of the method for producing hydrogen from hydrogen compounds, the hydrogen-containing compound includes methylcyclohexane and / or cyclohexane.

[0069] According to the present invention, the dehydrogenation conditions of the hydrogen-containing compound are not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the dehydrogenation conditions of the hydrogen-containing compound include a reaction temperature of 280-320°C.

[0070] According to the present invention, in some embodiments, the dehydrogenation conditions of the hydrogen-containing compound include: a mass hourly space velocity (HSV) of 2-5 h⁻¹ for the hydrogen-containing compound. -1 .

[0071] The present invention will be described in detail below through embodiments. In the following embodiments and comparative examples,

[0072] Methods for producing hydrogen from hydrogen-containing compounds:

[0073] The catalyst reduction pretreatment conditions are as follows: Before the reaction, the catalyst undergoes reduction pretreatment under the following conditions: temperature 300-450℃, atmospheric pressure, hydrogen:catalyst volume 800:1.

[0074] In the same highly integrated apparatus, the pretreated catalysts from the examples and comparative examples were contacted with cyclohexane; the contact temperature was 280°C and the mass hourly space velocity of methylcyclohexane was 2 h⁻¹. -1 .

[0075] Conversion rate % = (Amount of feed material at reactor inlet per unit time - Amount of feed material at reactor outlet per unit time) / Amount of feed material at reactor inlet per unit time * 100;

[0076] Selectivity = Amount of raw material producing the desired product / Amount of raw material fed * 100

[0077] Dehydrogenation rate = Amount of hydrogen produced by the reaction ÷ Reaction time ÷ Mass of noble metal elements on the catalyst surface;

[0078] The mass of noble metal elements on the catalyst surface was determined by carbon monoxide chemical adsorption at 25°C using a chemical adsorption-desorption apparatus after reduction.

[0079] Example 1

[0080] Preparation of catalysts for hydrogen production from hydrogen-containing compounds

[0081] Dissolve 0.06g chloroplatinic acid, 0.16g ferric nitrate nonahydrate, and 0.18g cobalt nitrate hexahydrate in 10g water to obtain the first solution; dissolve 0.84g C14 alkyltrimethylammonium bromide, 0.1g 37wt% hydrochloric acid aqueous solution, and 2.48g dichloroisohydrouric acid in 10g water at 80℃ to obtain the second solution.

[0082] The first solution was sprayed onto 10g of toothed spherical γ-Al2O3 (specific surface area of ​​210m²) using a spraying method. 2 / g, crushing strength of 100N / cm, 80% of the particles are 5-8nm in size, and the pore volume is 0.5cm³. 3On a surface with a diameter of 3 mm (g), the following conditions were met during spraying: the spraying temperature was 40℃, the spraying pressure was 0.03 kPaG, and the main rotation speed of the spraying machine was 5 r / min; then drying was carried out at a temperature of 120℃ for 12 h to obtain the sprayed γ-Al2O3.

[0083] The second solution was applied to the sprayed γ-Al2O3 at a temperature of 60°C, then dried at 120°C for 4 hours, and then calcined at 500°C for 6 hours to obtain a catalyst for hydrogen production from hydrogen-containing compounds.

[0084] ICP testing revealed that the catalyst contained 0.15 wt% Cl and 0.05 wt% bromine.

[0085] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0086] Example 2

[0087] Preparation of catalysts for hydrogen production from hydrogen-containing compounds

[0088] Dissolve 0.08g of chloroplatinic acid, 0.14g of ferric nitrate nonahydrate, and 0.2g of copper nitrate hexahydrate in 10g of water to obtain the first solution; dissolve 0.64g of C14 alkyltrimethylammonium bromide, 0.5g of 37wt% hydrochloric acid aqueous solution, and 2.48g of dichloroisohydrouric acid in 10g of water at 80℃ to obtain the second solution.

[0089] The first solvent was sprayed onto 10g of toothed spherical γ-Al2O3 (specific surface area of ​​210m²) using a spraying method. 2 / g, crushing strength of 100N / cm, 80% of the particles are 5-8nm in size, and the pore volume is 0.5cm³. 3 When spraying γ-Al2O3 on a surface with a diameter of 3 mm and a diameter of 3 mm, the spraying temperature is 40℃, the spraying pressure is 0.06 kPaG, the main speed of the spraying machine is 5 r / min, and then it is dried at a temperature of 120℃ for 12 h to obtain the sprayed γ-Al2O3.

[0090] The second solution was applied to the sprayed γ-Al2O3 at a temperature of 60°C, then dried at 120°C for 4 hours, and then calcined at 500°C for 6 hours to obtain a catalyst for hydrogen production from hydrogen-containing compounds.

[0091] ICP testing revealed that the catalyst contained 0.16 wt% Cl and 0.04 wt% bromine.

[0092] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0093] Example 3

[0094] Preparation of catalysts for hydrogen production from hydrogen-containing compounds

[0095] Dissolve 0.1g of chloroplatinic acid, 0.15g of ferric nitrate nonahydrate, and 0.06g of ammonium molybdate in 10g of water to obtain the first solution; dissolve 0.6g of C16 alkyltrimethylammonium bromide, 0.6g of 37wt% hydrochloric acid aqueous solution, and 2.0g of dichloroisohydrouric acid in 10g of water at 80℃ to obtain the second solution.

[0096] 10g of toothed spherical γ-Al2O3 (specific surface area 210m²) was sprayed using a spraying method. 2 / g, crushing strength of 100N / cm, 80% of the particles are 5-8nm in size, and the pore volume is 0.5cm³. 3 When spraying γ-Al2O3 onto a surface with a diameter of 3 mm and a spraying temperature of 40℃, a spraying pressure of 0.06 kPaG, and a main unit speed of 5 r / min, the γ-Al2O3 is obtained after drying at a temperature of 120℃ for 12 hours.

[0097] The second solution was applied to the sprayed γ-Al2O3 at a temperature of 80°C, then dried at 120°C for 4 hours, and then calcined at 500°C for 6 hours to obtain a catalyst for hydrogen production from hydrogen-containing compounds.

[0098] ICP testing revealed that the catalyst contained 0.12 wt% Cl and 0.03 wt% bromine.

[0099] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0100] Example 4

[0101] The method of Example 3 is the same as in Example 3, except that 2g of C16 alkyltrimethylammonium bromide, 0.3g of 37wt% hydrochloric acid aqueous solution, and 1g of dichloroisohydrouric acid are dissolved in 10g of water at 80°C to obtain a second solution.

[0102] ICP testing revealed that the catalyst contained 0.06% Cl and 0.1% bromine.

[0103] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0104] Example 5

[0105] The method of Example 3 is the same as that in Example 3, except that 0.3g of C16 alkyltrimethylammonium bromide, 0.1g of 37wt% hydrochloric acid aqueous solution, and 2.48g of dichloroisohydrouric acid are dissolved in 10g of water at 80°C to obtain a second solution, and the rest is the same as in Example 3.

[0106] ICP testing revealed that the catalyst contained 0.15% Cl and 0.01% bromine.

[0107] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0108] Example 6

[0109] The method of Example 3 is the same as that in Example 3, except that the first solution (same as Example 1) and the second solution (same as Example 1) are mixed and sprayed onto 10g of toothed spherical γ-Al2O3 (same as Example 1) using a spraying method (spraying conditions are the same as in Example 3), and the rest is the same as in Example 3.

[0110] ICP testing revealed that the catalyst contained 0.12% Cl and 0.03% bromine.

[0111] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0112] Example 7

[0113] The method of Example 3 differs in that:

[0114] First, the second solution (same as in Example 3) was brushed onto γ-Al2O3 and dried, and then the first solution (same as in Example 1) was sprayed onto it. After that, drying and calcination were carried out. The brushing conditions, spraying conditions, drying and calcination were the same as in Example 3.

[0115] ICP testing revealed that the catalyst contained 0.11% Cl and 0.03% bromine.

[0116] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0117] Comparative Example 1

[0118] The method of Example 3 is the same as in Example 3, except that the γ-Al2O3 sprayed in Example 3 is directly calcined to obtain a catalyst for hydrogen production from hydrogen-containing compounds.

[0119] Without a second solution, the sprayed γ-Al2O3 was dried at 120°C for 4 hours and then calcined at 500°C for 6 hours to obtain a catalyst for hydrogen production from hydrogen-containing compounds.

[0120] The selectivity, conversion, and 72-hour conversion and dehydrogenation rate of methylcyclohexane are shown in Table 1.

[0121] Comparative Example 2

[0122] The method of Example 3 is the same, except that 3.4 g of C16 alkyltrimethylammonium bromide is dissolved in 10 g of water at 80 °C to obtain a second solution;

[0123] The rest is the same as in Example 3.

[0124] ICP testing revealed that the catalyst contained 0 wt% Cl and 0.15 wt% bromine.

[0125] The selectivity and conversion of toluene at 1 h, and the conversion and dehydrogenation rate at 72 h are shown in Table 1.

[0126] Comparative Example 3

[0127] The method of Example 3 differs in that:

[0128] 2.75g of dichloroisocyanuric acid was mixed with 10g of water at 80°C to obtain a second mixture; the second mixture was then applied to the sprayed γ-Al2O3 (same as in Example 1); the rest was the same as in Example 1.

[0129] ICP testing revealed that the catalyst contained 0.15 wt% Cl and 0 wt% bromine.

[0130] The selectivity and conversion of toluene at 1 h, and the conversion and dehydrogenation rate at 72 h are shown in Table 1.

[0131] Table 1

[0132]

[0133] As can be seen from the results in Table 1, Examples 1-7, which use the simultaneous addition of bromine and chlorine according to the present invention, have higher stability and activity, and significantly better effects.

[0134] 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. The application of a catalyst for hydrogen production from hydrogen-containing compounds, characterized in that, The catalyst includes a support and a dehydrogenation active component and a halogen supported on the support; The dehydrogenation active components include noble metal oxides and variable-valence metal oxides; Based on the total mass of the carrier, the content of the dehydrogenation active component is 0.3-2.5 wt%; Based on the total mass of the carrier, the halogen content, calculated by element, shall not exceed 0.2 wt%. The halogens include bromine and chlorine; The noble metal oxide is selected from one or more of platinum oxide, palladium oxide, ruthenium oxide, rhodium oxide, and iridium oxide; The variable-valence metal oxide includes at least two of molybdenum oxide, iron oxide, copper oxide, cobalt oxide, vanadium oxide, chromium oxide, manganese oxide, and tungsten oxide.

2. The application according to claim 1, wherein, Based on the total mass of the carrier, the halogen content, calculated as an element, is 0.01-0.2 wt%. The mass ratio of bromine to chlorine is 1:(1-10) based on elemental composition. And / or, Based on the total mass of the carrier, the content of the dehydrogenation active component is 0.7-2.3 wt%.

3. The application according to claim 2, wherein, Based on the total mass of the carrier, the halogen content, calculated as elemental, is 0.1-0.2 wt%. The mass ratio of bromine to chlorine is 1:(2-6) based on elemental composition.

4. The application according to claim 1, wherein, Based on the total mass of the carrier, the content of the noble metal oxide is greater than 0.1 wt%; and / or The content of the variable valence metal oxide is not less than 0.01 wt%; The noble metal oxide is one or more of platinum oxide, palladium oxide, and rhodium oxide; and / or The variable-valence metal oxide includes at least two of molybdenum oxide, iron oxide, copper oxide, and cobalt oxide.

5. The application according to claim 4, wherein, Based on the total mass of the carrier, the content of the noble metal oxide is 0.2-0.8 wt%; and / or The content of the variable valence metal oxide is 0.01-2 wt%; The variable-valence metal oxide includes iron oxide, and a combination of at least one of molybdenum oxide, copper oxide, and cobalt oxide.

6. The application according to claim 5, wherein, The content of the variable valence metal oxide is 0.5-1.5 wt%; The variable valence metal oxide contains 20-60 wt% iron oxide.

7. The application according to claim 1, wherein, The support is selected from one or more of γ-Al2O3, silicon dioxide, magnesium aluminum spinel, and MCM-41; The carrier is spherical and / or toothed; and / or The diameter of the carrier is 2-6 mm; and / or The carrier has a pore volume greater than 0.2 cm³. 3 / g; and / or The proportion of pores of 5-8 nm in the carrier is greater than 80%; and / or The specific surface area of ​​the carrier is greater than 180m². 2 / g; and / or The crushing strength of the carrier is not less than 100 N / cm.

8. The application according to claim 7, wherein, The support is γ-Al2O3; The pore volume of the carrier is 0.5-0.8 cm. 3 / g; and / or The carrier has a pore size of 5-8 nm with a pore size ratio of 85-95%; and / or The specific surface area of ​​the carrier is 210-280 m². 2 / g; and / or The crushing strength of the carrier is 100-200 N / cm.

9. The application according to any one of claims 1-8, wherein, The preparation method of the catalyst for hydrogen production from hydrogen-containing compounds includes: a support being first contacted with a first solution containing a dehydrogenation active component source, optionally undergoing a first drying, followed by a second contact with a second solution containing a halogen source, and then sequentially undergoing a second drying and calcination.

10. The application according to claim 9, wherein, The halogen source includes quaternary ammonium salts that provide halogens and / or halogen compounds containing at least one halogen and hydrogen.

11. The application according to claim 10, wherein, The halogen source includes a quaternary ammonium salt that provides halogens and a halogen compound containing at least one halogen and hydrogen.

12. The application according to claim 11, wherein, The weight ratio of the quaternary ammonium salt providing the halogen to the halogen compound containing at least one halogen and hydrogen is 1:(1-10).

13. The application according to claim 12, wherein, The weight ratio of the quaternary ammonium salt providing the halogen to the halogen compound containing at least one halogen and hydrogen is 1:(1.5-5).

14. The application according to claim 10, wherein, The quaternary ammonium salt includes C12-C20 alkyltrimethylammonium halide and / or C12-C20 alkyldimethylbenzylammonium halide; And / or, The halogen compound is selected from one or more of perchloric acid, hypochlorous acid, hydrochloric acid, hydrogen bromide, hydrogen iodide, dichloroisohydrouric acid, trichloroisohydrouric acid, chloroacetic acid, and acyl chloride.

15. The application according to claim 14, wherein, The quaternary ammonium salt includes C14-C16 alkyltrimethylammonium halide and / or C14-C16 alkyldimethylbenzylammonium halide; And / or, The halogen compound is selected from hydrochloric acid and / or dichloroisohydrouric acid.

16. The application according to claim 11, wherein, The halogen source includes C14-C16 alkyltrimethylammonium bromide and / or C14-C16 alkyldimethylbenzylammonium bromide, as well as hydrochloric acid and / or dichloroisohydrouric acid.

17. The application according to claim 9, wherein, The methods of first and second contact are each selected from one of the following: wet soaking, spraying, spraying, or brushing.

18. The application according to claim 17, wherein, The first contact method is spraying; and / or The second contact method is the brushing method.

19. The application according to claim 18, wherein, The conditions for the brushing method include: The application temperature is 40-80℃; and / or The conditions for spray coating include: The spraying temperature is 40-80℃; and / or The spraying pressure is 0.01-0.08 kPaG; and / or The main unit of the spraying machine rotates at 5-10 r / min during spraying.

20. The application according to claim 1, wherein, The catalyst is used at a temperature of 280-320℃. The hydrogen-containing compounds include one or more of the following: methanol, ethanol, methylcyclohexane, cyclohexane, perhydrodibenzyltoluene, perhydronitroethylcarbazole, perhydrobenzyltoluene, petroleum atmospheric pressure fractions at 60-180°C, products of hydrogenation of petroleum fractions at 160-240°C, gasoline, and diesel.

21. The application according to claim 20, wherein, The hydrogen-containing compound includes one or more of methanol, ethanol, methylcyclohexane, and cyclohexane.

22. A method for producing hydrogen from hydrogen-containing compounds, characterized in that, The method includes: pre-treating the catalyst for hydrogen production from hydrogen-containing compounds according to any one of claims 1-21 by reduction to obtain a reduced catalyst; and subjecting the hydrogen-containing compounds to a dehydrogenation reaction in the presence of the reduced catalyst. Optionally, the dehydrogenation reaction is carried out in a highly integrated device.

23. The method of claim 22, wherein, The conditions for reduction pretreatment are: temperature 300-450℃, atmospheric pressure; and / or Hydrogen: Catalyst volume ratio 500-1000:1; The hydrogen-containing compound includes methylcyclohexane and / or cyclohexane; and / or The dehydrogenation conditions for the hydrogen-containing compound include: The reaction temperature is 280-320℃; and / or The mass hourly space velocity (MSV) of hydrogen-containing compounds is 2-5 h⁻¹. -1 .

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