In oxide substance and method for producing alkene or aromatic compound

Abstract

This In oxide substance contains In and O and is used in a dehydrogenation reaction in which an alkane is dehydrogenated to produce an alkene and / or an aromatic compound.

Description

Indium oxide-based substance and method for producing alkene or aromatic compound

[0001] This specification discloses an In-oxide based material and a method for producing an alkene or aromatic compound.

[0002] For example, ethane, an alkane, is a relatively abundant resource found in natural gas. With the shale gas revolution making it possible to extract natural gas from shale layers, the amount of ethane extracted is expected to increase further in the future.

[0003] In industry, much of the ethane is synthesized into ethylene, which is used as a raw material for synthetic resins and various other compounds.

[0004] On the other hand, alkanes, including ethane, are stable hydrocarbons. Therefore, the currently widely adopted method of synthesizing ethylene from ethane by thermal decomposition in the presence of steam requires a high-temperature reaction, which consumes a large amount of energy.

[0005] In contrast, it is expected that alkenes and the like can be synthesized with less energy by a dehydrogenation reaction of alkanes using a catalyst of an inorganic compound such as a predetermined metal oxide. Examples of this type of technology include those described in Patent Documents 1 to 3.

[0006] Patent Document 1 describes "a method for preparing olefins from C2-, C3-, or C4-alkanes, or a mixture thereof, comprising the following steps: a) heating the C2-, C3-, or C4-alkanes, or a mixture thereof; b) passing the heated C2-, C3-, or C4-alkanes, or a mixture thereof, over a catalyst, the catalyst comprising i) at least one metal compound selected from the group consisting of metal carbides, nitrides, silicides, phosphides, and sulfides of a metal selected from the group consisting of molybdenum, tungsten, tantalum, vanadium, titanium, niobium, lanthanum, and chromium, and mixtures thereof, and ii) at least one non-Brønsted acid type binder selected from the group consisting of AlPO4, bentonite, AlN, and N4Si3, thereby producing a product mixture comprising at least one olefin, methane, and hydrogen; and c) separating the product mixture."

[0007] Patent Document 2 describes a process for converting ethane into ethylene and acetic acid in the gas phase at a temperature of 450° C. or less in the presence of oxygen, wherein the catalyst is a catalyst selected from the group consisting of MoV a Nb b Te c Z d O n wherein Z is at least one element selected from the group consisting of W, Cr, Ta, Ti, Zr, Hf, Mn, Re, Fe, Ru, Co, Rh, Ni, Pd, Pt, Ag, Au, Zn, B, Al, Ga, In, Ge, Sn, Pb, P, Bi, Y, rare earth elements, and alkaline earth elements, a = 0.01 to less than 1.0, b = 0.01 to less than 1.0, c = 0.01 to less than 1.0, d = 0.0 to less than 1.0, and n is determined by the oxidation states of the other elements.

[0008] Patent Document 3 describes "a process for converting paraffins to olefins, the process comprising the following steps: (a) providing a hydrocarbon feedstock containing at least one paraffin having from 1 to 12 carbon atoms and at least one olefin having from 2 to 12 carbon atoms; (b) providing a catalyst containing at least one Group VIA and / or Group VIIA transition metal on a solid support; (c) pretreating the catalyst by contacting the catalyst with at least one reducing gas and at least one oxidizing gas; and (d) contacting the hydrocarbon feedstock with the pretreated catalyst at a temperature within the range of from 200° C. to 600° C., preferably from 320° C. to 450° C.," wherein "the at least one Group VIA or Group VIIA transition metal is molybdenum, tungsten, rhenium, or a mixture thereof, preferably tungsten."

[0009] JP 2015-516867 A JP 2015-516952 A JP 2018-69231 A

[0010] Although Patent Documents 1 to 3 focus on inorganic compounds such as Mo, V, Te, and Nb as catalysts for use in dehydrogenation reactions, there is a possibility that other inorganic compounds may exist that are effective in dehydrogenating alkanes. However, inorganic compounds such as Mo, V, Te, and Nb require the use of oxygen from the atmosphere for the reaction, which does not necessarily mean that a safe reaction can be achieved.

[0011] This specification provides an In oxide-based material that can be effectively used in the dehydrogenation of alkanes, and a method for producing alkenes or aromatic compounds.

[0012] The In oxide-based material disclosed in this specification contains In and O and is used in dehydrogenation reactions in which alkanes are dehydrogenated to produce alkenes and / or aromatic compounds.

[0013] The method for producing an alkene or an aromatic compound disclosed in this specification is a method for producing an alkene and / or an aromatic compound from an alkane, and uses the above-mentioned In oxide-based substance.

[0014] The above-mentioned In oxide-based substances can be effectively used in the dehydrogenation reaction of alkanes.

[0015] FIG. 2 is a schematic diagram of a reaction assumed in a dehydrogenation reaction using an In oxide-based material of one embodiment. FIG. 3 is a schematic diagram showing an example of composition changes of an In oxide-based material due to the reaction of FIG. 1. FIG. 4 is an X-ray diffraction profile of the material of Example 1. FIG. 5 is a schematic diagram showing an outline of activity tests of the examples. FIG. 6 is a graph showing TG test results of the material of Example 1. FIG. 7 is a graph showing TG test results of the material of Example 9. FIG. 8 is a graph showing TG test results of the material of Example 11. FIG. 9 is a graph showing TG test results of the material of Example 14. FIG. 10 is a graph showing TG test results of the material of Example 17. FIG. 11 is a graph showing TG test results of the material of Example 18.

[0016] Hereinafter, embodiments of the above-mentioned In oxide-based substance and method for producing an alkene or an aromatic compound will be described in detail.

[0017] (In Oxide-Based Substance) The In oxide-based substance contains at least In (indium) and O (oxygen), and includes In oxides which are compounds of In and O. In this embodiment, the In oxide-based substance is used in the dehydrogenation reaction of an alkane.

[0018] Dehydrogenation reactions involve the dehydrogenation of alkanes to produce alkenes and / or aromatic compounds. In such dehydrogenation reactions, as will be described in detail below, In oxide-based materials dehydrogenate alkanes through reduction and oxidation reactions due to the loss and replenishment of interstitial oxygen, generating HO. While they contribute to the reaction as a so-called oxygen carrier, they also function as a catalyst, changing the reaction rate as a whole. While simple dehydrogenation may occur in some areas, oxidative dehydrogenation (ODH), particularly chemical looping oxidative dehydrogenation (CL-ODH), may predominate. This allows for lower reaction temperatures compared to the thermal decomposition of alkanes to produce alkenes, resulting in reduced energy consumption.

[0019] The In oxide-based substance may contain In2O3. In this case, the In content of the In oxide-based substance is preferably 7 at% to 40 at%. If the In content is too low or too high, the performance, such as selectivity, conversion rate, and ethylene production amount, when used in a reaction may be insufficient compared to when the In content is within the optimal range. For this reason, the In content of the In oxide-based substance is preferably 20 at% to 40 at%.

[0020] The In content of the In oxide-based material can be measured using an ICP optical emission spectrometer. Specifically, for metal elements such as In, powder is dissolved in acid or the like and analyzed using an ICP optical emission spectrometer (SPS3100HV manufactured by Hitachi High-Tech Science Corporation) or a device substantially equivalent thereto. The amount of In can then be measured to calculate the amount of In2O3. The same applies to Cu and Ni, and the Cu content, Ni content, and Co content described below can also be measured using the same method. To calculate the specific content, a calibration curve is used for each measured element. The standard solution for chemical analysis (Ni, In, Cu 1000 mg / L) from Kanto Chemical Co., Inc. can be used as the standard solution.

[0021] The In oxide-based substance may contain only In oxide such as In2O3, but may also contain compounds such as metals, alloys, or oxides other than In. For example, the In oxide-based substance may contain at least one element selected from the group consisting of Cu, Ni, and Co, regardless of the form of a metal, alloy, compound, or the like. It is preferable that the In oxide-based substance contain both Cu and Ni. In this case, high ethane conversion and ethylene selectivity may be obtained, as will be described in the Examples section below.

[0022] Typically, the In oxide-based substance may contain a metal oxide other than In oxide (hereinafter, simply referred to as "metal oxide"). Specifically, the In oxide-based substance may contain, in addition to In oxide, a metal oxide containing at least one metal selected from the group consisting of Cu (copper), Ni (nickel), and Co (cobalt) (i.e., a Cu-containing oxide, a Ni-containing oxide, and / or a Co-containing oxide). When the In oxide-based substance contains a Cu-containing oxide or a Ni-containing oxide, CL-ODH proceeds more easily when used in a reaction, and it is possible to increase the selectivity and conversion rate by adjusting the amount of Cu or Ni added. When the In oxide-based substance contains a Co-containing oxide, a simple dehydrogenation reaction may be more prevalent than ODH. When an In oxide-based substance containing such a metal oxide is used one or more times in a dehydrogenation reaction such as that described below, at least a portion of the metal element in the metal oxide is often converted into a form such as a metal and / or an alloy with In or the like.

[0023] When the In oxide-based substance contains an oxide containing Cu, the Cu content of the In oxide-based substance is preferably 1.5 at% to 30 at%, more preferably 20 at% to 25 at%. If the Cu content is too low or too high, the performance, such as selectivity, conversion rate, and amount of ethylene produced, when used in a reaction may be insufficient compared to when the Cu content is within the optimum range.

[0024] Examples of oxides containing Cu include Cu oxides such as CuO and CuO, and composite oxides containing Cu and In such as CuInO. In particular, In oxide-based substances may contain CuO and / or CuInO. When an In oxide-based substance contains CuO or CuInO, the oxidative dehydrogenation reaction of alkanes occurs at a lower temperature than an In oxide-based substance containing only In oxide, and an alloy of In and Cu is formed, which tends to result in a chemical looping type oxidative dehydrogenation reaction.

[0025] Furthermore, the In oxide-based substance may contain NiO as an oxide containing Ni, and in this case, the Ni content is preferably 1.5 at% to 30 at%. If the Ni content of the In oxide-based substance containing NiO is too low or too high, the performance when used in a reaction, such as selectivity, conversion rate, and amount of ethylene produced, may be insufficient compared to when the Ni content is in the optimal range. It is even more preferable that the Ni content of the In oxide-based substance be 2 at% to 25 at%.

[0026] Furthermore, the In oxide-based substance may contain CoO and / or Co3O4 as a Co-containing oxide. In this case, the Co content of the In oxide-based substance is preferably 1.5 at% to 30 at%, more preferably 20 at% to 25 at%. If the Co content is too low or too high, the performance, such as selectivity, conversion rate, and ethylene production amount, when used in a reaction may be insufficient compared to when the Co content is within the optimal range.

[0027] The presence of the above-described oxides in the In oxide-based substance can be confirmed by X-ray diffraction (XRD). Specifically, in accordance with JIS K0131:1996, measurements are performed using an Ultima IV powder X-ray diffractometer manufactured by Rigaku Corporation or an equivalent device under the following conditions: X-ray source: Cu-Kα, tube voltage: 40 kV, tube current: 30 mA, divergence slit: 1°, divergence vertical limiting slit: 10 mm, scattering slit: 8 mm, receiving slit: open, goniometer: sample horizontal type, scan speed: 20° / min, scan step: 0.02°, measurement range: 2θ = 20° to 120°.

[0028] Furthermore, by checking the magnitude of the peak intensity representing each oxide in the X-ray diffraction profile obtained by the above-mentioned X-ray diffraction method, it is possible to estimate the amount of metal oxides other than In oxide contained in the In oxide-based substance. When an In oxide-based substance containing In2O3 and a metal oxide other than In oxide is analyzed by X-ray diffraction, the resulting X-ray diffraction profile may show, for example, a peak intensity of the strongest line (222) of In2O3 that is 0.05 times or more the peak intensity of the strongest line of the metal oxide. Typically, the peak intensity of the strongest line (222) of In2O3 may be 0.08 to 25 times the peak intensity of the strongest line of the metal oxide. Note that when multiple metal oxides are contained, the ratio of the peak intensity of the strongest line (222) of In2O3 to the peak intensity of the strongest line of at least one of the metal oxides among them may be equal to or greater than the above-mentioned lower limit or within the above-mentioned range. When the above peak intensity ratio is determined from the X-ray diffraction profile, automatic background processing and fitting processing are performed using the integrated powder X-ray analysis software PDXL2 manufactured by Rigaku Corporation, which is analysis software attached to the powder X-ray diffractometer.

[0029] In an In oxide-based substance containing In2O3 and CuO, the peak intensity of the strongest line (222) of In2O3 in the X-ray diffraction profile may be 0.1 to 10 times that of the strongest line of CuO. In an In oxide-based substance containing In2O3 and Cu2In2O5, the peak intensity of the strongest line (222) of In2O3 in the X-ray diffraction profile may be 0.1 to 10 times that of the strongest line of Cu2In2O5. In an In oxide-based substance containing In2O3 and NiO, the peak intensity of the strongest line (222) of In2O3 in the X-ray diffraction profile may be 0.5 to 25 times that of the strongest line of NiO. However, when NiO or In2O3 is highly dispersed on Cu2In2O5 by changing or adjusting the synthesis method, increasing the compounding ratio of Cu / In or Ni / In, or other conditions, the peak intensity in the X-ray diffraction method decreases, the peak intensity of the strongest line (222) of In2O3 becomes almost zero, and the peak intensity ratio may fall outside the above range.

[0030] Although not limited to this, it is desirable that the In oxide-based substance be in a powder form from the viewpoint of increasing the specific surface area and enhancing reactivity. The powdered In oxide-based substance has a specific surface area of ​​0.5 m 2 / g to 100m 2 The specific surface area can have a value of 1 / g. This specific surface area is measured using a Macsorb (manufactured by Mountec Co., Ltd.).

[0031] The above-mentioned In oxide-based material can be produced by, for example, the solid-state reaction method or complex polymerization method described below, but is not limited to these production methods.

[0032] In the solid-state reaction method, a raw material powder is prepared as follows: a single powder of In oxide powder such as In2O3 powder, or a mixed powder of In oxide powder and at least one metal oxide powder selected from the group consisting of Cu oxide powder, Ni oxide powder, and Co oxide powder. The raw material powder is prepared by blending appropriate amounts of In oxide powder and metal oxide powder depending on the target composition of the In oxide-based material. The raw material powder may have an average particle size of 0.1 μm to 10 μm, for example.

[0033] The raw material powder can then be fired, for example, in an air atmosphere at a temperature of 600°C to 900°C, typically 600°C to 850°C, for 1 to 10 hours. The upper limit of the firing time is preferably 10 hours in order to shorten the time required for production, but since the physical properties are not expected to change even if the firing is performed for a long period of time, a firing time longer than 10 hours is acceptable. At this time, if the raw material powder contains an In oxide powder and a Cu oxide powder, at least a portion of the powder may become a composite oxide such as CuInO. After firing, an In oxide-based material is obtained.

[0034] In one example of the complex polymerization method, metal nitrates, including In nitrate and, if necessary, Cu nitrate, Ni nitrate, and / or Co nitrate, are dissolved in a liquid such as pure water to form a solution, to which citric acid and ethylene glycol are added. The solution is then stirred and evaporated to dryness, and the resulting solid is heated and calcined.

[0035] In this firing, pre-firing may be performed first, followed by main firing. The pre-firing may be performed in an air atmosphere at 300°C to 500°C (400°C in one example) for 1 to 3 hours (2 hours in one example), and the main firing may be performed in an air atmosphere at 700°C to 1100°C (for example, 700°C, 850°C, or 1100°C) for 1 to 10 hours (10 hours in one example). After firing, an In oxide-based substance is obtained.

[0036] (Method for Producing Alkenes or Aromatic Compounds) To produce alkenes and / or aromatic compounds from alkanes using the In oxide-based substance described above, the In oxide-based substance can be placed, for example, in a flow-type reactor such as a fixed bed, fluidized bed, or moving bed, by packing the In oxide-based substance.

[0037] Then, while the reactor in which the In oxide-based material is placed is heated, a gas containing an alkane such as ethane is supplied into the reactor.

[0038] The feed gas to the reactor may be any gas containing an alkane. Supplying this gas to the In oxide-based material in the reactor causes a dehydrogenation reaction, followed by an oxidation reaction (a reduction reaction for the In oxide-based material) to produce alkenes and / or aromatic compounds. The feed gas may contain at least one alkane, such as methane, ethane, propane, or butane, or may contain multiple alkanes. Next, the gas species is switched, and an oxygen-containing gas, such as CO or HO, is again supplied to the In oxide-based material in the reactor. This oxidation reaction occurs in which the oxygen in the feed gas replenishes the oxygen lost in the In oxide-based material due to the reduction reaction during the alkane dehydrogenation reaction. This feed gas may be diluted with an inert gas, such as nitrogen, argon, or helium. By alternately supplying different feed gases into the reactor in this way, reduction and oxidation reactions can be repeatedly performed (see Figure 1).

[0039] The reaction temperature in the reactor can be, for example, 300°C to 800°C, preferably 450°C to 650°C. Furthermore, W / F, which is the weight (g) of the In oxide-based substance divided by the flow rate (mL / sec) of the reactant gas, can be, for example, 0.1 g·sec / mL to 0.9 g·sec / mL, typically 0.3 g·sec / mL to 0.7 g·sec / mL. W / F represents the time during which 1 mL of the reactant gas is in contact with 1 g of material.

[0040] When reacted in a reactor under the above conditions, the interstitial oxygen in the In oxide-based material combines with hydrogen in the alkane to produce water (ODH). Next, by switching the gas species to CO or HO, the oxygen missing in the In oxide-based material is replenished with oxygen contained in the supply gas. These reduction and oxidation reactions occur repeatedly, yielding the desired product, such as an alkene (CL-ODH). While the possibility of a simple dehydrogenation reaction occurring upon introduction of the reducing gas cannot be ruled out, the presence of the In oxide-based material is expected to favor chemical looping oxidative dehydrogenation. In the case of In oxide-based materials containing In oxide and metal oxide, it is speculated that in such dehydrogenation reactions, In alloys with the metal when oxygen deficiency occurs due to the reduction reaction, as shown in Figure 2.

[0041] In the dehydrogenation reaction, hydrogen is lost from alkanes such as ethane to produce alkenes such as ethylene, and further condensation cyclization produces aromatic compounds such as benzene. As a result, alkenes and / or aromatic compounds can be produced from alkanes in a reaction at a relatively low temperature.

[0042] The above-mentioned In oxide-based material was experimentally produced and its effects confirmed, which will be described below. However, the description here is for illustrative purposes only and is not intended to be limiting.

[0043] (In oxide-based materials and other materials) In oxide-based materials (Examples 1 to 27) and materials made of other materials (Comparative Examples 1 to 3) having the compositions shown in Table 1 were each produced by the solid-state reaction method or complex polymerization method described above. In the solid-state reaction method, the temperature was 850°C and the time was 10 hours. In the complex polymerization method, the main firing temperature was 850°C and the time was 10 hours. The physical mixing method is essentially the same as the solid-state reaction method except that firing is not performed, and is carried out by mixing multiple predetermined types of raw material powders in a mortar.

[0044] In Table 1, "In (at %)," "O (at %)," "Cu (at %)," and "Ni (at %)" in the "Calculated Values" column are the respective contents of In, O, Cu, and Ni in the substance calculated from the contents of In, O, Cu, and Ni in the raw material powder. Furthermore, for the In oxide-based substances of Examples 22 to 27, the respective contents of In, Cu, and Ni were measured using an ICP optical emission spectrometer according to the method described above. The results are also shown in Table 1. In the "ICP Analysis Results" column in Table 1, "Remaining O (at %)" is the value obtained by subtracting the total content of In, Cu, and Ni from 100 at %.

[0045] From Table 1, it can be seen that the "calculated value" and the "ICP analysis result" contents are almost the same in Examples 22 to 27. From this, although ICP emission spectroscopy was not performed in Examples 1 to 21, it is expected that the ICP analysis results will be substantially the same as the "calculated value."

[0046] The substances of Examples 1 to 27 and Comparative Examples 1 to 3 were analyzed by the X-ray diffraction method described above, and as a result, it was confirmed that each oxide with the composition shown in Table 1 was contained. For reference, the X-ray diffraction profile of Example 1 is shown in FIG. 3. In addition, the peak intensity ratio of the peak intensity of the strongest line (222) of In2O3 determined from the X-ray diffraction profile by the method described above to the peak intensity of the strongest line of the metal oxide is shown in Table 1. For the peak intensity ratios in Table 1, the numerator is In2O3(222), and the denominator is the peak intensity of the oxide shown in Table 1. Note that 2θ = 43.3 for NiO(012), and 2θ = 30.6 for In2O3(222).

[0047]

[0048] (Activity Test) Activity tests were conducted using a fixed-bed flow reactor for each of the substances in Examples 1 to 24 and Comparative Examples 1 to 3. More specifically, as shown in FIG. 4, 0.5 g of substance was loaded into a reactor, and gas with an ethane partial pressure of 0.5 atm was supplied at a total flow rate of 60 mL / min at a predetermined reaction temperature. The ethane supply rate was 150 mL per 5 minutes. H2O produced during the reaction was captured using a cold trap. The reaction was carried out for 10 minutes, and the gas that flowed out of the reactor during the reaction was collected. Next, gas with a CO2 partial pressure of 0.5 atm was supplied at a total flow rate of 60 mL / min. The reaction was carried out for 60 minutes, and the gas that flowed out of the reactor during the reaction was collected. The introduction of these ethane gas and CO2 gases constituted one cycle, and a total of three test cycles were conducted. Argon was used to dilute the ethane-containing gas and CO2-containing gas.

[0049] The components of the gas collected during the reaction were analyzed using a gas chromatograph (GC-2014) manufactured by Shimadzu Corporation, and it was found that the gas may contain, in addition to ethylene, carbon monoxide, methane, carbon dioxide, ethane, hydrogen, etc. Then, from the analytical data obtained by the gas chromatograph, the ethane conversion, ethylene selectivity, and ethylene production amount were determined. Here, the ethane conversion and ethylene selectivity were calculated using the following formulas, respectively. The results are shown in Table 2. The ethane conversion, ethylene selectivity, and ethylene production amount shown in Table 2 are values ​​for the first five minutes of the second cycle out of three cycles, except for Comparative Example 1, and in Comparative Example 1, they are values ​​for the first five minutes of the first cycle. Ethane conversion (%) = (number of moles of consumed ethane / number of moles of fed ethane) × 100 Ethylene selectivity (%) = (number of moles of produced ethylene / number of moles of consumed ethane) × 100

[0050]

[0051] As can be seen from Table 2, in all of Examples 1 to 24, more ethylene was produced than in Comparative Examples 1 to 3. In particular, the In oxide-based materials of Examples 10 to 18, which contained Ni and Cu in addition to In2O3, had higher ethane conversion than the In oxide-based materials of Examples 7 and 8, which contained only In2O3. Furthermore, when the In oxide-based material of Example 9, which contained Cu but no Ni, was compared with the In oxide-based material of Example 18, which contained a trace amount of Ni in addition to Cu, the In oxide-based material of Example 18 had a higher ethylene selectivity. Although the ethylene selectivity of Comparative Example 1 was high, the amount of ethane consumed was small, resulting in only a small amount of ethylene being produced. Comparative Example 1 also produced a low amount of ethylene, similar to Comparative Examples 2 and 3.

[0052] (TG Test) A thermogravimetric analysis (TG) test was performed on each of the materials of Examples 1, 9, 11, 14, 17, and 18. In this test, a reduction step in which a reducing gas containing ethane was flowed and an oxidation step in which an oxidizing gas containing carbon dioxide was flowed were sequentially performed, and these steps constituted one cycle, and this cycle was repeated three times. This confirmed whether the interstitial oxygen of the material was used in the dehydrogenation reaction.

[0053] Specific test conditions included a weight of 30 mg of the substance to be tested and a reaction temperature of 600°C. The partial pressure of the reducing gas was 0.1 atm, the partial pressure of the carbon dioxide gas was 0.2 atm, and the total pressure of both the reducing gas and the oxidizing gas was 1.0 atm, with the remainder being argon, and the total flow rate was 100 mL / min. The reduction step lasted 30 minutes, and the oxidation step continued until reoxidation was complete.

[0054] As a result, Table 3 shows the amount of Redox, or the amount of oxygen released and absorbed, at each step of each cycle. In Table 3, "red" means the amount of oxygen released in a reducing atmosphere, and "oxi" means the amount of oxygen absorbed in an oxidizing atmosphere. These amounts of released and absorbed oxygen are values ​​calculated from the increase or decrease in weight under the assumption that all changes in weight are due to an increase or decrease in oxygen. The results for Examples 1, 9, 11, 14, 17, and 18 are shown in graphs in Figures 5 to 10, respectively.

[0055]

[0056] Table 3 and Figures 5 to 10 show that in Examples 1, 9, 11, 14, 17, and 18, the weight loss during the reduction step and the oxidation step was significant. This suggests that interstitial oxygen in the material was likely missing and replenished. This suggests that an oxidative dehydrogenation reaction may have occurred during this time, demonstrating chemical looping characteristics. Thermogravimetry (TG) showed that the weight loss upon heating to 650°C at a heating rate of 5°C / min in an ethane and argon mixed gas atmosphere was preferably 15 mmol / g or less.

[0057] From the above, it was suggested that the above-mentioned In oxide-based materials could be effectively used in the dehydrogenation reaction of alkanes.

Claims

1. In oxide-based substances containing In and O, It is used in dehydrogenation reactions in which alkenes and / or aromatic compounds are produced by the dehydrogenation of alkanes. In ２ O ３ It contains , and the In content is 7 at% to 40 at%. An in oxide-based material containing at least one element selected from the group consisting of Cu, Ni, and Co.

2. (delete)

3. (delete)

4. The In oxide-based material according to claim 1, comprising a metal oxide containing at least one metal selected from the group consisting of Cu, Ni, and Co.

5. The In oxide-based substance according to claim 4, wherein the metal oxide includes an oxide containing Cu, and the Cu content is 1.5 at% to 30 at%.

6. The In oxide-based material according to claim 5, wherein the Cu-containing oxide includes CuO.

7. The In oxide-based material according to claim 5, wherein the Cu-containing oxide includes a composite oxide containing Cu and In.

8. The composite oxide is Cu ２ In ２ O ５ An In oxide-based substance according to claim 7, comprising:

9. The In oxide-based material according to claim 4, wherein the metal oxide contains NiO, and the Ni content is 1.5 at% to 30 at%.

10. The metal oxide is CoO and / or Co ３ O ４ The In oxide-based substance according to claim 4, comprising and having a Co content of 1.5 at% to 30 at%.

11. For at least one metal oxide, in the X-ray diffraction profile obtained by the X-ray diffraction method, the peak intensity of the strongest line (222) of In ２ O ３ is 0.05 times or more the peak intensity of the strongest line of the metal oxide. The In oxide-based substance according to claim 4.

12. The aforementioned alkene and / or aromatic compound undergoes oxidation together with H ２ An In oxide-based substance according to claim 1 or 4, used in an oxidative dehydrogenation reaction that produces O.

13. The In oxide-based substance according to claim 12, wherein the oxidative dehydrogenation reaction includes a chemical looping oxidative dehydrogenation reaction.

14. The In oxide-based material according to claim 1 or 4, wherein, by thermogravimetric analysis (TG), the weight loss when heated to a temperature of 650°C at a heating rate of 5°C / min in a mixed gas atmosphere of ethane and argon is 15 mmol / g or less.

15. The In oxide-based substance according to claim 1 or 4, wherein the alkane contains ethane and the alkene contains ethylene.

16. A method for producing alkenes and / or aromatic compounds from alkanes, A method for producing an alkene or aromatic compound using the In oxide-based substance described in claim 1 or 4.