Catalyst for the decomposition of organic substances, honeycomb structure, process for the decomposition of organic substances and device for the decomposition of organic substances

Abstract

The present disclosure relates to a catalyst for the decomposition of organic substances and further relates to a structure coated with the catalyst for the decomposition of organic substances, a process for the decomposition of organic substances using the catalyst for the decomposition of organic substances, and an apparatus for the decomposition of organic substances comprising the catalyst for the decomposition of organic substances. The catalyst for the decomposition of organic substances according to the present disclosure serves for the oxidative decomposition of organic substances. The catalyst for the decomposition of organic substances contains a ternary mixed oxide of zirconium, manganese, and neodymium and decomposes organic substances oxidatively.The present disclosure can provide: a catalyst for the decomposition of organic substances which can exhibit high catalytic activity in the initial activity, can maintain high catalytic activity even after poisoning, and can be regenerated by heating even after poisoning; as well as a honeycomb structure, a process for the decomposition of organic substances, and an apparatus for the decomposition of organic substances which use the catalyst for the decomposition of organic substances.

Description

Technical field

[0001] The present invention relates to a catalyst for the decomposition of organic substances and further relates to a structure for the decomposition of organic substances, a method for the decomposition of organic substances and a device for the decomposition of organic substances. State of the art

[0002] The purification of exhaust gases consisting of organic hydrocarbons is usually achieved by mixing the exhaust gas with an oxygen-containing gas such as air and heating the resulting mixture so that the organic hydrocarbons are decomposed into water and carbon dioxide through an oxidation-combustion reaction. By using a catalyst material, exhaust gas purification can be carried out at lower temperatures and at higher rates; therefore, the use of a catalytic exhaust gas purification device can reduce the energy and costs involved in exhaust gas treatment. Common catalysts include active components such as platinum, palladium, manganese, and cobalt, which are mounted on ceramics such as aluminum oxide (alumina). Precious metals such as platinum and palladium enable exhaust gas treatment at lower temperatures than manganese- or cobalt-based catalysts, but they are expensive.

[0003] Patent document 1 proposes a BaZr(Mn)O3 catalyst (BZM catalyst) to improve the heat resistance of perovskite-type mixed oxide catalysts. Non-patent document 1 and non-patent document 2 propose Zr-Mn-based catalysts to suppress deterioration during the decomposition of chlorine-containing hydrocarbon gases. Patent document 2 proposes improving the properties of Zr-Mn-based catalysts by incorporating hydrothermal treatment and high-temperature steam treatment during the Zr-Mn-based catalyst manufacturing process. List of prior art patent documents Patent document 1: Japanese publication no. 2015-229137 Patent document 2: Chinese patent no. 111790374 Non-patent documents Nicht-Patentdokument 1: Jose I. Gutierrez-Ortiz et al., „Structure of Mn-Zr mixed oxides catalysts and their catalytic performance in the gas-phase oxidation of chlorocarbons,“ Chemosphere, 2007, Vol. 68, S. 1004-1012 Nicht-Patentdokument 2: D. Doebber et al., „MnOx / ZrO2 catalysts for the total oxidation of methane and chloromethane,“ Applied Catalysis B: Environmental, 2004, Vol. 52, S. 135-143 Kurzdarstellung der ErfindungTechnisches Problem

[0004] Common exhaust gas purification catalysts comprise platinum group precious metals such as platinum, rhodium, and palladium, supported on heat-resistant materials like aluminum oxide. In many catalysts where an active component is applied to a support such as aluminum oxide, fine particles of the active component are dispersed across the support to achieve high catalytic activity. As a result, the catalyst's activity tends to decrease slightly due to a reduction in the material surface area. Catalysts used for exhaust gas treatment are often exposed to high-temperature environments resulting from hot exhaust gas and the heat generated by the decomposition reaction. Furthermore, platinum, rhodium, and palladium are rare and expensive resources, and cost constraints can make it difficult to use large quantities of these metals in a large-scale catalytic exhaust gas purification system.

[0005] If a catalyst is not sufficiently heat-resistant or resistant to poisoning, its catalytic performance deteriorates rapidly, making the use of catalytic exhaust gas treatment more difficult and tending to increase energy costs for exhaust gas treatment. Therefore, there is a need for catalysts that can be used stably at higher temperatures, as well as for catalyst materials that are resistant to degradation by catalyst poisons such as sulfur (S), chlorine (Cl), and phosphorus (P).

[0006] The BZM catalyst disclosed in patent document 1 does exhibit improved heat resistance; however, it may show a deterioration in its catalytic properties when exposed to exhaust gas with high S or Cl concentrations, as these elements react with the catalyst components.

[0007] The Zr-Mn-based catalysts disclosed in Non-Patent Document 1, Non-Patent Document 2, and Patent Document 2 exhibit resistance to chlorinated hydrocarbons but insufficient heat resistance at elevated temperatures. If the exhaust gas treatment temperature reaches a high value, the catalyst particles can agglomerate, reducing the contact area between the catalyst and the gas and thereby impairing exhaust gas purification performance. Since the agglomeration of the catalyst particles leads to deformation of the catalyst itself, cracking can occur in pellet-shaped catalysts or flaking in catalyst-coated honeycomb structures, generating dust and raising concerns about adverse effects on exhaust gas treatment systems and downstream processes.

[0008] Therefore, catalysts must have a sufficiently high heat resistance, taking into account not only the operating temperature of the exhaust gas treatment system, but also the temperature increase due to the combustion of organic substances and the possibility of increasing the operating temperature to compensate for an insufficient treatment capacity.

[0009] The present invention relates to: a catalyst for the decomposition of organic substances which can exhibit high catalytic activity in its initial activity, which can maintain high catalytic activity even after poisoning and which can be regenerated by heating even after poisoning; as well as a honeycomb structure, a method for the decomposition of organic substances and a device for the decomposition of organic substances which use said catalyst for the decomposition of organic substances. Solution to the problem

[0010] The catalyst for the decomposition of organic substances according to the present invention is a catalyst for the oxidative decomposition of organic substances. The catalyst for the decomposition of organic substances contains a ternary mixed oxide of zirconium, manganese, and neodymium. Advantages of the invention

[0011] The present invention can provide: a catalyst for the decomposition of organic substances which can exhibit high catalytic activity in its initial activity, can maintain high catalytic activity even after poisoning, and can be regenerated by heating even after poisoning; as well as a honeycomb structure, a method for the decomposition of organic substances, and an apparatus for the decomposition of organic substances which use the catalyst for the decomposition of organic substances. Brief description of the drawings [ Fig. 1] Fig.Figure 1 is a schematic view of a device for the decomposition of organic substances according to the present invention. [ Fig. 2] Fig. Figure 2 shows the XRD measurement results for the catalysts for the decomposition of organic substances of examples 6, 10 and 19. [ Fig. 3] Fig. Figure 3 shows TEM (transmission electron microscope) images and EDX element distribution images (energy-dispersive X-ray spectroscopy) of the catalyst for the decomposition of organic substances from Example 10. [ Fig. 4] Fig. Figure 4 is a schematic view of a device used in the examples for the decomposition of organic substances. Description of embodiments

[0012] Catalysts for the decomposition of organic substances according to embodiments of the present invention are described below with reference to the drawings. In the following description of the embodiments, identical or equivalent parts in the drawings are designated with the same reference numerals, and their descriptions are not repeated.

[0013] A catalyst for the decomposition of organic substances according to the present invention serves for the oxidative decomposition of organic substances. The catalyst for the decomposition of organic substances contains a ternary mixed oxide (hereinafter also referred to as the "first oxide") containing zirconium (Zr), manganese (Mn), and neodymium (Nd). In this description, "ternary mixed oxide" refers to an oxide containing three elements in addition to oxygen and having a stable crystal structure.

[0014] The first oxide can be an oxide containing Zr, Mn, and Nd. The presence of the first oxide in the organic decomposition catalyst can be confirmed by X-ray diffraction analysis (XRD) or by elemental mapping using energy-dispersive X-ray spectroscopy (EDX) with a transmission electron microscope (TEM). XRD or TEM-EDX analysis confirms that the crystal structure of the first oxide is a mixed crystal in which Mn and Nd are dispersed and embedded within the crystal lattice of zirconium oxide (ZrO₂).

[0015] Examples of organic substances that are oxidatively decomposed by the organic decomposition catalyst include hydrocarbon gases, sulfur compounds, and nitrogen compounds. These organic substances can be, for example, volatile organic compounds (VOCs). The organic decomposition catalyst of the present invention is particularly suitable for the oxidative decomposition of hydrocarbon gases (e.g., aromatic hydrocarbons, alcohols, ketones, aldehydes, and carboxylic acids). The organic decomposition catalyst is used, for example, for the purification of harmful gases such as exhaust gases.

[0016] Oxidative decomposition is described using the example of the toluene combustion reaction, which is represented by the following formula (1): C7H8 + 902 → 4H2O + 7CO2 (1)

[0017] In this reaction, the harmful toluene, whose emission into the atmosphere is subject to restrictions, is converted into harmless water vapor and carbon dioxide upon reaction with air (oxygen). Since this reaction is exothermic, the reaction zone is heated to a high temperature, especially when treating highly concentrated or large quantities of gas. If the hydrocarbons that make up the hydrocarbon gases contain sulfur or chlorine elements in their organic structure, the sulfur or chlorine reacts with catalyst components or binds strongly to adsorption sites on the catalyst surface, leading to poisoning and consequently to a deterioration of the catalyst's performance.

[0018] Organic decomposition catalysts containing the first oxide tend to exhibit improved heat resistance. This may be because the simultaneous addition of Mn and Nd to ZrO₂ increases the number of active sites, thus improving the decomposition performance of organic substances, while the change in the surface energy of ZrO₂ inhibits crystallite growth and improves heat resistance. Consequently, the organic decomposition catalyst of the present invention tends to exhibit high catalytic activity even in its initial state, tends to retain high catalytic activity even after poisoning, and tends to be easily regenerated by heating even after poisoning, if it is calcined at high temperature (e.g., 900 °C) during the manufacturing process or used at high temperatures.The initial activity, the catalytic activity after poisoning, and the catalytic activity after regeneration are evaluated according to the methods described in the "Examples" section below.

[0019] An organic decomposition catalyst containing the first oxide can exhibit higher initial catalytic activity and maintain higher catalytic activity even after poisoning than an organic decomposition catalyst that does not contain the first oxide and contains a binary mixed oxide. For example, an organic decomposition catalyst containing the first oxide can exhibit higher initial catalytic activity and maintain higher catalytic activity even after poisoning than an organic decomposition catalyst that does not contain the first oxide and contains a binary mixed oxide of Zr and Mn, and than an organic decomposition catalyst that does not contain the first oxide and contains a binary mixed oxide of Nd and Zr.This is because the simultaneous addition of Mn and Nd to ZrO2, compared to a binary mixed oxide containing either Mn or Nd, allows Mn and Nd to be easily dispersed in ZrO2. This results in more active sites, leading to improved decomposition performance of organic substances and lowering the surface energy of ZrO2, which inhibits crystallite growth and improves heat resistance.

[0020] The catalyst for the decomposition of organic substances of the present invention can exhibit higher catalytic activity in the initial activity and maintain higher catalytic activity even after poisoning than a catalyst for the decomposition of organic substances that does not contain the first oxide and contains a mixture of a binary mixed oxide of Zr and Mn and a binary mixed oxide of Nd and Zr.

[0021] The catalyst for the decomposition of organic substances may contain, in addition to the first oxide, a second oxide exhibiting catalytic activity (hereinafter also referred to as the "second oxide"). The second oxide may, for example, contain one, two, or more oxides containing manganese or neodymium. The second oxide may be, for example, a single-component oxide or a binary mixed oxide. Specific examples of the second oxide include Mn3O4, Mn2O3, and Nd2O3. The catalyst for the decomposition of organic substances may contain only the first oxide or only the first oxide and the second oxide as its oxide-containing, catalytically active components.

[0022] The organic decomposition catalyst may consist solely of the first oxide or solely of the first and second oxides. The organic decomposition catalyst may contain a binder or an organic solvent to form particles or a honeycomb structure as described below, or to facilitate application to a structure. For example, the amount of the first oxide in the organic decomposition catalyst may be at most 100% by mass, at most 95% by mass, or at most 90% by mass, and at least 50% by mass, based on the mass of the organic decomposition catalyst.In a structure coated with the catalyst for the decomposition of organic substances, such as a honeycomb structure coated with the catalyst for the decomposition of organic substances as described below, the mass of the catalyst for the decomposition of organic substances refers to the mass of the catalyst coated on the structure and does not include the mass of the structure (e.g. honeycomb ceramic).

[0023] If the catalyst for the decomposition of organic substances contains the second oxide, the amount of the second oxide is, for example, at most 40 parts by weight, preferably at most 30 parts by weight, and is more than 0 parts by weight, in each case for every 100 parts by weight of the first oxide.

[0024] The molar ratio of Mn to Zr in the catalyst for the decomposition of organic substances is, for example, in the range of 0.02 to 1.00, preferably in the range of 0.05 to 0.70. If the molar ratio of Mn to Zr in the catalyst for the decomposition of organic substances is within the above range, the catalyst for the decomposition of organic substances exhibits improved heat resistance, and consequently, it tends to show high catalytic activity in the initial phase, tends to retain high catalytic activity even after poisoning, and tends to be easily regenerated even after poisoning by heating.

[0025] The molar ratio of Nd to Zr in the catalyst for the decomposition of organic substances is, for example, in the range of 0.002 to 0.200, preferably in the range of 0.010 to 0.150. If the molar ratio of Nd to Zr in the catalyst for the decomposition of organic substances is within the above range, the catalyst for the decomposition of organic substances exhibits improved heat resistance, and consequently, it tends to show high catalytic activity in the initial phase, tends to retain high catalytic activity even after poisoning, and tends to be easily regenerated even after poisoning by heating.

[0026] The organic decomposition catalyst may contain a monoclinic ZrO₂ crystal phase (first crystal phase). The first crystal phase may be a mixed crystal phase in which Mn and Nd are dispersed and embedded. In addition to the first crystal phase, the organic decomposition catalyst may contain one, two, or more crystal phases (second crystal phases). The second crystal phase may, for example, comprise a Mn₃O₄ crystal phase, a Mn₂O₃ crystal phase, an Nd₂O₃ crystal phase, a cubic ZrO₂ crystal phase, or a tetragonal ZrO₂ crystal phase. The organic decomposition catalyst can be identified by XRD analysis.

[0027] In the catalyst for the decomposition of organic substances, the molar ratio of manganese to zirconium can be 0.05 or more, and the molar ratio of neodymium to zirconium can be 0.01 or more, and if the (-111) plane diffraction peak intensity of monoclinic ZrO2 is designated A in the XRD analysis, the (011) plane diffraction peak intensity of Nd2O3 is designated B, the (103) plane diffraction peak intensity of Mn3O4 is designated C, and the (222) plane diffraction peak intensity of Mn2O3 or the (211) plane diffraction peak intensity of NdMnO3 is designated D, then (B + C + D) / A is 0.9 or less. With these characteristics, the catalyst for the decomposition of organic substances can maintain high activity even after calcination at 900 °C (the toluene 90% decomposition temperature is ≤ 350 °C).Due to its high heat resistance, a catalyst whose catalytic performance has deteriorated due to poisoning can be regenerated by heating. A catalyst containing at least predetermined amounts of Mn and Nd relative to the monoclinic ZrO₂ main phase exhibits improved catalytic activity. A catalyst containing excess Mn and Nd, according to XRD measurements, shows increased amounts of side phases such as Mn₃O₄, Mn₂O₃, NdMnO₃, and Nd₂O₃. The Mn and Nd in these side phases can reduce catalytic activity because, at high temperatures, they undergo grain growth instead of remaining dispersed on ZrO₂.If the ratio of the XRD peak intensity of the main phase (monocline ZrO2) to the total XRD peak intensity of the secondary phases (Mn3O4, Mn2O3, NdMnO3, and Nd2O3) (hereinafter referred to as the secondary / main phase peak ratio) is 0.9 or less according to the XRD measurement results, a decrease in activity can be easily suppressed. Quantities A, B, C, and D are determined according to the methods described in the "Examples" section.

[0028] The catalyst for the decomposition of organic substances can be produced, for example, as follows. First, abrasive media, water, and an organic binder are combined to form ZrO₂. zMn3O4 and Nd2O3 are added and mixed to obtain a mixture. Mixing can be done using a ball mill or similar equipment. Next, the mixture is dried in an oven at 120 °C, then milled and classified to obtain particles with a particle size ranging from a few hundred micrometers to several millimeters. The resulting sample in particle form is then calcined in air at 900 °C for 2 hours. This process yields the catalyst for the decomposition of organic substances.

[0029] The temperature at which the catalyst can exhibit catalytic activity for the decomposition of organic substances in the initial activity is, for example, 300 °C or higher and 510 °C or lower, preferably 310 °C or higher and 460 °C or lower.

[0030] The temperature at which the catalyst can exhibit catalytic activity for the decomposition of organic substances after poisoning is, for example, 400 °C or higher and 700 °C or lower, preferably 420 °C or higher and 620 °C or lower, and even more preferably 420 °C or higher and 540 °C or lower.

[0031] The temperature at which the catalyst for the decomposition of organic substances can exhibit catalytic activity after regeneration by heating is, for example, 300 °C or higher and 700 °C or lower, preferably 340 °C or higher and 540 °C or lower, and even more preferably 340 °C or higher and 470 °C or lower.

[0032] Since the organic decomposition catalyst exhibits improved heat resistance, can display high catalytic activity during initial activation, can maintain high catalytic activity even after poisoning, and can be regenerated by heating even after poisoning, it is suitable for the decomposition of volatile organic compounds (VOCs) generated in processes such as painting, molding, combustion, and waste disposal in residential and industrial environments, causing environmental pollution. The organic decomposition catalyst can be used for cleaning vehicle exhaust and for other applications.

[0033] Form of the Organic Decomposition Catalyst: The organic decomposition catalyst can be used, for example, as a pelletized catalyst with a particle size of several millimeters to several centimeters, or as a honeycomb catalyst obtained by forming it into a honeycomb shape. By coating the surface of a honeycomb-shaped ceramic with the organic decomposition catalyst, it can also be used as a honeycomb-coated structure. The honeycomb shape can reduce the pressure drop when gas flows through the structure. Increasing the cell density of the honeycomb structure increases the effective surface area and can thus slightly increase the decomposition rate of the organic matter.

[0034] A process for the decomposition of organic substances according to a further embodiment of the present invention is a process for the decomposition of organic substances comprising a decomposition step in which organic substances are oxidatively decomposed by heating the organic substances with the organic decomposition catalyst described above. In the decomposition step, the organic substances can be decomposed by heating them while they are in contact with the organic decomposition catalyst. The above description of the organic substances also applies to these organic substances. The process for the decomposition of organic substances can be carried out using the organic decomposition apparatus described below.

[0035] The heating temperature in the decomposition step is, for example, 300 °C or higher and 900 °C or lower. If the heating temperature in the decomposition step is within the above range, the catalyst can exhibit catalytic activity for the decomposition of organic substances and can also exhibit catalytic activity after poisoning. To suppress deterioration of the catalyst performance and reduce energy costs, the heating temperature in the decomposition step is preferably 300 °C or higher and 700 °C or lower, more preferably 300 °C or higher and 600 °C or lower, and particularly preferably 300 °C or higher and 540 °C or lower.

[0036] A method for heating organic substances while they are in contact with the organic decomposition catalyst can, for example, involve placing the organic decomposition catalyst into a tube, introducing the organic substances into the tube, and heating the contact area between the organic decomposition catalyst and the organic substances in the tube from outside the tube. The organic decomposition catalyst placed in the tube can be a pelletized catalyst, a honeycomb catalyst, or the honeycomb structure coated with the organic decomposition catalyst described above. The organic decomposition catalyst can also be an aggregate of the organic decomposition catalyst.

[0037] The process for decomposing organic substances may further include a regeneration step in which the catalytic activity is restored by heating the catalyst used in the decomposition step to a temperature higher than or equal to the heating temperature used in the decomposition step. The regeneration step can be carried out by heating the catalyst used in the decomposition step to a temperature higher than or equal to the heating temperature used in the decomposition step while keeping the catalyst in contact with air. The catalyst used in the decomposition step may have been poisoned by sulfur, chloride, phosphorus, or other elements.

[0038] The temperature, which is higher than or equal to the heating temperature in the decomposition step, is, for example, 300 °C or higher and 900 °C or lower. From the perspective of the catalytic activity of the regenerated catalyst and energy costs, the temperature is preferably 400 °C or higher and 800 °C or lower, and particularly preferably 600 °C or higher and 800 °C or lower.

[0039] A method for heating the catalyst used in the decomposition step for the decomposition of organic substances while the catalyst for the decomposition of organic substances is held in contact with air may, for example, consist of introducing air into the tube filled with the catalyst used in the decomposition step for the decomposition of organic substances and heating the catalyst for the decomposition of organic substances from outside the tube.

[0040] Device for the Decomposition of Organic Substances. A device for the decomposition of organic substances according to a further embodiment of the present invention comprises a tube through which organic substances flow and a heating device that heats the organic substances flowing through the tube. The catalyst for the decomposition of organic substances described above is arranged in a region located inside the tube and heated by the heating device.

[0041] The device for decomposing organic substances is described with reference to Fig. 1 described. One in Fig. The device 10 shown for the decomposition of organic substances comprises a tube 1 through which organic substances flow, a heating device 2 which heats the organic substances flowing through the tube 1, and a control device 3 which controls the heating device 2.

[0042] An organic decomposition catalyst 6 is arranged in a region located within the tube 1 and heated by the heating device 2. The organic decomposition catalyst 6 can be the organic decomposition catalyst described above, and the form of the organic decomposition catalyst 6 can be an aggregate or the pelletized catalyst, the honeycomb catalyst, or the honeycomb structure coated with the organic decomposition catalyst described above.

[0043] Pipe 1 has a gas inlet 4 on its upstream side. The gas inlet 4 is connected to a gas supply pipe 7. Upstream of pipe 1, the gas supply pipe 7 is connected to a supply line 41 for organic substances (for supplying organic substances, e.g., toluene), a nitrogen supply line 42 for supplying nitrogen (N2), and an oxygen supply line 43 for supplying oxygen (O2). More precisely, a gas to be treated, containing organic substances, nitrogen, and oxygen, is fed into pipe 1 via the gas supply pipe 7.

[0044] Pipe 1 has a reaction gas outlet 5 on its downstream side. The reaction gas outlet 5 is connected to the gas discharge pipe 8, through which the treated gas is discharged from the system after the organic substances in pipe 1 have been decomposed. The gas discharge pipe 8 is connected to a sampling line 51 for sampling the treated gas, thus enabling the analysis of the concentration of organic substances in the treated gas by gas chromatography.

[0045] The control unit 3 is configured to regulate the temperature of the area heated by the heating unit 2 to, for example, 300 °C or higher and 900 °C or lower.

[0046] The control unit 3 is configured to control the heating unit 2 such that the temperature of the organic decomposition catalyst 6 is 300 °C or higher and 900 °C or lower. Controlling the temperature of the organic decomposition catalyst 6 within the range of 300 °C or higher and 900 °C or lower can increase its catalytic activity. Controlling the temperature of the organic decomposition catalyst 6 at 900 °C or lower can suppress deterioration of the organic decomposition catalyst 6.

[0047] The organic decomposition catalyst 6 can be subjected to a regeneration treatment after the decomposition of organic substances to restore its catalytic activity. The regeneration treatment consists of introducing oxygen and nitrogen into tube 1 without the addition of organic substances and heating the organic decomposition catalyst 6 with the heating device 2, controlled by the control unit 3, such that the catalyst's temperature is higher than or equal to the heating temperature during the decomposition step. Since the regeneration treatment aims to desorb catalyst poisons by heating, the catalyst must be heated to a temperature higher than or equal to its operating temperature. The regeneration treatment can also be carried out with the addition of organic substances. EXAMPLES

[0048] The present invention is described in more detail below with reference to examples. Unless otherwise stated, "%" and "parts" in the examples represent mass percent and mass fractions, respectively. Analysis of the catalysts for the decomposition of organic substances in the examples and comparative examples described below by X-ray fluorescence analysis yielded the compositions of the catalysts for the decomposition of organic substances given in Tables 1 and 2. <Beispiel 1>

[0049] ZrO₂, Mn₃O₄, and Nd₂O₃ were used as starting materials for an organic decomposition catalyst and weighed out in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.002. Abrasive media, water, and an organic binder were then added to the starting materials and mixed. The resulting mixture was dried in an oven at 120 °C, then milled and classified to obtain particles ranging from 0.5 mm to 0.7 mm. The resulting particle sample was calcined in air at 900 °C for 2 hours to obtain an organic decomposition catalyst of Example 1. <Beispiel 2>

[0050] A catalyst for the decomposition of organic substances of Example 2 was prepared in the same way as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.005. <Beispiel 3>

[0051] A catalyst for the decomposition of organic substances of Example 3 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.010. <Beispiel 4>

[0052] A catalyst for the decomposition of organic substances of Example 4 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.020. <Beispiel 5>

[0053] A catalyst for the decomposition of organic substances of Example 5 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.050. <Beispiel 6>

[0054] A catalyst for the decomposition of organic substances of Example 6 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.100. <Beispiel 7>

[0055] A catalyst for the decomposition of organic substances of Example 7 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.150. <Beispiel 8>

[0056] A catalyst for the decomposition of organic substances of Example 8 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.200. <Beispiel 9>

[0057] A catalyst for the decomposition of organic substances of Example 9 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.02:0.100. <Beispiel 10>

[0058] A catalyst for the decomposition of organic substances of Example 10 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.05:0.100. <Beispiel 11>

[0059] A catalyst for the decomposition of organic substances of Example 11 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.15:0.100. <Beispiel 12>

[0060] A catalyst for the decomposition of organic substances of Example 12 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.20:0.100. <Beispiel 13>

[0061] A catalyst for the decomposition of organic substances of Example 13 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.40:0.100. <Beispiel 14>

[0062] A catalyst for the decomposition of organic substances of Example 14 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.70:0.100. <Beispiel 15>

[0063] A catalyst for the decomposition of organic substances of Example 15 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:1.00:0.100. <Beispiel 16>

[0064] A catalyst for the decomposition of organic substances of Example 16 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.02:0.002. <Beispiel 17>

[0065] A catalyst for the decomposition of organic substances of Example 17 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.02:0.150. <Beispiel 18>

[0066] A catalyst for the decomposition of organic substances of Example 18 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.40:0.002. <Beispiel 19>

[0067] A catalyst for the decomposition of organic substances of Example 19 was prepared in the same manner as in Example 1, with the difference that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.40:0.150. <Beispiel 20>

[0068] An organic decomposition catalyst of Example 20 was prepared by carrying out the same process as in Example 1, from mixing to calcination, except that ZrO2, Mn3O4 and Nd2O3 were used as starting materials for the organic decomposition catalyst and were weighed in such quantities that the molar ratio Zr:Mn:Nd was 1.00:0.10:0.250. <Vergleichsbeispiel 1>

[0069] BaCO3, ZrO2, and Mn3O4 were used as starting materials for an organic decomposition catalyst and weighed out in such quantities that the molar ratio Ba:Zr:Mn was 1.00:0.90:0.10. Abrasive media, water, and an organic binder were then added to the starting materials and mixed. The resulting mixture was dried in an oven at 120 °C, then milled and classified to obtain particles ranging from 0.5 mm to 0.7 mm. The resulting particle sample was calcined in air at 1000 °C for 2 hours to obtain an organic decomposition catalyst of Comparative Example 1. <Vergleichsbeispiel 2>

[0070] A catalyst for the decomposition of organic substances from Comparative Example 2 was produced by carrying out the same process as in Example 1, from mixing to calcination, with the difference that ZrO2 and Mn3O4 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Mn was 1.00:0.02. <Vergleichsbeispiel 3>

[0071] A catalyst for the decomposition of organic substances from Comparative Example 3 was produced by carrying out the same process as in Example 1, from mixing to calcination, with the difference that ZrO2 and Nd2O3 were used as starting materials for the catalyst for the decomposition of organic substances and were weighed in such quantities that the molar ratio Zr:Nd was 1.00:0.10. [Crystal phase identification]

[0072] The catalysts of the examples and comparison examples were ground in a mortar, and the crystal phases were identified by powder XRD (X-ray source: Cu-Kα1). The types of crystal phases detected in the catalysts of the examples and comparison examples are shown in Table 1.

[0073] [Measurement of the Secondary / Main Phase Peak Ratio] To quantify the amount of the secondary phase components Mn3O4, Mn2O3, NdMnO3, and Nd2O3 identified by powder XRD relative to the monoclinic ZrO2 main phase, the secondary / main phase peak ratio was calculated. This ratio is defined as the ratio of the sum of the diffraction peak intensities of the secondary phase components to the diffraction peak intensity of the main phase component. The values ​​calculated from the powder XRD results are given in Table 1. The maximum diffraction peak intensities of the following crystal planes were used as the diffraction peak intensities for the respective crystal phases. A: The diffraction peak intensity of the (-111) plane of the monoclinic ZrO2 phase at 2θ = 27.5 to 28.8° B: The diffraction peak intensity of the (103) plane of Nd2O3 at 2θ = 30.6 to 31.0° C: The diffraction peak intensity of the (103) plane of Mn3O4 at 2θ = 32.1 to 32.5° D: The diffraction peak intensity of the (222) plane of Mn2O3 or the diffraction peak intensity of the (211) plane of NdMnO3 at 2θ = 32.6 to 33.2° Table 1 Composition of the catalyst for the decomposition of organic substances Type of crystal phase Side-phase / main-phase peak ratio Molar ratio of Mn to Zr in the catalyst for the decomposition of organic substances Molar ratio of Nd to Zr in the catalyst for the decomposition of organic substances Example 1 0,1 0,002 m-ZrO2, Mn3O4 0,1 Example 2 0,1 0,005 m-ZrO2, Mn3O4 0,1 Example 3 0,1 0,01 m-ZrO2, Mn3O4 0,1 Example 4 0,1 0,02 m-ZrO2, Mn3O4 0,3 Example 5 0,1 0,05 m-ZrO2, NdMnO3 0,4 Example 6 0,1 0,1 m-ZrO2, NdMnO3 0, 6 Example 7 0,1 0,15 m-ZrO2, NdMnO3, Nd2O3 0,9 Example 8 0,1 0,2 m-ZrO2, NdMnO3, Nd2O3 1,7 Example 9 0,02 0,1 m-ZrO2, Nd2O3 0,5 Example 10 0,05 0,1 m-ZrO2 0,3 Example 11 0,15 0,1 m-ZrO2, NdMnO3 0, 6 Example 12 0,2 0,1 m-ZrO2, NdMnO3, Nd2O3 0, 6 Example 13 0, 4 0,1 m-ZrO2, Mn3O4, NdMnO3, Nd2O3 0,7 Example 14 0,7 0,1 m-ZrO2, Mn3O4, NdMnO3, Nd2O3 0,9 Example 15 1 0,1 m-ZrO2, Mn3O4, NdMnO3, Nd2O3 1,0 Example 16 0,02 0,02 m-ZrO2 0,2 Example 17 0,02 0,15 m-ZrO2, Nd2O3 0,8 Example 18 0,4 0,02 m-ZrO2, Mn3O4 0,4 Example 19 0, 4 0,15 m-ZrO2, c-ZrO2,Mn3O4, NdMnO3 0,8 Example 20 0,1 0,25 m-ZrO2, Mn3O4, NdMnO3, Nd2O3 1,7 Comparative example 1 0,11 - Perovskite structure - Comparative example 2 0,02 - m-ZrO2 - Comparative example 3 - 0,1 m-ZrO2, Nd2O3 -

[0074] As shown in Table 1, the monoclinic ZrO2 crystal phase (labeled m-ZrO2 in Table 1) was identified in the catalysts of Examples 1 to 20, and depending on the composition ratio, crystal phases such as Mn3O4, Mn2O3, Nd2O3, as well as the cubic or tetragonal ZrO2 crystal phase (labeled c-ZrO2 in Table 1) were also identified. Furthermore, the perovskite crystal phase was identified in the catalyst of Comparative Example 1.

[0075] The XRD measurement results for examples 6, 10 and 19 are in Fig.Figure 2 illustrates this. In the Zr-Mn-Nd-based catalyst according to Example 6, m-ZrO2, Mn2O3, and NdMnO3 were detected, but Nd2O3 and Mn3O4 were not. This suggests that the simultaneous addition of Mn and Nd to ZrO2 leads to the incorporation and highly dispersed incorporation of Nd and Mn into the monoclinic ZrO2 crystal phase. In the catalyst of Example 10, neither Nd2O3 nor Mn3O4 were detected. Mn3O3 and NdMnO3 were also not detected. This suggests that Nd and Mn are incorporated into the monoclinic ZrO2 crystal phase and highly dispersed. In the catalyst of Example 19 with excess Mn and Nd, crystal phases such as c-ZrO2 and Mn3O4 were also detected. This suggests that the addition of an excess of Mn and Nd leads to the formation of ZrO2 structures other than the monoclinic ZrO2 phase and that Mn and Nd are not dispersed.

[0076] Fig.Figure 3 shows the TEM image of the catalyst from Example 10 and the elemental distribution images of Zr, Mn, and Nd obtained by EDX (energy-dispersive X-ray spectroscopy) in the same field of view. The distributions of the Zr, Mn, and Nd elements present in the catalyst particles of Example 10 are consistent, indicating a solid solution structure in which Mn and Nd are dispersed and incorporated within the crystal lattice of zirconium oxide (ZrO2). [Assessment of initial catalyst activity]

[0077] The toluene combustion reaction was carried out using the catalysts from the examples and comparison examples. A catalyst for the decomposition of organic substances 103 (0.1 cm³) 3 ) was placed in reaction tube 101 of a in Fig.The apparatus 100 shown in section 4 for the decomposition of organic substances was filled and heated to a predetermined temperature by the heating device 102. Air containing 1000 ppm toluene was introduced via the gas inlet 104 at a flow rate of 580 cm³ / h. 3 / min. During the test, the gas was collected after the reaction via the reaction gas outlet 105, and the toluene concentration [ppm] at the outlet was measured by gas chromatography. The toluene decomposition rate was determined using the following formula: Toluene decomposition rate [%] = (1000 - toluene concentration at outlet) / 1000

[0078] The test was performed while the test temperature was increased in 10 °C increments from 200 °C, and the temperature at which the toluene decomposition rate reached 90% was defined as the "toluene 90% decomposition temperature". The results are shown in Table 2. [Assessment of catalytic activity after SO2 poisoning]

[0079] The catalysts in the examples and comparison examples were each subjected to SO2 poisoning treatment. The catalyst for the decomposition of organic substances 103 (0.1 cm³) 3 ) was placed in reaction tube 101 of the in Fig. The apparatus 100 shown in Figure 4 was filled with organic matter for decomposition and heated to 600 °C by the heating device 102. Air containing 50 ppm SO2 was introduced via the gas inlet 104 at a flow rate of 580 cm³ / h. 3 The catalyst was supplied with toluene at a rate of / min and held for 2 hours, after which it was cooled. The toluene 90% decomposition temperature was then measured for the catalyst treated after SO2 poisoning using the same procedure as in the "Evaluation of Initial Catalyst Activity". The results are shown in Table 2. [Assessment of catalytic activity after thermal regeneration]

[0080] The catalysts in the examples and comparison examples were each subjected to a poisoning treatment using the same procedure as in the "Evaluation of catalytic activity after SO2 poisoning". Subsequently, 0.1 cm 3 of the catalyst for the decomposition of organic substances 103 into the tube 1 of the in Fig. The device 100 shown in section 4 was filled with organic matter for decomposition and heated to 800 °C by the heating device 102. Air was supplied via the gas inlet 104 at a flow rate of 580 cm³ / h. 3 The toluene was fed in at a rate of / min and held for 0.5 hours, after which it was cooled. The “toluene 90% decomposition temperature” of the catalyst obtained after thermal regeneration was then measured using the same procedure as in the “Evaluation of Initial Catalyst Activity”. The results are shown in Table 2. <Beispiel 21>

[0081] Abrasive media, water, and an organic binder were added to the catalyst of Example 5, and the mixture was milled and blended to produce a catalyst suspension. A cordierite honeycomb body (200 cells per square inch) was immersed in the prepared catalyst suspension for 1 minute, followed by air purging to form a catalyst layer. The resulting honeycomb body was then dried in an oven at 120 °C and subsequently calcined at 800 °C for 2 hours to obtain a catalyst-coated honeycomb body of Example 21. The catalyst coating weight per volume of honeycomb body was 100 g / L. [Evaluation of the properties of the catalyst-coated honeycomb body]

[0082] The [evaluation of initial catalyst activity], [evaluation of catalytic activity after SO2 poisoning], and [evaluation of catalytic activity after thermal regeneration] were carried out under the same conditions as in Example 5, except that a 14-cell, 50 mm long honeycomb catalyst was cut out from the catalyst-coated honeycomb body of Example 21 for activity evaluation, and the catalyst-coated honeycomb body of Example 21 was used as a catalyst for the decomposition of organic substances 103. The results are presented in Table 2. Table 2 Composition of the catalyst for the decomposition of organic substances Toluene 90% decomposition temperature (°C) Molar ratio of Mn to Zrim catalyst for the decomposition of organic substances Molar ratio of Nd to Zrim catalyst for the decomposition of organic substances initial activity after poisoning after regeneration Example 1 0,10 0,002 440 540 460 Example 2 0, 10 0,005 400 510 420 Example 3 0, 10 0,010 350 470 380 Example 4 0, 10 0,020 320 450 350 Example 5 0, 10 0,050 310 440 350 Example 6 0,10 0,100 320 440 350 Example 7 0,10 0,150 350 470 380 Example 8 0, 10 0,200 380 510 420 Example 9 0,02 0,100 360 470 380 Example 10 0,05 0,100 340 460 370 Example 11 0,15 0,100 310 420 340 Example 12 0,20 0,100 310 420 340 Example 13 0,40 0,100 310 420 340 Example 14 0,70 0,100 330 440 360 Example 15 1,00 0,100 390 510 420 Example 16 0,02 0,020 360 470 380 Example 17 0,02 0,150 450 530 440 Example 18 0,40 0,020 350 500 350 Example 19 0,40 0,150 320 450 370 Example 20 0, 10 0,250 440 540 470 Example 21 0, 10 0,050 320 480 370 Comparative example 1 0,11 - 390 > 700 > 700 Comparative example 2 0,02 - 500 580 510 Comparative example 3 - 0,1 520 630 550

[0083] The catalysts in Examples 1 to 20 exhibited high initial catalytic activity, maintained high catalytic activity even after poisoning, and could be successfully regenerated by heating after poisoning. The organic decomposition catalyst in Comparison Example 1 showed a significant deterioration in decomposition performance due to SO₂ poisoning, and the toluene decomposition rate did not reach 90% even at 700 °C. The organic decomposition catalyst in Comparison Example 1 could not regain its catalytic activity even after regeneration at 800 °C. In Comparison Examples 2 and 3, neither the initial activity, nor the activity after poisoning, nor the activity after thermal regeneration exhibited high catalytic activity.

[0084] In the catalyst-coated honeycomb structure of Example 21, poisoning progresses from the surface of the coating layer directly exposed to the flowing gas. Therefore, after poisoning, the catalyst-coated honeycomb structure of Example 21 tends to exhibit lower activity than the particle catalyst (Example 5). However, the catalyst-coated honeycomb structure of Example 21 and the particle catalyst (Example 5) showed similar properties with respect to initial activity and recovery by regeneration treatment. The honeycomb catalyst can reduce the pressure drop during gas flow reactions. For the particle catalyst (Example 5), the pressure drop increased to 6 kPa during the activity evaluation. For the catalyst-coated honeycomb structure (Example 21), the pressure drop could be successfully maintained at 1 kPa or less.

[0085] In the description of the embodiments described above, combinable configurations can be combined with one another.

[0086] The embodiments disclosed herein serve in every respect for illustration and should not be interpreted as limiting. The scope of this disclosure is defined by the claims and not by the above description and is intended to include all modifications that are within the meaning and scope of the equivalence of the claims.

[0087] It will be clear to experts that the exemplary embodiments described above are specific examples of the aspects listed below.

[0088] (Element 1) A catalyst for the oxidative decomposition of organic substances according to one aspect of the present invention, wherein the catalyst for the decomposition of organic substances comprises a ternary mixed oxide containing zirconium, manganese and neodymium.

[0089] (Element 2) The catalyst for the decomposition of organic substances according to Element 1, wherein the molar ratio of manganese to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.02 to 1.00.

[0090] (Element 3) The catalyst for the decomposition of organic substances according to Element 1, wherein the molar ratio of manganese to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.05 to 0.70.

[0091] (Element 4) The catalyst for the decomposition of organic substances according to one of elements 1 to 3, wherein the molar ratio of neodymium to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.002 to 0.200.

[0092] (Element 5) The catalyst for the decomposition of organic substances according to one of elements 1 to 3, wherein the molar ratio of neodymium to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.010 to 0.150.

[0093] (Element 6) The catalyst for the decomposition of organic substances according to one of elements 1 to 5, wherein the catalyst for the decomposition of organic substances contains a monoclinic zirconium oxide crystal phase.

[0094] (Element 7) The catalyst for the decomposition of organic substances according to one of elements 1 to 6, wherein in the catalyst for the decomposition of organic substances, the molar ratio of manganese to zirconium is 0.05 or more and the molar ratio of neodymium to zirconium is 0.01 or more, and when the (-111)-plane diffraction peak intensity of monoclinic ZrO2 is designated as A in XRD analysis, the (011)-plane diffraction peak intensity of Nd2O3 is designated as B, the (103)-plane diffraction peak intensity of Mn3O4 is designated as C, and the (222)-plane diffraction peak intensity of Mn2O3 or the (211)-plane diffraction peak intensity of NdMnO3 is designated as D, (B + C + D) / A is 0.9 or less.

[0095] (Element 8) A honeycomb structure coated with the catalyst for the decomposition of organic substances according to one of elements 1 to 7.

[0096] (Element 9) A process for the decomposition of organic substances, comprising: a decomposition step in which organic substances are oxidatively decomposed by heating the organic substances with the catalyst for the decomposition of organic substances according to one of the elements 1 to 7.

[0097] (Element 10) The process for the decomposition of organic substances according to Element 9, further comprising: a regeneration step in which catalytic activity is restored by heating the catalyst used in the decomposition step to a temperature higher than or equal to the heating temperature in the decomposition step.

[0098] (Element 11) A device for the decomposition of organic substances, comprising: a pipe through which organic substances flow; and a heating device that heats the organic substances flowing through the pipe; wherein the catalyst for the decomposition of organic substances according to one of the elements 1 to 7 is arranged in a region which is located inside the tube and is heated by the heating device. Reference symbol list 1 pipe 2 Heating system 3 Control unit 4, 104 Gas inlet 5, 105 Reaction gas outlet 6, 103 Catalyst for the decomposition of organic substances 7 Gas supply pipe 8 Gas discharge pipe 10, 100 Device for the decomposition of organic substances 41 Supply line for organic substances 42 Nitrogen supply line 43 Oxygen supply line 51 Sampling line 101 Reaction tube 102 Heating system QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-229137

[0003] CH 111790374

[0003] Cited non-patent literature

[0000] Jose I. Gutierrez-Ortiz et al., „Structure of Mn-Zr mixed oxides catalysts and their catalytic performance in the gas-phase oxidation of chlorocarbons,“ Chemosphere, 2007, Vol. 68, S. 1004-1012

[0003] D. Doebber et al., „MnOx / ZrO2 catalysts for the total oxidation of methane and chloromethane,“ Applied Catalysis B: Environmental, 2004, Vol. 52, S. 135-143

[0003]

Claims

[1] Catalyst for the oxidative decomposition of organic substances, comprising: a ternary mixed oxide containing zirconium, manganese and neodymium. [2] Catalyst for the decomposition of organic substances according to claim 1, wherein the molar ratio of manganese to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.02 to 1.

00. [3] Catalyst for the decomposition of organic substances according to claim 1, wherein the molar ratio of manganese to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.05 to 0.

70. [4] Catalyst for the decomposition of organic substances according to any one of claims 1 to 3, wherein the molar ratio of neodymium to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.002 to 0.

200. [5] Catalyst for the decomposition of organic substances according to any one of claims 1 to 3, wherein the molar ratio of neodymium to zirconium in the catalyst for the decomposition of organic substances is in the range of 0.010 to 0.

150. [6] Catalyst for the decomposition of organic substances according to any one of claims 1 to 5, wherein the catalyst for the decomposition of organic substances comprises a monoclinic zirconium oxide crystal phase. [7] Catalyst for the decomposition of organic substances according to any one of claims 1 to 6, wherein in the catalyst for the decomposition of organic substances, the molar ratio of manganese to zirconium is 0.05 or more and the molar ratio of neodymium to zirconium is 0.01 or more, and when a (-111)-plane diffraction peak intensity of monoclinic ZrO2 in XRD is designated as A, a (011)-plane diffraction peak intensity of Nd2O3 is designated as B, a (103)-plane diffraction peak intensity of Mn3O4 is designated as C, and a (222)-plane diffraction peak intensity of Mn2O3 or a (211)-plane diffraction peak intensity of NdMnO3 is designated as D, (B + C + D) / A equals 0.9 or less. [8] Honeycomb structure coated with the catalyst for the decomposition of organic substances according to any one of claims 1 to 7. [9] Processes for the decomposition of organic substances, comprising: a decomposition step in which organic substances are oxidatively decomposed by heating the organic substances with the catalyst for the decomposition of organic substances according to one of claims 1 to 7. [10] Method for the decomposition of organic substances according to claim 9, further comprising: a regeneration step in which catalytic activity is restored by heating the catalyst used in the decomposition step to a temperature higher than or equal to the heating temperature in the decomposition step. [11] Device for the decomposition of organic substances, comprising: a pipe through which organic substances flow; and a heating device that heats the organic substances flowing through the pipe; wherein the catalyst for the decomposition of organic substances according to one of claims 1 to 7 is arranged in a region which is located inside the tube and is heated by the heating device.

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