A honeycomb catalyst containing spinel-type non-noble metal oxides, a preparation method thereof, and use thereof

Abstract

This invention relates to a honeycomb catalyst containing spinel-type non-noble metal oxides, its preparation method, and its applications. The honeycomb catalyst of this invention avoids or mitigates the aggregation of catalyst components, thereby improving the catalytic activity of the honeycomb catalyst. Furthermore, the honeycomb catalyst of this invention exhibits excellent sulfur resistance and compressive strength. Moreover, the honeycomb catalyst of this invention does not have a coated active component layer, avoiding the problem of easy detachment of the active component layer. This invention also relates to the preparation method and applications of the honeycomb catalyst.

Description

Technical Field

[0001] This invention relates to catalysts for the degradation of volatile organic compounds (VOCs), specifically to a honeycomb catalyst containing spinel-type non-noble metal oxides, its preparation method, and its application. Background Technology

[0002] With increasingly stringent regulations on volatile organic compound (VOC) emissions, VOCs treatment has received significant attention. Catalytic oxidation technology is one method for degrading VOCs. Catalytic oxidation technology, under the action of a catalyst, completely converts VOCs into CO2 and H2O. It is considered the most effective method for VOCs degradation. Catalysts used in catalytic oxidation technology can include noble metal catalysts and non-noble metal catalysts. Noble metal catalysts suffer from disadvantages such as high cost, scarcity, susceptibility to poisoning, and high-temperature sintering and deactivation. Non-noble metal catalysts are mainly composed of transition metal oxides. Non-noble metal catalysts have advantages such as abundant availability and low cost, but suffer from disadvantages such as lower activity and higher ignition temperatures. Especially when treating sulfur-containing organic gases, some non-noble metal catalysts also exhibit poor sulfur resistance. It has been found that spinel-structured (AB2O4) non-noble metal catalysts possess high oxygen mobility, strong redox performance, and high stability. This structure can not only effectively improve the catalytic performance and lower the ignition temperature, but also improve the catalyst's sulfur resistance.

[0003] CN108889301A discloses a spinel-type iron-based catalyst and its preparation method. The method involves doping iron (AFe₂O₄) with alumina (A) using a sol-gel method, which improves the catalyst's reactivity and sulfur resistance. However, the preparation of this catalyst involves a high-temperature calcination step to form the doped spinel structure. This can cause a certain degree of agglomeration of the catalyst components, thus affecting the catalyst's performance.

[0004] CN112337460A discloses a method for preparing a Mn-based spinel-phase low-temperature denitration catalyst. The method includes the steps of: obtaining an Mn-based spinel-phase catalyst active component by complexing an acid solution, forming it using silicon-aluminum spheres as a carrier by roll coating, and calcining it to obtain the Mn-based spinel catalyst. The method also includes high-temperature calcination, which leads to the agglomeration of the catalyst components.

[0005] Therefore, how to effectively suppress the agglomeration of catalyst components in catalysts containing spinel-type non-precious metal oxides is one of the technical problems that we hope to solve in this field.

[0006] Furthermore, non-precious metal catalysts require molding to ensure their mechanical strength. This molding typically involves coating the active component onto a honeycomb support (e.g., cordierite) and then calcining it to obtain a monolithic catalyst. However, the resulting monolithic catalyst may experience problems during use, such as poor interfacial bonding between the catalyst's active component and the honeycomb support, poor erosion resistance, and even the detachment of the active component coating. Summary of the Invention

[0007] To address one or more of the problems existing in the prior art, the present invention provides a honeycomb catalyst containing spinel-type non-noble metal oxides. The honeycomb catalyst of the present invention avoids or mitigates the agglomeration of catalyst components, thereby improving the catalytic activity of the honeycomb catalyst. Furthermore, the honeycomb catalyst of the present invention exhibits excellent sulfur resistance and compressive strength. Moreover, the honeycomb catalyst of the present invention does not have a coated active component layer, avoiding the problem of easy detachment of the active component layer. The present invention also relates to a method for preparing the honeycomb catalyst and its applications.

[0008] In one aspect, the present invention provides a honeycomb catalyst containing a spinel-type non-precious metal oxide, comprising (1) fibrous silicate clay, (2) AB2O4 spinel-type oxide, and (3) a rare earth mineral containing lanthanum or cerium, wherein the fibrous silicate clay comprises at least one of attapulgite, halloysite, wollastonite, or sepiolite, wherein A and B are different non-precious metals and are each selected from at least one of nickel, cobalt, iron, manganese, titanium, or copper, and wherein the rare earth mineral containing lanthanum or cerium comprises at least one of monazite, lanthanum phosphite, or bastnaesite.

[0009] In one aspect, the present invention provides a method for preparing the above-mentioned honeycomb catalyst, comprising the steps of:

[0010] (1) Provide organic acid-modified fibrous silicate clay;

[0011] (2) Mix organic acid-modified fibrous silicate clay, water, water-soluble salt of A and water-soluble salt of B, and dry the mixture to obtain a dry gel-like composite.

[0012] (3) The dry gel-like composite from step (2), rare earth minerals containing lanthanum or cerium, and extrusion aids are mixed, and the mixture is shaped, dried, and calcined to obtain the honeycomb catalyst.

[0013] In one aspect, the present invention relates to the application of the aforementioned honeycomb catalyst in the degradation of volatile organic compounds.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] (1) The fibrous silicate clay was modified with organic acid and the organic acid was solidified on the surface of the fibrous silicate clay. The solidified organic acid can act as a complexing agent, which helps to adsorb and deposit non-precious metal ions from water-soluble salts on the fibrous silicate clay, and uniformly form particles containing non-precious metal catalyst components in situ, avoiding their agglomeration.

[0016] (2) The dry gel-like composite is a complex of AB₂O₄ spinel precursor and fibrous silicate clay. It is mixed with lanthanum- or cerium-containing rare earth minerals, shaped, and calcined to prepare a honeycomb catalyst. This process facilitates the effective doping of rare earth elements into the AB₂O₄ spinel oxide during the formation of the honeycomb catalyst, thereby significantly increasing the number of active oxygen vacancies. Furthermore, both the AB₂O₄ spinel oxide and the lanthanum- or cerium-containing rare earth minerals possess certain catalytic properties and sulfur resistance. The combination of these two components produces a synergistic effect, resulting in a final honeycomb catalyst with superior catalytic performance and sulfur resistance.

[0017] (3) Fibrous silicate clay is used as a support to load other catalyst components, such as AB2O4 spinel-type oxides. Fibrous silicate clay has excellent reinforcing, toughening and bonding properties, thereby improving the mechanical strength of the honeycomb catalyst.

[0018] (4) The preparation method of the present invention does not require the step of coating an active component layer used in the traditional method, which simplifies the process, shortens the production cycle, and reduces the manufacturing cost. Attached Figure Description

[0019] Figure 1 A photograph of the honeycomb catalyst (28 mm in diameter, 14 mm in height) of Example 4 is shown;

[0020] Figure 2 The XRD pattern of the dry gel-like complex in Example 4;

[0021] Figure 3 The XRD pattern of the dry gel-like complex in Comparative Example 4 is shown.

[0022] Figure 4 The XRD spectrum of attapulgite;

[0023] Figure 5 This is a TEM image of the dry gel-like complex in Example 4;

[0024] Figure 6 This is a TEM image of the dry gel-like complex in Comparative Example 1. Detailed Implementation

[0025] In this document, percentages and percentage contents are all expressed by mass unless otherwise expressly stated.

[0026] Except in the embodiments, all numerical values ​​of parameters herein should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numerical value.

[0027] In one aspect, the present invention provides a honeycomb catalyst containing a spinel-type non-precious metal oxide, comprising (1) fibrous silicate clay, (2) AB2O4 spinel-type oxide, and (3) a rare earth mineral containing lanthanum or cerium, wherein the fibrous silicate clay comprises at least one of attapulgite, halloysite, wollastonite, or sepiolite, wherein A and B are different non-precious metals and are each selected from at least one of nickel, cobalt, iron, manganese, titanium, or copper, and wherein the rare earth mineral containing lanthanum or cerium comprises at least one of monazite, lanthanum phosphite, or bastnaesite.

[0028] In this document, "fibrous" refers to a shape whose length is much greater than its diameter. In one embodiment, the fibrous silicate clay has a diameter of 20-40 nm and a length of 0.5-5.0 μm.

[0029] In one embodiment, the mass ratio of AB2O4 spinel oxide to fibrous silicate clay is 0.08-0.30:1, and the total amount of AB2O4 spinel oxide and fibrous silicate clay is in the mass ratio of lanthanum- or cerium-containing rare earth minerals to 0.5-2.0:1.

[0030] Preferably, the honeycomb catalyst is substantially composed of or consists of the following components: (1) fibrous silicate clay, (2) AB2O4 spinel-type oxide, and (3) rare earth minerals containing lanthanum or cerium.

[0031] In one aspect, the present invention provides a method for preparing the above-mentioned honeycomb catalyst, comprising the steps of:

[0032] (1) Provide organic acid-modified fibrous silicate clay;

[0033] (2) Mix organic acid-modified fibrous silicate clay, water, water-soluble salt of A and water-soluble salt of B, and dry the mixture to obtain a dry gel-like composite.

[0034] (3) The dry gel-like composite from step (2), rare earth minerals containing lanthanum or cerium, and extrusion aids are mixed, and the mixture is shaped, dried, and calcined to obtain the honeycomb catalyst.

[0035] In one embodiment, providing the organic acid-modified fibrous silicate clay in step (1) includes the steps of applying an isocyanate silane coupling agent and an organic acid to the fibrous silicate clay. Preferably, providing the organic acid-modified fibrous silicate clay includes the steps of applying an isocyanate silane coupling agent to the fibrous silicate clay, wherein the mass ratio of the isocyanate silane coupling agent to the fibrous silicate clay is 0.05-0.15:1; and applying an organic acid to the fibrous silicate clay, wherein the mass ratio of the organic acid to the fibrous silicate clay is 0.05-0.2:1. Optionally, after applying the organic acid, the organic acid-modified fibrous silicate clay is kept at a temperature of 60°C-80°C for 30-90 minutes.

[0036] In one embodiment, the isocyanate silane coupling agent is at least one selected from 3-isocyanopropyltrimethoxysilane or 3-isocyanopropyltriethoxysilane. The organic acid is either citric acid or tartaric acid.

[0037] In one embodiment, step (2) of mixing organic acid-modified fibrous silicate clay, water, water-soluble salts A and B comprises the steps of: dispersing the organic acid-modified fibrous silicate clay in water, wherein the mass ratio of the organic acid-modified fibrous silicate clay to water is 0.05-0.2:1; and adding water-soluble salts A and B in amounts such that the mass ratio of AB2O4 spinel oxide to fibrous silicate clay in the resulting honeycomb catalyst is 0.08-0.30:1. Subsequently, the mixture is dried to obtain a dry gel-like composite. For example, the mixture can be evaporated at 85°C-95°C, dried at 110°C-140°C for 1-3 hours, and pulverized to obtain the dry gel-like composite. The dry gel-like composite contains an AB2O4 spinel oxide precursor and fibrous silicate clay. Specifically, the dry gel-like composite is a composite of an AB2O4 spinel oxide precursor and fibrous silicate clay.

[0038] In one embodiment, the water-soluble salt of A is at least one of the nitrate, hydrochloride, sulfate, or acetate of A, and the water-soluble salt of B is at least one of the nitrate, hydrochloride, sulfate, or acetate of B.

[0039] This invention does not impose any particular limitation on extrusion aids, and commonly used extrusion aids in the art can be used. Examples of extrusion aids include, but are not limited to, one or more polyols, cellulose, and carbon materials, preferably C2-12 polyols, more preferably ethylene glycol, diethylene glycol, triethylene glycol, and glycerol, and even more preferably glycerol. To achieve good dispersion of the extrusion aid, a polar dispersant is typically used to dissolve or disperse it. Polar dispersants include, but are not limited to, one or more of water, methanol, ethanol, propanol, butanol, and pentanol. An aqueous liquid or dispersion of the dispersant is preferred. In one variation, an aqueous solution of glycerol with a mass concentration of 10-100%, preferably 25-100%, is used as the extrusion aid. In one embodiment, step (3) of mixing the dry gel-like composite from step (2), the lanthanum- or cerium-containing rare earth mineral, and the extrusion aid includes the following steps: kneading the dry gel-like composite from step (2), the lanthanum- or cerium-containing rare earth mineral, and an aqueous solution of glycerol for 30-90 minutes, wherein the mass ratio of the dry gel-like composite to the lanthanum- or cerium-containing rare earth mineral is 0.5-2.0:1 and the mass ratio of glycerol to the dry gel-like composite is 0.05-0.1:1, and the mass percentage concentration of the aqueous glycerol solution is 25-100%; and performing a kneading process 4-6 times. Subsequently, the mixture is shaped, dried, and calcined to obtain the honeycomb catalyst. For example, the mixture is shaped from an extruder, dried at 90°C-120°C for 30-60 minutes, and calcined at 550°C-750°C for 2-8 hours to obtain the honeycomb catalyst. In one variation, the extruder has a honeycomb die, such as a circular honeycomb die with a diameter of 28 mm. In one variation, drying is performed by microwave drying at 90℃-120℃ for 30-60 minutes.

[0040] In one aspect, the present invention relates to the application of the aforementioned honeycomb catalyst in the degradation of volatile organic compounds.

[0041] In one embodiment, the degradation of the volatile organic compounds includes filling a reactor with the honeycomb catalyst, introducing a gas containing the volatile organic compounds into the reactor, and maintaining a gas space velocity of 4000-25000 h⁻¹. -1 The reaction is carried out at a temperature of 150-550℃ to remove volatile organic compounds from the gas.

[0042] Example

[0043] The present invention will be described in detail below through embodiments. These embodiments are intended to describe, and not to limit, the invention in any way.

[0044] Example 1

[0045] Under stirring, 0.25 kg of 3-isocyanate-propyltrimethoxysilane was applied to 5.0 kg of fibrous halloysite, and then 0.25 kg of citric acid was applied to the halloysite. The mixture was kept at 80 °C for 30 minutes to obtain citric acid-modified halloysite.

[0046] 1.0 kg of citric acid-modified halloysite was dispersed in 20.0 kg of deionized water, while 0.36 kg of cobalt nitrate and 0.18 kg of nickel nitrate were added and stirred until completely dissolved. The mixture was heated to 85 °C to evaporate the water, dried at 110 °C for 3 hours, and then pulverized to obtain a dry gel-like composite containing a NiCo2O4 spinel precursor and halloysite.

[0047] A mixture of 1.0 kg of a dry gel-like composite, 2.0 kg of lanthanum zinc phosphate ore, and 0.60 kg of an aqueous solution of glycerol (glycerol mass concentration 25%) was kneaded in a kneader for 30 minutes, and then kneaded four times in a vacuum pumice mill. The mixture was extruded from a molding extruder into a honeycomb shape, microwave-dried at 90°C for 60 minutes, and calcined at 550°C for 4 hours to obtain a honeycomb catalyst.

[0048] Example 2

[0049] Under stirring, 0.75 kg of 3-isocyanate-propyltriethoxysilane was applied to 5.0 kg of wollastonite, and then 1.0 kg of tartaric acid was applied to the wollastonite. The mixture was kept at 60 °C for 90 minutes to obtain tartaric acid-modified wollastonite.

[0050] 1.0 kg of tartaric acid-modified wollastonite was dispersed in 5.0 kg of deionized water, while 0.067 kg of manganese chloride and 0.036 kg of copper chloride were added and stirred until completely dissolved. The mixture was heated to 95 °C to evaporate the water, dried at 140 °C for 1 hour, and then pulverized to obtain a dry gel-like composite containing CuMn2O4 spinel precursor and wollastonite.

[0051] A mixture of 1.0 kg of a dry gel-like composite, 0.5 kg of bastnaesite, and 0.47 kg of an aqueous solution of glycerol (glycerol mass concentration 32%) was kneaded in a kneader for 90 minutes, and then kneaded five times in a vacuum pumice machine. The mixture was extruded from an extruder into a honeycomb shape, microwave-dried at 120 °C for 30 minutes, and calcined at 750 °C for 2 hours to obtain a honeycomb catalyst.

[0052] Example 3

[0053] Under stirring, 0.5 kg of 3-isocyanate-propyltrimethoxysilane was applied to 5.0 kg of sepiolite, and then 0.63 kg of tartaric acid was applied to the sepiolite. The mixture was kept at 70°C for 60 minutes to obtain tartaric acid-modified sepiolite.

[0054] 1.0 kg of tartaric acid-modified sepiolite was dispersed in 8.0 kg of deionized water, while 0.161 kg of manganese chloride and 0.113 kg of cobalt acetate were added and stirred until completely dissolved. The mixture was heated to 93 °C to evaporate the water, dried at 125 °C for 2 hours, and then pulverized to obtain a dry gel-like composite containing CoMn2O4 spinel precursor and sepiolite.

[0055] A mixture of 1.0 kg of a dry gel-like composite, 0.8 kg of monazite, and 0.44 kg of an aqueous solution of glycerol (glycerol mass concentration 32%) was kneaded in a kneader for 60 minutes, and then kneaded six times in a vacuum pumice mill. The mixture was extruded from a molding extruder into a honeycomb shape, microwave-dried at 105 °C for 45 minutes, and calcined at 650 °C for 3 hours to obtain a honeycomb catalyst.

[0056] Example 4

[0057] Under stirring, 0.4 kg of 3-isocyanate-propyltriethoxysilane was applied to 5.0 kg of attapulgite, and then 0.5 kg of citric acid was applied to the attapulgite. The mixture was kept at 75°C for 45 minutes to obtain citric acid-modified attapulgite.

[0058] 1.0 kg of citric acid-modified attapulgite was dispersed in 10.0 kg of deionized water, while 0.239 kg of ferric nitrate and 0.093 kg of copper nitrate were added and stirred until completely dissolved. The mixture was heated to 90 °C to evaporate the water, dried at 130 °C for 1.5 hours, and then pulverized to obtain a dry gel-like composite containing CuFe2O4 spinel precursor and attapulgite.

[0059] The dry gel-like composite was subjected to XRD and TEM tests. The test results showed... Figure 2 and Figure 5 Specifically, XRD tests were performed using a Rigaku D / max 2500PC X-ray diffractometer (Japan). Test conditions included: Cu K a Radiation was applied at a wavelength λ = 1.5406 nm, with a tube current of 30 mA and a tube voltage of 40 kV. TEM testing was performed using a JEOL JEM-2100 transmission electron microscope (JEOL, Japan). Test conditions included a voltage of 200 kV. The sample was ultrasonically dispersed in anhydrous ethanol, and after thorough ultrasonic agitation, it was pipetted onto the copper mesh surface and dried before testing.

[0060] like Figure 2 The results show that the dry gel-like composite exhibits diffraction peaks at 2θ values ​​of 8.6°, 30.03°, 35.41°, 38.75°, 43.07°, 57.04°, and 62.57°.

[0061] For comparison, in Figure 3 and Figure 4 The XRD patterns of the CuFe2O4 precursor and attapulgite are also given. Figure 3 As shown, the CuFe₂O₄ precursor exhibits sharp diffraction peaks at 2θ values ​​of 30.03°, 35.41°, 38.75°, 43.07°, 57.04°, and 62.57°; and as... Figure 4 As shown, attapulgite has a diffraction peak at 2θ = 8.6°.

[0062] The XRD pattern of the dry gel composite shows diffraction peaks for both the CuFe₂O₄ precursor and attapulgite. This indicates that the dry gel composite contains both CuFe₂O₄ precursor and attapulgite.

[0063] from Figure 5 It can be seen that the CuFe2O4 precursor is uniformly loaded on the surface of fibrous attapulgite clay, rather than agglomerating. This structure can be attributed to the fact that the citric acid complexing agent is solidified on the attapulgite surface, which facilitates the in-situ adsorption and deposition of non-precious metal ions on the attapulgite surface and uniformly forms active ingredient particles in situ, avoiding their agglomeration. Figure 5 It is clearly shown that attapulgite and CuFe2O4 spinel precursor are well composited together, that is, the prepared dry gel-like composite is a composite of CuFe2O4 precursor and attapulgite.

[0064] A mixture of 1.0 kg of a dry gel-like composite, 1.5 kg of monazite, and 0.50 kg of an aqueous solution of glycerol (40% glycerol concentration) was kneaded in a kneader for 50 minutes, and then kneaded six times in a vacuum pumice machine. The mixture was extruded from a molding extruder into a honeycomb shape, microwave-dried at 100°C for 50 minutes, and calcined at 700°C for 3 hours to obtain a honeycomb catalyst.

[0065] Comparative Example 1

[0066] Example 4 was repeated to obtain a honeycomb catalyst, except that the citric acid-modified attapulgite was prepared as follows:

[0067] Under stirring, 0.5 kg of citric acid was applied to 5.0 kg of attapulgite and kept at 75°C for 45 minutes to obtain citric acid-modified attapulgite.

[0068] As described above, a TEM image of the dry gel-like complex of Comparative Example 1 was obtained, such as... Figure 6 As shown.

[0069] from Figure 6 It can be seen that the CuFe2O4 precursor particles are relatively large and exhibit agglomeration, rather than being loaded onto the surface of the attapulgite clay. Through... Figure 5 and Figure 6 The comparison shows the importance of curing citric acid complexing agents onto the surface of attapulgite using silane coupling agents.

[0070] Comparative Example 2

[0071] Example 4 was repeated to obtain a honeycomb catalyst, except that the preparation of the dry gel-like complex was replaced with the following steps:

[0072] 1.0 kg of citric acid-modified attapulgite was dispersed in 10.0 kg of deionized water, while 0.239 kg of ferric nitrate and 0.093 kg of copper nitrate were added and stirred until completely dissolved. The mixture was heated to 90 °C to evaporate the water, and then dried at 130 °C for 1.5 hours to obtain a dry gel-like composite containing CuFe₂O₄ spinel precursor and attapulgite. The dry gel-like composite was calcined at 700 °C for 3 hours and then pulverized to obtain a composite containing CuFe₂O₄ spinel and attapulgite.

[0073] Comparative Example 3

[0074] Example 4 was repeated to obtain a honeycomb catalyst, except that monazite was not added.

[0075] Comparative Example 4

[0076] 0.5 kg of citric acid was dissolved in 10.0 kg of deionized water, and 0.239 kg of ferric nitrate and 0.093 kg of copper nitrate were added simultaneously. The mixture was stirred until completely dissolved. The mixture was heated to 90 °C to evaporate the water, dried at 130 °C for 1.5 hours, and then pulverized to obtain a dry gel-like composite material composed of CuFe2O4 spinel precursor.

[0077] XRD analysis of the dry gel-like complex showed that... Figure 3 In the middle. For example Figure 3 As shown, the dry gel-like composite exhibits sharp diffraction peaks at 2θ values ​​of 30.03°, 35.41°, 38.75°, 43.07°, 57.04°, and 62.57°.

[0078] The dry gel-like composite prepared in all the above steps, 1.5 kg of monazite, and 0.5 kg of an aqueous solution of glycerol (glycerol mass concentration 40%) were mixed and kneaded in a kneader for 50 minutes, and then kneaded 6 times in a vacuum pumice machine. The mixture was extruded from a molding extruder into a honeycomb shape, microwave-dried at 100°C for 50 minutes, and calcined at 700°C for 3 hours to obtain a honeycomb catalyst.

[0079] Catalyst performance evaluation

[0080] Catalytic performance: Using a gas containing p-xylene as a VOCs simulation gas, catalytic oxidation was performed in the presence of the catalyst sample to test the catalytic performance of the sample. Specifically, the catalyst sample was packed into a VOC adsorption-desorption catalytic reactor. A p-xylene-containing gas was generated by bubbling p-xylene solvent with nitrogen at room temperature. High-purity air was used as the carrier gas to carry the p-xylene-containing gas through the VOC adsorption-desorption catalytic reactor. The p-xylene concentration was controlled by adjusting the flow rates of nitrogen and the carrier gas used for bubbling. Specifically, the high-purity air flow rate was 450 mL / min and the nitrogen flow rate was 30 mL / min, resulting in a p-xylene concentration of 5000 mg / m³. 3 The concentration of p-xylene at the reactor outlet was analyzed online using a GC-2014 gas chromatograph, and the p-xylene conversion rate was calculated based on this. The p-xylene conversion rate (%) was calculated as follows: p-xylene conversion rate (%) = (5000 - p-xylene concentration at the outlet (unit: mg / m³)). 3 )) / 5000. This corresponds to the temperature (T) at which the p-xylene conversion reaches 99%. 99 To evaluate the catalytic performance of catalyst samples. 99 The lower the value, the higher the catalytic performance of the catalyst sample.

[0081] Sulfur resistance: The catalytic performance test was repeated, except that the p-xylene solvent was replaced with a mixture of p-xylene and dimethyl sulfide at a volume ratio of 9:1. The temperature (T') corresponding to a conversion rate of 99% for the mixture was then determined. 99 The sulfur resistance of the catalyst samples was evaluated using this method. 99 The lower the value, the higher the sulfur resistance of the catalyst sample.

[0082] Compressive strength: The front and side compressive strength of the catalyst samples were tested according to standard GB / T 5072-2008.

[0083] As described above, the performance of the catalysts in the examples and comparative examples was evaluated. The results are shown in Table 1.

[0084] Table 1

[0085]

Claims

1. A honeycomb catalyst containing a spinel-type non-noble metal oxide, comprising (1) a fibrous silicate clay, (2) an AB2O4 spinel-type oxide, and (3) a lanthanum- or cerium-containing rare earth mineral, wherein the fibrous silicate clay comprises at least one of attapulgite, halloysite, wollastonite, or sepiolite, wherein A and B are different non-noble metals and each is independently selected from at least one of nickel, cobalt, iron, manganese, titanium, or copper, and wherein the lanthanum- or cerium-containing rare earth mineral comprises at least one of bastnasite, parisite, or synchysite, and wherein the honeycomb catalyst is prepared by a method comprising the steps of: (1) providing an organic acid-modified fibrous silicate clay comprising the steps of: applying an isocyanate silane coupling agent and an organic acid to the fibrous silicate clay; (2) mixing the organic acid-modified fibrous silicate clay, water, a water-soluble salt of A, and a water-soluble salt of B, and drying the mixture to obtain a xerogel-like composite; (3) mixing the xerogel-like composite of step (2), the lanthanum- or cerium-containing rare earth mineral, and an extrusion aid, and molding, drying, and calcining the mixture to obtain the honeycomb catalyst.

2. The honeycomb catalyst of claim 1, wherein the mass ratio of the AB2O4 spinel-type oxide to the fibrous silicate clay is 0.08-0.30: 1, and the mass ratio of the total amount of the AB2O4 spinel-type oxide and the fibrous silicate clay to the lanthanum- or cerium-containing rare earth mineral is 0.5-2.0:

1. wherein (1) a fibrous silicate clay, (2) an AB2O4 spinel-type oxide, and (3) a lanthanum- or cerium-containing rare earth mineral.

4. A method of preparing the honeycomb catalyst of any one of claims 1-3, comprising the steps of: (1) providing an organic acid-modified fibrous silicate clay comprising the steps of: applying an isocyanate silane coupling agent and an organic acid to the fibrous silicate clay; (2) mixing the organic acid-modified fibrous silicate clay, water, a water-soluble salt of A, and a water-soluble salt of B, and drying the mixture to obtain a xerogel-like composite; (3) mixing the xerogel-like composite of step (2), the lanthanum- or cerium-containing rare earth mineral, and an extrusion aid, and molding, drying, and calcining the mixture to obtain the honeycomb catalyst. The providing of the organic acid-modified fibrous silicate clay in step (1) comprises the steps of: applying the isocyanate silane coupling agent to the fibrous silicate clay, wherein the mass ratio of the isocyanate silane coupling agent to the fibrous silicate clay is 0.05-0.15: 1; and applying the organic acid to the fibrous silicate clay, wherein the mass ratio of the organic acid to the fibrous silicate clay is 0.05-0.2:

1.

6. The method of claim 5, wherein the isocyanate silane coupling agent is at least one of 3-isocyanatopropyltrimethoxysilane or 4-isocyanatopropyltriethoxysilane, and the organic acid is one of citric acid or tartaric acid. ​ 3. The honeycomb catalyst of claim 1 consisting of: ​ ​ ​ ​ ​ 5. The method of claim 4, wherein, ​ ​ 7. The method of claim 4, wherein, The mixing of the organic acid-modified fibrous silicate clay, water, the water-soluble salt of A, and the water-soluble salt of B in step (2) includes the steps of: dispersing the organic acid-modified fibrous silicate clay in water, wherein the mass ratio of the organic acid-modified fibrous silicate clay to water is 0.05-0.2:1; and adding the water-soluble salt of A and the water-soluble salt of B in an amount such that the mass ratio of the AB2O4 spinel-type oxide to the fibrous silicate clay in the honeycomb catalyst obtained is 0.08-0.30:

1.

8. The method of claim 4, wherein, In step (2), the mixture is evaporated to dryness at 85-95°C, dried at 110-140°C for 1-3 hours, and pulverized to obtain a xerogel-like composite, wherein the xerogel-like composite contains an AB2O4 spinel-type oxide precursor and a fibrous silicate clay.

9. The method of claim 7, wherein, The water-soluble salt of A is at least one of a nitrate, a chloride, a sulfate, or an acetate of A, and the water-soluble salt of B is at least one of a nitrate, a chloride, a sulfate, or an acetate of B.

10. The method of claim 4, wherein, The mixing of the xerogel-like composite of step (2), the lanthanum- or cerium-containing rare earth mineral, and the extrusion aid in step (3) includes the steps of: kneading the xerogel-like composite of step (2), the lanthanum- or cerium-containing rare earth mineral, and an aqueous solution of glycerol for 30-90 minutes, wherein the mass ratio of the xerogel-like composite to the lanthanum- or cerium-containing rare earth mineral is 0.5-2.0:1 and the mass ratio of glycerol to the xerogel-like composite is 0.05-0.1:1; and pugging the mixture 4-6 times.

11. The method of claim 4, wherein, In step (3), the mixture is shaped from an extruder, dried at 90-120°C for 30-60 minutes, and calcined at 550-750°C for 2-8 hours to obtain the honeycomb catalyst.

12. Use of the honeycomb catalyst of any one of claims 1-3 in the degradation of volatile organic compounds.

13. The use of claim 12, wherein the degradation of volatile organic compounds comprises: The honeycomb catalyst is charged in a reactor, and a gas containing a volatile organic compound is supplied to the reactor at a gas space velocity of 4000 to 25000 h"1 and a temperature of 150 to 550°C to remove the volatile organic compound from the gas. -1 and a temperature of 150 to 550°C to remove the volatile organic compound from the gas.

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