A copper-chromium-zirconium alloy catalyst, its preparation and use in the catalytic oxidation of hcl

Abstract

This invention belongs to the field of catalytic oxidation of HCl, specifically relating to a copper-chromium-zirconium alloy catalyst, comprising copper-chromium-zirconium alloy particles and CeO2. This invention also includes the preparation of the catalyst and its application in the catalytic oxidation of HCl. In this invention, the catalyst can synergistically improve the catalytic activity of HCl, particularly addressing the problem of carbon deposition in HCl catalysts containing organic impurities.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to the field of HCl catalytic oxidation to produce chlorine. Background Technology

[0002] During the high-temperature chlorination of propylene to produce allyl chloride, in addition to the reaction of propylene with chlorine to produce allyl chloride, a large amount of hydrogen chloride is also produced as a byproduct. This hydrogen chloride, along with excess propylene and other impurities, is discharged as a mixed tail gas. The separated hydrogen chloride contains organic impurities such as propylene, significantly increasing the difficulty of subsequent utilization. Currently, there is a lack of effective methods in China for treating this impure hydrogen chloride; most processes involve water absorption to produce hydrochloric acid, followed by alkali neutralization to form salt. This process is costly and generates secondary pollutants. For a long time, the treatment of byproduct hydrogen chloride has been a common problem in industries such as epoxy resins, making the search for more economical and environmentally friendly solutions to the utilization of byproduct hydrogen chloride urgent.

[0003] According to literature, the oxidation of hydrogen chloride with hydrogen chloride to produce chlorine is an effective way to achieve closed-loop utilization of chlorine resources. However, existing catalytic systems are designed for pure hydrogen chloride, and catalysts for impure hydrogen chloride containing organic impurities such as propylene have not been reported. Compared to pure hydrogen chloride gas, the oxidation reaction of hydrogen chloride containing organic impurities places higher demands on the catalyst, and two main technical problems need to be overcome: 1) In an oxygen-rich system, organic impurities, especially reactive compounds such as propylene, are easily adsorbed on the catalyst surface and undergo polymerization reactions under the strongly acidic conditions of hydrogen chloride. The resulting polymerization products gradually carbonize and accumulate under high-temperature reaction conditions, leading to a decrease in catalyst activity or even deactivation; 2) Local heat accumulation is likely to occur, causing loss of active components and uneven temperature distribution in the catalyst bulk, resulting in breakage, pulverization, and even blockage of pipelines, affecting the safe operation of the equipment. These two problems are interconnected and mutually restrictive. When catalyst activity decreases, it is usually necessary to increase the reaction temperature to maintain activity, but the corresponding carbon deposition and heat accumulation accelerate the pulverization and breakage of the catalyst. Therefore, developing catalysts for hydrogen chloride gas containing organic impurities in the high-temperature, oxygen-rich hydrogen chloride reaction has significant application value. Summary of the Invention

[0004] To address the problems of unsatisfactory catalytic activity and stability caused by carbon buildup and localized heat accumulation in the catalytic oxidation of hydrogen chloride containing organic impurities, the primary objective of this invention is to provide a copper-chromium-zirconium alloy catalyst. This catalyst is suitable for the catalytic oxidation of hydrogen chloride containing organic impurities, effectively reduces carbon buildup and abnormal localized heat accumulation, and possesses excellent catalytic activity and stability.

[0005] The second objective of this invention is to provide a method for preparing the copper-chromium-zirconium alloy catalyst and its application in the catalytic oxidation of hydrogen chloride, particularly hydrogen chloride containing organic impurities.

[0006] A copper-chromium-zirconium alloy catalyst comprising copper-chromium-zirconium alloy particles and CeO2.

[0007] This invention has found that the combination of copper-chromium-zirconium alloy particles and CeO2 can achieve synergy, effectively resist carbon deposition problems, effectively reduce the heat released by the reaction, and reduce the local abnormal accumulation of heat. This can effectively improve catalytic activity and catalytic stability, especially effectively improve the selectivity, activity and stability of catalytic oxidation of hydrogen chloride containing organic impurities.

[0008] In this invention, the copper-chromium-zirconium alloy particles are tightly bonded together by CeO2.

[0009] In this invention, the combination of the special copper-chromium-zirconium alloy composition and the CeO2 binder composition helps to further achieve synergy in composition and structure, and helps to further solve the problems of carbon deposition and local heat accumulation, and is key to improving the catalytic activity and stability of hydrogen chloride, especially hydrogen chloride containing organic impurities.

[0010] In this invention, the mass ratio of Cu:Cr:Zr in the copper-chromium-zirconium alloy particles is 12-16:12-16:1-2.

[0011] Preferably, the method further includes auxiliary components, which include inorganic binders and / or silicon carbide; the auxiliary components include at least one of Al2O3, TiO2, CeO2, SiO2, clay, borate, and silicate.

[0012] This invention also found that adding auxiliary components to the catalyst can further improve the synergy of catalytic components, help solve the problems of carbon deposition and local heat accumulation, and improve the catalytic activity and stability of hydrogen chloride, especially hydrogen chloride containing organic impurities.

[0013] Preferably, the auxiliary components include silicon carbide; more preferably, the auxiliary components include silicon carbide and an inorganic binder.

[0014] Preferably, in the copper-chromium-zirconium alloy catalyst, the copper-chromium-zirconium alloy particles are dispersed in a binder matrix, which includes the CeO2 and auxiliary components. In this invention, the combination of the aforementioned components and the special binder structure helps to synergistically solve the problems of carbon deposition and localized heat accumulation, and improve the catalytic activity and stability of hydrogen chloride, especially hydrogen chloride containing organic impurities.

[0015] In the copper-chromium-zirconium alloy catalyst, the total content of copper-chromium-zirconium alloy particles and CeO2 is 10-50 wt.%; wherein the weight ratio of copper-chromium-zirconium alloy particles to CeO2 is 2-10:1.

[0016] Preferably, in the copper-chromium-zirconium alloy catalyst, the total content of copper-chromium-zirconium alloy particles and CeO2 is 12-30 wt.%, wherein the weight ratio of copper-chromium-zirconium alloy particles to CeO2 is 3-7.5:1.

[0017] The present invention also provides a method for preparing the copper-chromium-zirconium alloy catalyst, wherein copper-chromium-zirconium alloy particles, CeO2 and its precursor raw materials are mixed, shaped and calcined to obtain the catalyst.

[0018] In this invention, the copper-chromium-zirconium alloy particles can be prepared using existing methods, such as vacuum melting, ultrasonic atomization, and sieving of Cu, Cr, and Zr ingots.

[0019] Preferably, the smelting parameters are: vacuum degree <8×10 -2 Pa, purged with argon gas to a pressure of 0.05-0.08 MPa, and smelted at a temperature of 1750-1800℃;

[0020] Preferably, the copper-chromium-zirconium alloy particles are calcined before being mixed with other components;

[0021] Preferably, the calcination temperature is 1000–1400℃, and the calcination time is 10–48 h.

[0022] In this invention, the precursor of CeO2 is a raw material that can be converted into CeO2, preferably at least one of cerium carbonate, cerium nitrate, and cerium organic acid;

[0023] Preferably, the raw materials for preparation also include auxiliary raw materials, which include at least one of silicon carbide, inorganic binder raw materials, and lubricant;

[0024] The inorganic binder raw material is an inorganic binder and its precursor raw material, preferably at least one of boehmite, titanium sol, silica sol, silicate, clay, and borate;

[0025] Preferably, the lubricant is at least one of guar gum powder, citric acid, graphite, polyethylene glycol, vinyl alcohol, and glycerin.

[0026] Preferably, the raw materials include copper-chromium-zirconium alloy particles, CeO2, silicon carbide, boehmite, guar gum powder, and citric acid; preferably, the weight ratio of the total weight of copper-chromium-zirconium alloy particles and CeO2, silicon carbide, boehmite, guar gum powder, and citric acid is 15:10-20:60-80:0.5-2:0.5-2.

[0027] In this invention, the atmosphere during the calcination process is an oxygen-containing atmosphere, such as oxygen, air, an oxygen-nitrogen mixture, or an oxygen-inert gas mixture.

[0028] Preferably, the roasting temperature is 400–800°C, and more preferably 450–600°C;

[0029] Preferably, the roasting time is 6 to 12 hours, and more preferably 9 to 11 hours.

[0030] A preferred method for preparing a catalyst according to the present invention includes the following steps:

[0031] S1: Ingots of Cu, Cr, and Zr are placed in a vacuum melting furnace and melted. After the melt is cleared, the temperature is maintained for 1–5 minutes to obtain a liquid alloy. The melting parameters are: vacuum degree <8 × 10⁻⁶. -2 Pa, purged with argon gas to a pressure of 0.05–0.08 MPa, and smelted at a temperature of 1750–1800 °C;

[0032] S2: The alloy liquid is added to an ultrasonic atomizer and atomized to obtain powder, which is then sieved to obtain alloy powder; the sieving is through a 50-200 mesh sieve, preferably a 100 mesh sieve; the atomization frequency is 50-350kHz, the atomization time is 2-10min, and argon gas is continuously introduced into the atomizer during the atomization process.

[0033] S3: Calcine the alloy powder at 1000-1400℃ for 10-48h, and then cool it naturally to room temperature before mixing it thoroughly with CeO2 powder; the CeO2 powder can pass through a 50-200 mesh sieve, preferably a 100 mesh sieve.

[0034] S4: The above-mentioned mixed powder is mixed with silicon carbide powder, pseudoboehmite, guar gum powder and citric acid, and then extruded into strips. After post-treatment, a copper-chromium-zirconium alloy catalyst doped with CeO2 is obtained.

[0035] The post-processing includes: drying the formed catalyst, treating it under high-temperature air conditions for a period of time, and naturally cooling it to room temperature to obtain a CeO2-doped copper-chromium-zirconium alloy catalyst; the drying temperature is 100-140℃, preferably 120℃; the drying time is 5-12h, preferably 10h; the high-temperature air treatment temperature is 400-800℃, preferably 400-600℃, more preferably 500℃; the high-temperature air treatment time is 6-12h, preferably 10h.

[0036] The present invention also provides an application of the copper-chromium-zirconium alloy catalyst described above, using it as a catalyst for the catalytic oxidation of hydrogen chlorination to produce chlorine gas.

[0037] In a preferred application, this invention is used as a catalyst for the production of chlorine from hydrogen chloride containing organic impurities. The catalyst described in this invention exhibits excellent catalytic selectivity for hydrogen chloride containing organic impurities, which presents greater processing challenges, and effectively resists carbon buildup and localized heat accumulation, demonstrating excellent catalytic activity and stability.

[0038] Preferably, the organic impurities include: C 2-6 Alkanes, C 2-6 Olefins, C 2-6 Alkynes, C 2-6 Alcohols, 3-6 membered epoxides, C 2-6 One or more of chlorinated organic compounds;

[0039] For example, the organic impurities include 0.5-2% propylene, 0.01-0.5% ethylene oxide, 0.1-0.4% 2-chloroethanol by volume, and at least one of ethylene, ethane, dichloroethane, acetylene, 2-chloroethanol, 1,2-dichloroethane, cyclopropane, propyne, propadiene, propane, isobutane, n-butane, n-butene, 1,3-butadiene, cis-butene, chlorodiethylene glycol, diethylene glycol, and 1,4-dioxane by volume.

[0040] Preferably, the volume fraction of the organic impurities is 0.01% to 15%.

[0041] In this invention, the oxidation reaction temperature is 340–450°C, preferably 350–400°C, and more preferably 360–390°C;

[0042] The flow rate ratio of hydrogen chloride to O2 is 4.0:1.0 to 1.0:4.0.

[0043] In this invention, the method for preparing chlorine gas by catalytic hydrogen chlorination using a copper-chromium-zirconium alloy catalyst includes:

[0044] S1: Place the copper-chromium-zirconium alloy catalyst in the reactor, purge the air in the reactor with N2, raise the temperature to 350-400℃, and keep the temperature stable for a period of time;

[0045] S2: Introduce the hydrogen chloride gas to be treated, and after it has stabilized for a period of time, introduce oxygen to carry out the reaction;

[0046] Preferably, in step S1, the N2 purging flow rate is 50–200 ml / min; more preferably 100 ml / min; and the purging time is 2–8 h, more preferably 5 h.

[0047] Alternatively, in step S1, the heating rate is 5-15°C / min, preferably 10°C / min;

[0048] Alternatively, in step S1, the stabilization time is 0.5 to 2 hours, preferably 1 hour;

[0049] Alternatively, in step S2, the stabilization time is 3 to 8 hours, preferably 5 hours;

[0050] Alternatively, in step S2, the ratio of the rate of hydrogen chloride gas to the rate of oxygen introduction is 1 to 3:1; preferably, the ratio is 2:1.

[0051] Alternatively, the method for preparing chlorine gas by chlorination and oxidation may further include a chlorine gas collection step;

[0052] Preferably, the chlorine gas is collected by connecting a cold trap at the reactor outlet to collect water; the preferred temperature of the cold trap is 0°C.

[0053] The application described in this invention also includes a decarbonization and regeneration step for the copper-chromium-zirconium alloy catalyst:

[0054] The catalyst with carbon deposits after the reaction is placed in a tube furnace and heated to 350-650°C, and calcined in pure oxygen to remove carbon.

[0055] Preferably, the heating rate is 5-15°C / min, more preferably 10°C / min;

[0056] Preferably, the flow rate of the pure oxygen is 50–200 ml / min; more preferably, it is 100 ml / min.

[0057] Preferably, the calcination time is 3 to 10 hours, and more preferably 5 hours.

[0058] Beneficial effects

[0059] This invention provides a novel catalyst comprising copper-chromium-zirconium alloy particles and a binder matrix binding the copper-chromium-zirconium alloy particles together, wherein the binder matrix comprises CeO2 and silicon carbide. The novel material of this invention effectively solves the problems of carbon deposition, localized heat accumulation, powdering, or breakage that exist in the catalytic oxidation of hydrogen chloride containing organic impurities, and can effectively improve the catalytic activity, catalytic selectivity, and stability of hydrogen chloride containing organic impurities. Attached Figure Description

[0060] Figure 1 The results of the optimal catalytic temperature test for catalyst in Example 1;

[0061] Figure 2 The XRD patterns of the catalyst before and after use in Experiment Example 2 are shown. Detailed Implementation

[0062] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods or product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0064] the term:

[0065] “C 2-6 "Alkanes" refers to straight-chain or branched alkanes containing 2-6 carbons, such as ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, isohexane, 2,2-dimethylbutane, 2-methylpentane, 2,3-dimethylbutane, and 3-methylpentane, with ethane being a preferred example.

[0066] “C 2-6 "Olefins" refers to straight-chain or branched olefins containing 2-6 carbons and 1-3 double bonds, such as ethylene, propylene, 1-butene, male-butene, 2-methyl-1-propene, 1-pentene, 2-pentene, 3-pentene, 1,3-butadiene, etc., with ethylene and propylene being preferred examples.

[0067] “C 2-6 "Alkyne" refers to straight-chain or branched alkynes containing 2-6 carbons and 1-3 triple bonds, such as acetylene, propyne, 1-butyne, 2-butyne, 1-pentyne, 2-pentyne, 3-methyl-1-butyne, etc., with preferred examples being acetylene, propyne, 1-butyne, and 2-butyne.

[0068] “C 2-6 "Alcohol" refers to a compound in which 1-6 hydrogen atoms in an aliphatic hydrocarbon or alicyclic hydrocarbon containing 2-6 carbon atoms are replaced by hydroxyl groups. Examples include ethanol, propanol, butanol, pentanol, hexanol, ethylene glycol, glycerol, propylene glycol, diethylene glycol, pentaerythritol, allyl alcohol, and vinyl alcohol. Preferred examples include ethanol, propanol, ethylene glycol, propylene glycol, and diethylene glycol.

[0069] "3-6 membered epoxides" refer to cyclic compounds with 3-6 ring atoms and 1-3 oxygen atoms on the ring, such as ethylene oxide, propylene oxide, butane oxide, and 1,4-dioxane.

[0070] “C 2-6"Chlorinated organic compounds" refer to straight-chain aliphatic compounds (including saturated and unsaturated aliphatic hydrocarbons), aromatic compounds (such as chlorobenzene, chloronaphthalene, etc.), and cyclic compounds other than benzene, containing 2-6 carbon atoms and 1-6 hydrogen atoms replaced by chlorine atoms. Examples include dichloroethane, 2-chloroethanol, 1,2-dichloroethane, and chlorodiethylene glycol.

[0071] In this invention, the purity of the alloy raw materials—copper, chromium, zirconium, and cerium dioxide (CeO2)—is ≥99.9%.

[0072] Unless otherwise stated, the alloy particles in this invention are prepared according to the following method:

[0073] Cu, Cr, and Zr ingots were placed in a vacuum melting furnace and melted. After the melt was cleared, the temperature was maintained for 1–5 minutes to obtain a liquid alloy. The melting parameters were: vacuum degree <8 × 10⁻⁶. -2 Pa, purged with argon gas to a pressure of 0.05-0.08 MPa, and smelted at a temperature of 1750-1800℃;

[0074] The alloy liquid was added to an ultrasonic atomizer and atomized at a frequency of 200 kHz for 5 min. Argon gas was continuously introduced into the atomizer during the atomization process. The powder obtained by atomization was passed through a 100-mesh sieve to obtain CuCrZr alloy powder.

[0075] The comparison of the alloy particle composition is the same as above, the only difference being the change in the type and content of the elements.

[0076] Example 1: Preparation of CeO2-doped copper-chromium-zirconium alloy catalyst

[0077] Step (1): Calcine the alloy powder (CuCrZr alloy powder: where the weight ratio of Cu, Cr and Zr is 70:70:6) at 1200℃ for 20h, and after naturally cooling to room temperature, mix it thoroughly with CeO2 powder (100 mesh) to obtain a mixed powder, where the weight ratio of alloy powder to CeO2 powder is 146:20.

[0078] Step (2): 15g of the above mixed powder was thoroughly mixed with 15g of silicon carbide powder (2000 mesh), 75g of boehmite, 1g of guar gum powder and 1g of citric acid, and then extruded into strips (Φ: 3mm×10mm). The strips were dried at 120℃ for 10h and then treated in air at 500℃ for 10h. After naturally cooling to room temperature, the molded sample was obtained and labeled as CAT-1.

[0079] Example 2: Preparation of CeO2-doped copper-chromium-zirconium alloy catalyst

[0080] The method of Example 1 is different in that the weight ratio of Cu, Cr and Zr in the alloy powder is 60:60:8; in step (2), the weight ratio of alloy powder and CeO2 powder in the mixed powder is 128:40, and the rest is the same as in Example 1, and a catalyst is obtained, labeled as CAT-2.

[0081] Example 3: Preparation of CeO2-doped copper-chromium-zirconium alloy catalyst

[0082] The method of Example 1 is the same as in Example 1, except that in step (2), the mixed powder is 39.0g, and the rest is the same as in Example 1, to obtain a catalyst labeled CAT-3.

[0083] Example 4: Preparation of CeO2-doped copper-chromium-zirconium alloy catalyst

[0084] The method of Example 1 is the same as in Example 1, except that boehmite is not used in step (2). The catalyst is labeled CAT-4.

[0085] Example 5: Preparation of CeO2-doped copper-chromium-zirconium alloy catalyst

[0086] The method of Example 1 is the same as in Example 1, except that silicon carbide powder is not used in step (2). The catalyst is labeled CAT-5.

[0087] Comparative Example 1: Preparation of Copper-Based Catalyst

[0088] The method of Example 1 is the same as in Example 1, except that step (1) is omitted and a single copper powder is used to replace the mixed powder. The catalyst is labeled CAT-Cu.

[0089] Comparative Example 2: Preparation of Copper Chromium Zirconium Alloy Catalyst

[0090] The method of Example 1 is different in that: in step (2), the mixed powder contains only CuCrZr alloy powder and no CeO2 powder is added, and the weight of CuCrZr alloy powder is 15g. The rest is the same as in Example 1, and the catalyst is labeled as CAT-CuCrZr.

[0091] Comparative Example 3: Preparation of CeO2-doped copper-based catalysts

[0092] The method of Example 1 is the same, except that in step (1), a single copper powder is used to replace the alloy powder, and the amount of copper powder used is the same as that of the alloy powder. The rest is the same as in Example 1, and the resulting catalyst is labeled CAT-Cu-CeO2.

[0093] Comparative Example 4: Preparation of Copper Oxide and Chromium Oxide Catalysts

[0094] Weigh out 6.6g of copper oxide powder (100 mesh), 8.4g of chromium oxide powder (100 mesh), 15g of silicon carbide powder (2000 mesh), 75g of boehmite, 1g of guar gum powder, and 1g of citric acid. Mix thoroughly and extrude into strips (Φ: 3mm × 10mm), then dry at 120℃ for 10h. The resulting molded sample is labeled CAT-CuO / Cr2O3.

[0095] Comparative Example 5

[0096] The method of Example 1 is different in that: in step (1), iron powder is used to replace the copper component, and the rest is the same as in Example 1, and the catalyst is labeled as CAT-FeCrZr.

[0097] Experimental Example 1: Optimal Catalytic Temperature Test

[0098] In a quartz reactor with an inner diameter of 3.0 cm and a length of 40.0 cm, 20 ml of each of the following compounds were measured using a graduated cylinder: CAT-1, CAT-2, CAT-Cu, CAT-CuCrZr, CAT-Cu-CeO2, and CAT-CuO / Cr2O3. The reactor was then purged with N2 at a flow rate of 100 ml / min for 5 hours. The temperature was then increased to the catalytic temperature (280℃, 300℃, 320℃, 340℃, 360℃, 380℃, 450℃, 500℃) at a rate of 10℃ / min. A hydrogen chloride gas containing organic impurities (volume ratio of 1% propylene, 0.1% ethylene oxide, 0.2% 2-chloroethanol, and ≤1% C2-C6 alkanes, isoolefins, dienes, and alkynes) was introduced at a flow rate of 200 ml / min and stabilized for 5 h. Then, oxygen was introduced at a flow rate of 100 ml / min. Water was collected in a glass cold trap (0°C) connected to the reactor outlet. Chlorine gas was replaced with potassium iodide and then titrated with potassium thiosulfate. The remaining unreacted hydrogen chloride gas was titrated using acid-base neutralization to determine the hydrogen chloride conversion rate. Results are shown below. Figure 1 .

[0099] from Figure 1It can be seen that the control catalysts CAT-Cu, CAT-CuCrZr, and CAT-Cu-CeO2 all exhibit low catalytic efficiency in the 280-500℃ range. Within this temperature range, the optimal catalytic temperature for the control catalysts is above 450℃, resulting in significant energy loss. Furthermore, the reaction of hydrogen chloride oxidation to chlorine is exothermic, and high temperatures are not conducive to improving the hydrogen chloride conversion rate. In contrast, the CeO2-doped copper-chromium-zirconium alloy catalysts CAT-1 and CAT-2 achieve hydrogen chloride conversion rates exceeding 80% in the 340-450℃ range. At 500℃, the hydrogen chloride conversion rate actually decreases, indicating that the 340-450℃ temperature range can be considered the optimal operating temperature for the catalysts. Considering energy consumption, 340-390℃ can be considered the optimal catalytic temperature. This demonstrates that the simultaneous doping of Cr, Zr, and CeO2 lowers the catalytic reaction temperature while maintaining a high hydrogen chloride conversion rate.

[0100] Experimental Example 2: Catalytic Cycle Experiment

[0101] The reaction was carried out under the conditions of Experiment Example 1, with the catalytic temperature set at 340℃. After 200 hours, the reaction was stopped, the catalyst was removed, and placed in a tube furnace. The temperature was increased to 340℃ at a rate of 10℃ / min, and the catalyst was calcined in pure oxygen at a flow rate of 100 ml / min for 5 hours to remove carbon. The amount of carbon deposit was determined based on the change in catalyst weight. After decarbonization, the reaction was continued according to step 1, and a second decarbonization treatment was performed after 200 hours as described above. A total of 6 decarbonization cycles were conducted. The experimental results are shown in Table 1, and the XRD patterns of CAT-1 before and after use are also compared. Figure 2 .

[0102] Table 1. Catalyst Cyclic Performance Results

[0103]

[0104]

[0105]

[0106] As shown in Table 2, the metal oxide catalyst CAT-CuO / Cr2O3 exhibited slight pulverization after four decarbonization cycles, and significant pulverization and breakage occurred after six decarbonization cycles. This is likely due to the poor thermal conductivity of the metal oxide, making it difficult to conduct the heat generated at the catalyst's active sites in a timely manner. Excessive temperature differences between the bulk phases led to pulverization and breakage. This problem is significantly improved in catalysts based on copper or alloys.

[0107] The comparison of XRD spectra before and after catalyst use revealed that the bulk phase characteristics of the CeO2-doped copper-chromium-zirconium alloy remained intact and unchanged before and after use. This indicates that the alloy catalyst has stable performance and, while reducing the reaction temperature, also provides excellent heat transfer, heat dissipation, and anti-carbon deposition properties.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A copper-chromium-zirconium alloy catalyst, characterized in that, It includes copper-chromium-zirconium alloy particles, CeO2, and auxiliary components, wherein the auxiliary components include silicon carbide and inorganic binders.

2. The copper-chromium-zirconium alloy catalyst as described in claim 1, characterized in that, The copper-chromium-zirconium alloy particles are tightly bonded together by CeO2.

3. The copper-chromium-zirconium alloy catalyst as described in claim 2, characterized in that, In copper-chromium-zirconium alloy particles, the mass ratio of Cu:Cr:Zr is 12~16:12~16:1~2.

4. The copper-chromium-zirconium alloy catalyst as described in claim 1, characterized in that, In the copper-chromium-zirconium alloy catalyst, the copper-chromium-zirconium alloy particles are dispersed in a binder matrix, which includes CeO2 and auxiliary components.

5. The copper-chromium-zirconium alloy catalyst according to any one of claims 1 to 4, characterized in that, In the copper-chromium-zirconium alloy catalyst, the total content of copper-chromium-zirconium alloy particles and CeO2 is 10~50 wt.%; wherein the weight ratio of copper-chromium-zirconium alloy particles to CeO2 is 2~10:

1.

6. The copper-chromium-zirconium alloy catalyst as described in claim 5, characterized in that, In the copper-chromium-zirconium alloy catalyst, the total content of copper-chromium-zirconium alloy particles and CeO2 is 12~30 wt.%, wherein the weight ratio of copper-chromium-zirconium alloy particles to CeO2 is 3~7.5:

1.

7. A method for preparing the copper-chromium-zirconium alloy catalyst according to any one of claims 1 to 6, characterized in that, The copper-chromium-zirconium alloy particles, CeO2 and its precursor materials are mixed, shaped and calcined to obtain the product. The raw materials also include auxiliary ingredients, such as silicon carbide and inorganic binder. The inorganic binder raw materials are inorganic binders and their precursor raw materials.

8. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The copper-chromium-zirconium alloy particles are obtained by vacuum melting, ultrasonic atomization, and sieving of Cu, Cr, and Zr ingots. The smelting parameters are: vacuum degree <8×10 -2 Pa, purged with argon gas to a pressure of 0.05-0.08 MPa, and smelting temperature of 1750~1800℃; The copper-chromium-zirconium alloy particles are calcined and then mixed with other components; The calcination temperature is 1000~1400 o C, the calcination time is 10~48h.

9. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The precursor of CeO2 is a raw material that can be converted into CeO2.

10. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 9, characterized in that, The precursor of CeO2 is at least one of cerium carbonate, cerium nitrate, and cerium organic acid.

11. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The inorganic binder raw material is at least one of boehmite, titanium sol, silica sol, silicate, clay, and borate.

12. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The raw materials also contain a lubricant, which is at least one of guar gum powder, citric acid, graphite, polyethylene glycol, vinyl alcohol, and glycerin.

13. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The raw materials used in the preparation include copper-chromium-zirconium alloy particles, CeO2, silicon carbide, boehmite, guar gum powder, and citric acid.

14. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 13, characterized in that, The total weight of copper-chromium-zirconium alloy particles and CeO2, and the weight ratio of silicon carbide, pseudoboehmite, guar gum powder and citric acid are 15:10~20:60~80:0.5~2:0.5~2.

15. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 7, characterized in that, The roasting process is carried out in an oxygen-containing atmosphere.

16. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 15, characterized in that, The roasting temperature is 400~800℃.

17. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 16, characterized in that, The roasting temperature is 450~600℃.

18. The method for preparing the copper-chromium-zirconium alloy catalyst as described in claim 16, characterized in that, The roasting time is 6 to 12 hours.

19. The application of the copper-chromium-zirconium alloy catalyst according to any one of claims 1 to 6 or the copper-chromium-zirconium alloy catalyst prepared by any one of claims 7 to 18, characterized in that, It was used as a catalyst for the catalytic oxidation of hydrogen chlorination to produce chlorine gas.

20. The application as described in claim 19, characterized in that, It was used as a catalyst in the preparation of chlorine gas from the hydrogen chlorination process containing organic impurities.

21. The application as described in claim 20, characterized in that, The organic impurities include: C 2-6 Alkanes, C 2-6 Olefins, C 2-6 Alkynes, C 2-6 Alcohols, 3-6 membered epoxides, C 2-6 One or more of chlorinated organic compounds.

22. The application as described in claim 21, characterized in that, The organic impurities include 1% propylene, 0.1% ethylene oxide, 0.2% 2-chloroethanol, and ≤1% of at least one of ethylene, ethane, dichloroethane, acetylene, 2-chloroethanol, 1,2-dichloroethane, cyclopropane, propyne, propadiene, propane, isobutane, n-butane, n-butene, 1,3-butadiene, cis-butene, chlorodiethylene glycol, diethylene glycol, and 1,4-dioxane.

23. The application as described in claim 22, characterized in that, The volume fraction of the organic impurities is 0.01% to 15%.

24. The application as described in claim 19, characterized in that, The oxidation reaction takes place at a temperature of 340~450℃.

25. The application as described in claim 24, characterized in that, The oxidation reaction takes place at a temperature of 350~400℃.

26. The application as described in claim 25, characterized in that, The oxidation reaction takes place at a temperature of 360~390℃.

27. The application as described in claim 19, characterized in that, The flow rate ratio of hydrogen chloride to O2 is 4.0:1.0 to 1.0:4.

0.

28. The application as described in claim 19, characterized in that, Methods for producing chlorine gas by catalytic hydrogen chlorination using copper-chromium-zirconium alloy catalysts include: S1: Place the copper-chromium-zirconium alloy catalyst in the reactor, purge the air in the reactor with N2, raise the temperature to 350~400℃, and keep the temperature stable for a period of time; S2: Introduce the hydrogen chloride gas to be treated, and after it has stabilized for a period of time, introduce oxygen to carry out the reaction; In step S1, the flow rate of N2 purging is 50~200 ml / min; the purging time is 2~8 h; Alternatively, in step S1, the heating rate is 5~15℃ / min; Alternatively, in step S1, the stabilization time is 0.5~2h; Alternatively, in step S2, the stabilization time is 3~8 hours; Alternatively, in step S2, the ratio of the rate of hydrogen chloride gas to the rate of oxygen introduction is 1~3:1; Alternatively, the method for preparing chlorine gas by chlorination and oxidation may further include a chlorine gas collection step.

29. The application as described in claim 28, characterized in that, The method for collecting chlorine gas is to connect a cold trap at the reactor outlet to collect water; the temperature of the cold trap is 0°C.

30. The application according to any one of claims 19 to 29, characterized in that, It also includes a decarbonization and regeneration step for the copper-chromium-zirconium alloy catalyst.

31. The application according to claim 30, characterized in that, The regeneration step is as follows: the catalyst with carbon deposits after the reaction is placed into a tube furnace, heated to 350~650℃, and calcined in pure oxygen to remove carbon. The heating rate is 5~15℃ / min; The flow rate of the pure oxygen is 50~200 ml / min; The calcination time is 3 to 10 hours.

Images