Catalyst for hydrogen chloride catalytic oxidation to produce chlorine gas and preparation and application thereof

Abstract

The application belongs to the field of HCl catalytic oxidation, and particularly relates to a preparation method of a catalyst for preparing chlorine gas through HCl catalytic oxidation. A carrier is subjected to one-pot auxiliary co-impregnation treatment in a metal solution containing a copper source, a metal M source, a lanthanum source, a potassium source and an acid modifier, and then alkali is added to the system for co-precipitation to obtain a precursor. The precursor is calcined in an oxygen-containing atmosphere to obtain the catalyst. The acid modifier is R-COOH, R is H or an alkyl group with 1-4 carbon atoms, and the metal M element in the metal M source is manganese and / or cobalt. The application also includes the catalyst prepared by the preparation method and the application of the catalyst in HCl catalytic oxidation. In the application, the catalyst prepared by the process can improve the catalytic performance of HCl, especially the catalytic performance of HCl under low oxygen.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysts, and particularly relates to a method for HCl catalytic oxidation. BACKGROUND

[0002] Chlorine is an important chemical raw material, and the annual consumption of chlorine in China exceeds 20 million tons. More than 50% of the chlorine is used to produce polyvinyl chloride, polyurethane, polycarbonate and chlorofluorocarbons. In the chlorination reaction, there is a common problem of low utilization rate of chlorine atoms. One mole of chlorine is consumed to produce one mole of by-product hydrogen chloride. At present, the by-product hydrogen chloride is mostly absorbed by water to produce hydrochloric acid. With the increasing unsalability of hydrochloric acid and more stringent environmental protection requirements, how to convert hydrogen chloride into chlorine to realize recycling has become an important demand for the sustainable development of the chlorine industry.

[0003] The types of catalysts for hydrogen chloride catalytic oxidation method for producing chlorine include iron-based, copper-based, chromium-based, ruthenium-based and cerium-based catalysts. The ruthenium-based catalyst with rutile titanium dioxide as the carrier to load RuO2 is the only industrialized catalyst at present. Many patents such as US5871707, US2007292336 and EP2026905 of European Patent are all about the synthesis and application of ruthenium-based catalysts based on Japanese patent US5871707. The ruthenium-based catalyst has high activity and stability at a temperature below 400℃, but when the reaction temperature is higher than 400℃, volatile matter will be formed and then deactivated. Ruthenium is a noble metal, which is expensive and has great fluctuation, which seriously hinders its wide application. Therefore, the development of non-noble metal catalysts with high activity and stability is still the focus of the current research.

[0004] Among the non-noble metal types, copper-based catalysts are the focus of research at home and abroad. Chinese patents CN101862663A, CN102658149A, CN104923239A, CN105268448A, CN105289631A, CN105642318A, US5707919, and European patent WO2011104212A1 are about the application of copper-based catalysts in the catalytic oxidation of hydrogen chloride. However, the stability of copper-based catalysts is low, and alkali metals K and Na and rare earth metals La, Sm or Pr with high cost need to be added as additives to form high-boiling compounds to reduce their volatility. The copper catalysts reported in most of the above patents are operated under the condition that O2 / HCl is greater than 0.5, that is, under the condition of excessive oxygen. However, excessive oxygen increases the oxygen content in the subsequent product, thereby increasing the energy consumption of separation. Therefore, if the reaction can be carried out under the condition of as low oxygen as possible, especially under the condition of stoichiometric ratio (O2 / HCl = 0.25), the energy consumption of separation will be greatly reduced. However, a large number of studies have shown that under too low oxygen content, copper is difficult to quickly change from chlorinated state to oxidized state, thereby increasing the probability of volatile loss, and the catalyst is difficult to maintain long-term stability.

[0005] In summary, based on the analysis of existing hydrogen chloride oxidation catalysts, it can be seen that copper-based catalysts are a promising catalyst due to their high activity and good compatibility with additives. However, in order to reduce the energy consumption of the subsequent separation process of hydrogen chloride catalytic oxidation, the operation under low oxygen ratio puts higher requirements on the stability of the catalyst. Therefore, it is of important application value to optimize existing copper-based catalysts and develop new catalysts to meet the above requirements. SUMMARY

[0006] In view of the low stability of existing copper-based catalysts for hydrogen chloride catalytic oxidation to produce chlorine gas under low oxygen ratio conditions, the purpose of the present application is to provide a stable copper-based catalyst that can tolerate low oxygen ratio, aiming to improve its catalytic ability under low oxygen content.

[0007] The second object of the present application is to provide a catalyst preparation method and a method for HCl catalytic oxidation using the catalyst.

[0008] Existing HCl catalytic oxidation needs to be carried out under a large oxygen ratio, which increases the difficulty of separating Cl2 and O2 in the product; in view of this industry problem, the present application provides the following solutions:

[0009] A catalyst for hydrogen chloride catalytic oxidation to produce chlorine gas, which comprises a carrier and an active ingredient loaded thereon, the active ingredient comprising KCuCl3, CuLaO2, K2LaCl5 and active ingredient M:

[0010] The active ingredient M includes a Mn-based active ingredient and / or a Co-based active ingredient;

[0011] The Mn-based active ingredient includes at least one of KMnCl3, La8Mn8O 23 , CuMn2O4;

[0012] The Co-based active ingredient includes at least one of CuCoO2, CuCoO3, La2CoO4 and K2CoCl4.

[0013] The research of the present application shows that, due to the combination of the multi-phase active ingredients in the catalyst, the response efficiency of oxygen can be improved, the tolerance to hydrogen chloride can be improved; the catalytic oxidation effect of hydrogen chloride can be improved synergistically, especially the catalytic oxidation effect and stability of low-oxygen high-hydrogen chloride.

[0014] The Mn-based active ingredient includes at least one of KMnCl3, La8Mn8O 23 and CuMn2O4;

[0015] Preferably, the Co-based active ingredient includes CuCoO2, CuCoO3, La2CoO4 and K2CoCl4.

[0016] Preferably, the active ingredient M further contains at least one of CoMnO3 and MnCo2O4.

[0017] In the present application, the carrier is not particularly required, for example, the carrier is at least one of active alumina, silica, zirconia and titania.

[0018] In the present application, the content of the active ingredient can be adjusted according to the use requirement, for example, the content of the active ingredient is less than or equal to 40Wt%, preferably 5-30Wt%.

[0019] The present application also provides a preparation method of the catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine gas, which comprises the following steps: placing a carrier in a metal solution containing a copper source, a metal M source, a lanthanum source, a potassium source and an acid modifier for one-pot assisted co-impregnation treatment, then adding an alkali into the system for co-precipitation to obtain a precursor; and then calcining the precursor in an oxygen-containing atmosphere to obtain the catalyst.

[0020] The acid modifier is R-COOH, and R is H or C1-C4 alkyl.

[0021] The metal M element in the metal M source is manganese and / or cobalt.

[0022] The calcination temperature is 400-550 DEG C.

[0023] The present application research found that, on the basis of the innovative combination of the metal source, further assisted by the acid modifier, one-pot co-impregnation, co-precipitation, oxidation calcination and parameters, so that the special phase, the new catalyst of crystal face activity and micro-distribution can be obtained by calcination; more importantly, the catalyst prepared by the preparation method has excellent HCl catalytic oxidation effect, especially can improve the catalytic oxidation effect of HCl under low oxygen content.

[0024] In the present application, the element type and the auxiliary co-impregnation-co-precipitation combination are the key to obtain the new catalyst by calcination and improve the low oxygen catalytic activity.

[0025] In the present application, the one-pot co-impregnation assisted by the acid modifier is one of the keys to synergistically improve the catalytic performance of the catalyst, especially the low oxygen catalytic performance.

[0026] In the present application, the copper source, the metal M source, the lanthanum source and the potassium source are water-soluble salts of each metal, preferably at least one of chloride, sulfate, nitrate and organic acid salt; preferably chloride.

[0027] Preferably, the molar ratio of Cu, M, La and K in the copper source, the metal M source, the lanthanum source and the potassium source is 1:0.04-0.4:0.1-0.5:0.3-0.5; preferably 1:0.09-0.4:0.1-0.45:0.3-0.5.

[0028] Preferably, the molar ratio of the total amount of the copper source, the metal M source, the lanthanum source and the potassium source to the carrier is 1:1-5; further preferably 1:2-4.

[0029] In the present application, the concentration in the metal solution has no special requirement, considering the convenience of preparation, the total metal concentration can be 0.1-1M.

[0030] In the acid modifier, R is C2-C3 alkyl;

[0031] Preferably, the acid modifier comprises R1-COOH and R2-COOH; wherein R1 is methyl and R2 is propyl. The present application research found that the combined modifier can further synergistically improve the catalytic activity of the catalyst, especially the catalytic activity under low oxygen.

[0032] Preferably, in the acid modifier, the molar ratio of R1-COOH and R2-COOH is 1:0.5-1.5;

[0033] Preferably, the molar ratio of the acid modifier to the total metal is 1-10:1; further preferably 4-6:1.

[0034] In the present application, the temperature and time of the co-impregnation are not particularly limited, and in consideration of the convenience of the process operation, the temperature of the co-impregnation stage is 10-60°C, and the time is 5 minutes-24 hours, further for example, 3-8 hours;

[0035] Preferably, the base used in the co-precipitation stage is ammonia water.

[0036] Preferably, the pH of the co-precipitation process is 9-10.

[0037] Preferably, the treatment time of the co-precipitation stage is 4-8 hours.

[0038] In the present application, after the co-precipitation, the precursor can be prepared by solid-liquid separation or evaporation.

[0039] Preferably, the oxygen-containing atmosphere is at least one of pure oxygen, oxygen-nitrogen mixed gas, oxygen-inert gas mixed gas, and air.

[0040] Preferably, the calcination time is 0.5-6 hours, and further can be 3-5 hours.

[0041] The present application also provides a method for preparing chlorine by catalytic oxidation of hydrogen chloride, wherein the catalytic oxidation reaction of HCl and O2 is carried out under the catalyst described in the present application to prepare chlorine.

[0042] In the present application, the molar ratio of O2 / HCl is greater than or equal to the stoichiometric ratio, and is preferably 0.25-4, and further preferably greater than 0.25 and less than 0.5. In the present application, in consideration of the industrial preparation value, the molar ratio of O2 / HCl is preferably 0.26-0.4.

[0043] The catalyst described in the present application can realize effective catalytic oxidation under low oxygen content for the first time in the industry, which can effectively reduce the preparation cost and reduce the difficulty of subsequent separation of oxygen and chlorine. The method of the present application can fill the technical gap of low-oxygen catalysis in the industry and has great industrial practical value. In addition, the catalyst described in the present application can also be used under high oxygen content.

[0044] As a preference, the temperature of the catalytic oxidation reaction process is 320-450°C, and further preferably 370-400°C. It is found that under the preferred catalytic conditions, the catalytic activity and catalytic stability can be taken into account.

[0045] Preferably, the reaction pressure is 0.1-3.0 MPa, and further preferably 0.1-0.2 MPa.

[0046] As a preference, the reaction of hydrogen chloride catalytic oxidation to prepare chlorine is carried out in a fixed bed reactor, and the volume space velocity of hydrogen chloride is 200-2000 h-1 ; further preferably more suitably 400~1000h -1 .

[0047] Preferably, the hydrogen chloride catalytic oxidation reaction for preparing chlorine is carried out in a fixed bed reactor, and the catalytic conditions are as follows: the reaction temperature is 320~450 DEG C, more suitably 370~400 DEG C, the reaction pressure is 0.1~1.0 MPa, more suitably 0.1~0.2 MPa, the molar ratio of oxygen to hydrogen chloride is 0.5:1~0.15:1, more suitably 0.5:1~0.25:1, and the volume space velocity of hydrogen chloride is 200~20000h -1 , more suitably 400~1000h -1 .

[0048] The technical principle and advantages of the present application are as follows:

[0049] Regarding the reason why the copper-based catalyst has volatility in the hydrogen chloride catalytic oxidation reaction process, researchers have different views. Most people believe that copper chloride and cupric oxide have low boiling points, and thus are easy to volatilize at high temperatures. In order to reduce the volatility, the method of adding alkali metals K and Na is used to form a double salt; rare earth metals La and Sm are added to form a perovskite structure with copper; or CuAl2O4 crystal phase is formed by co-precipitation with aluminum salt to increase the boiling point. When the proportion of hydrogen chloride in the inlet gas increases (the proportion of oxygen decreases), any catalyst will show a decrease in stability. That is, a high oxygen atmosphere is the general understanding of researchers for maintaining the stability of the catalyst. Regarding the reason, most people believe that the re-oxidation ability of the copper-based catalyst is weak, and thus a high oxygen atmosphere is needed to quickly re-oxidize it. The lowest oxygen ratio reported so far is the copper lanthanum potassium (abbreviated as CuLaK / Al2O3) catalyst, and the molar ratio of oxygen to hydrogen chloride is 0.5:1, and lower is not reported. In addition, another reason for copper volatilization may be that the lattice parameters of copper chloride and copper oxide are different, and frequent mutual conversion and deep chlorination cause lattice expansion, resulting in lower stability.

[0050] In view of the problem that the catalytic activity of the existing catalyst, especially the low-oxygen catalytic activity, is not ideal, the present application uses the copper source, metal M source, lanthanum source and potassium source as raw materials, and adopts one-pot co-impregnation and co-precipitation treatment assisted by the acid modifier, so that a material with special phase and microstructure can be obtained by calcination, and the prepared material has excellent effect in HCl catalytic oxidation, especially can significantly improve the catalytic activity under low oxygen.

[0051] The preparation method of the present application can construct the material with the special advantage phase and morphology, which shows faster response to oxygen and stronger anti-interference ability to hydrogen chloride (such as Figures 1-3); thus, under the reaction atmosphere of low oxygen and high hydrogen chloride, good stability is shown. For example, the transition state of the pulse experiment of the manganese promoted catalyst is analyzed by XRD, and it is found that this is mainly due to the synergistic effect of the oxygen storage characteristics and the chlorine storage characteristics of the catalyst transition state Figure 4 ); the catalytic performance of the prepared material can be effectively improved, and the HCl catalytic activity under low oxygen is particularly improved.

[0052] The catalyst described in the present application shows good stability and the chlorine gas yield per unit time per unit catalyst (abbreviated as: chlorine gas STY) is maintained at more than 3.16 g Cl2 / (g cat ·h) under the test of the molar ratio of oxygen to hydrogen chloride of 0.26:1, the reaction temperature of 370-400℃, and 146 hours. Compared with the copper-based catalyst currently applied to the fixed bed reactor, the catalyst shows better stability and higher activity under the reaction condition of low oxygen content.

[0053] The catalyst of the present application does not contain heavy metal components and noble metals, and thus is non-toxic and low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 It is a mechanism research graph of the catalyst in Comparative Example 1;

[0055] Figure 2 It is a mechanism research graph of the catalyst in Comparative Example 2;

[0056] Figure 3 It is a mechanism research graph of the catalyst in Example 1;

[0057] Figure 4 It is an XRD graph of the transition state catalyst in Example 1

[0058] Figure 5 It is an XRD graph of the catalyst before and after reaction in Example 1; DETAILED DESCRIPTION

[0059] (I) Catalyst preparation case

[0060] Example 1

[0061] CuCl2·2H2O, MnCl2·4H2O, LaCl3 and KCl are dissolved in 10 mL water, and the total metal molar amount is 1.32 mmol, wherein Cu:Mn:La:K = 1:0.4:0.1:0.38, CH3COOH (acid modifier; n CH3COOH : n 总金属=5), ultrasonically dissolved for 5 min, Al2O3 (molar ratio to total metal of 2.95) was added, and co-impregnation was carried out at room temperature for 5 hours. Then, ammonia was slowly added dropwise to maintain the pH at 9, and the co-precipitation reaction was carried out for 5 hours. After filtration, the solid was dried in an oven at 110℃ for 12 hours and calcined at 450℃ in air atmosphere for 4 hours to obtain the catalyst CuMnLaK / Al2O3.

[0062] 2.5 g of the prepared CuMnLaK / Al2O3 catalyst was loaded into a fixed-bed reactor. Oxygen was then introduced into the reactor at a flow rate of 10 mL / min, and hydrogen chloride at a flow rate of 38 mL / min (O2 / HCl = 0.26), respectively. The reaction temperature was 370 °C, and the reaction pressure was 0.1 MPa. After 2 hours of reaction, the amount of chlorine gas (STY) was 2.07 g. Cl2 ·g cat -1 ·h -1 After 146 hours of reaction, the amount of chlorine gas (STY) was 2.07 g. Cl2 ·g cat -1 ·h -1 The catalyst activity remained unchanged.

[0063] XRD patterns of the catalyst in Example 1 before and after the reaction are shown below. Figure 5 .Depend on Figure 5 It can be seen that the number of crystallization peaks of the catalyst increased after the reaction, indicating that the crystal structure of the catalyst changed under the reaction atmosphere. By comparing with the standard peaks, it can be concluded that the copper, manganese, lanthanum, and potassium in the catalyst before the reaction exist in the forms of Cu2(OH)3Cl, MnCl2·2H2O, LaCl3·7H2O, and KCl, respectively; after complete reaction, the active components that play a catalytic role are KCuCl3, KMnCl3·2H2O, K2LaCl5, and La8Mn8O. 23 The presence of CuLaO2 and CuMn2O4 indicates that the active components are composed of multiple crystal phases.

[0064] Example 2

[0065] Compared with Example 1, the total molar amount of metal remained unchanged, the only difference being the molar ratio of the metal elements: Cu:Mn:La:K = 1:0.36:0.14:0.38. Other operations and parameters were the same as in Example 1, and measurements were performed according to the scheme of Example 1.

[0066] The catalyst prepared in this case produced 2.13g of chlorine gas (STY) after 2 hours of reaction. Cl2 ·g cat -1 ·h -1 After 146 hours of reaction, the amount of chlorine gas (STY) was 2.13g. Cl2 ·gcat -1 ·h -1 , the catalyst activity is unchanged.

[0067] Example 3

[0068] Compared with Example 1, the total metal molar amount is unchanged, the only difference is that the molar ratio of metal elements is Cu:Mn:La:K = 1:0.09:0.41:0.38. Other operations and parameters are the same as Example 1, and the determination is carried out according to the scheme of Example 1.

[0069] The catalyst prepared in this case has a chlorine STY of 2.95g Cl2 ·g cat -1 ·h -1 after 146 hours of reaction, the chlorine STY is 2.95g Cl2 ·g cat -1 ·h -1 , the catalyst activity is unchanged.

[0070] Comparative Example 1

[0071] Compared with Example 1, the only difference is that LaCl3 is absent, other operations and parameters are the same as Example 1, and the determination is carried out according to the scheme of Example 1.

[0072] The catalyst prepared in this case is marked as CuMnK / Al2O3; the chlorine STY after 2 hours of reaction is 1.31g Cl2 ·g cat -1 ·h -1 after 146 hours of reaction, the chlorine STY is 1.25g Cl2 ·g cat -1 ·h -1 , the catalyst activity is decreased.

[0073] Comparative Example 2

[0074] Compared with Example 1, the only difference is that MnCl2 is absent, other operations and parameters are the same as Example 1, and the determination is carried out according to the scheme of Example 1.

[0075] The catalyst prepared in this case is marked as CuLaK / Al2O3, and the chlorine STY after 2 hours of reaction is 1.85g Cl2 ·g cat -1 ·h -1 after 146 hours of reaction, the chlorine STY is 1.67g Cl2 ·g cat -1 ·h-1 The catalyst activity is decreased.

[0076] Comparative Example 3

[0077] Comparative Example 1 except that LaCl3and KCl are absent, and other operations and parameters are the same as in Example 1, and the determination is carried out according to the procedure of Example 1.

[0078] The catalyst prepared in this case is marked as CuMn / Al2O3; the chlorine STY after 2 hours of reaction is 1.28 g Cl2 ·g cat -1 ·h -1 The chlorine STY after 20 hours of reaction is 0.92 g Cl2 ·g cat -1 ·h -1 The catalyst activity is decreased.

[0079] Comparative Example 4

[0080] Comparative Example 1 except that MnCl2.4H2O and KCl are absent, and other operations and parameters are the same as in Example 1, and the determination is carried out according to the procedure of Example 1.

[0081] The catalyst prepared in this case is marked as CuLa / Al2O3. The chlorine STY after 2 hours of reaction is 1.52 g Cl2 ·g cat -1 ·h -1 The chlorine STY after 40 hours of reaction is 1.26 g Cl2 ·g cat -1 ·h -1 The catalyst activity is decreased.

[0082] Comparative Example 5

[0083] Comparative Example 1 except that equimolar amount of FeCl3is used to replace MnCl2.4H2O.

[0084] Other operations and parameters are the same as in Example 1, and the determination is carried out according to the procedure of Example 1.

[0085] The catalyst prepared in this case is marked as CuFeLaK / Al2O3; the chlorine STY after 2 hours of reaction is 1.95 g Cl2 ·g cat -1 ·h -1 The chlorine STY after 20 hours of reaction is 1.42 g Cl2 ·g cat -1 ·h-1 The catalyst activity is decreased obviously.

[0086] Comparative Example 6

[0087] Comparative Example 1 except that the molar ratio of metal elements is Cu:Mn:La:K = 1 :0.44:0.06:0.38. Other operations and parameters are the same as Example 1, and the determination is carried out according to the scheme of Example 1.

[0088] The catalyst prepared in this case is marked as CuNiLaK / Al203; the chlorine STY after 2 hours of reaction is 1.74 g Cl2 ·g cat -1 ·h -1 The chlorine STY after 146 hours of reaction is 1.74 g Cl2 ·g cat -1 ·h -1 The catalyst activity is decreased.

[0089] Comparative Example 7

[0090] Comparative Example 1 except that the molar ratio of metal elements is Cu:Mn:La:K = 1 :0.44:0.06:0.38. Other operations and parameters are the same as Example 1, and the determination is carried out according to the scheme of Example 1.

[0091] The catalyst prepared in this case is marked as CuNiLaK / Al203; the chlorine STY after 2 hours of reaction is 1.74 g Cl2 ·g cat -1 ·h -1 The chlorine STY after 146 hours of reaction is 1.74 g Cl2 ·g cat -1 ·h -1 The catalyst activity is unchanged.

[0092] Comparative Example 8

[0093] Comparative Example 1 except that some elements are separately impregnated and then mixed. The difference is as follows:

[0094] According to the metal source ratio and the acid modifier ratio of Example 1, a mixed solution of CuCl2·2H2O, LaCl3and KCl is impregnated into alumina for 5 hours, and the subsequent steps are the same as Example 1 to obtain solid A.

[0095] At the same time, according to the metal source ratio and the acid modifier ratio, a mixed solution of CuCl2·2H2O and MnCl2·4H2O is impregnated into alumina for 5 hours, and the subsequent steps are the same as Example 1 to obtain solid B.

[0096] A and B were mixed to prepare the catalyst of this study, and its composition was determined according to the procedure in Example 1. The chlorine STY after 2 hours of reaction was 1.72 g. Cl2 ·g cat -1 ·h -1 After 40 hours of reaction, the chlorine gas concentration (STY) was 1.25g. Cl2 ·g cat -1 ·h -1 The catalyst activity decreased significantly.

[0097] Comparative Example 9

[0098] Compared to Example 1, the only difference was that CH3COOH was not added; all other operations and parameters were the same as in Example 1, and measurements were performed according to the procedure in Example 1. The chlorine STY after 2 hours of reaction was 1.86 g. Cl2 ·g cat -1 ·h -1 .

[0099] Comparative Example 10

[0100] Compared to Example 1, the only difference is that CH3COOH was replaced with an equimolar amount of CH3COONH4. All other operations and parameters were the same as in Example 1, and measurements were performed according to the procedure in Example 1. The chlorine STY after 2 hours of reaction was 1.74 g. Cl2 ·g cat -1 ·h -1 .

[0101] Comparative Example 11

[0102] Compared with Example 1, the only difference is that ammonia precipitation is not used; the difference lies in the following steps:

[0103] According to the conditions of Example 1, a solution was prepared, impregnated with a carrier, directly filtered, dried, and calcined in air at 450°C for 4 hours to obtain the catalyst.

[0104] The determination was performed according to the protocol in Example 1. The chlorine STY after 2 hours of reaction was 1.84 g. Cl2 ·g cat -1 ·h -1 .

[0105] Comparative Example 12

[0106] Compared with Example 1, the only difference is that the calcination temperature is 700℃, while other operations and parameters are the same as in Example 1. Measurements were performed according to the procedure in Example 1, and the result was that the chlorine STY after 2 hours of reaction was 1.10g. Cl2 ·gcat -1 ·h -1 .

[0107] Comparative Example 13

[0108] Compared with Example 1, the only difference is that the calcination temperature is 350°C. All other operations and parameters are the same as in Example 1, and measurements were performed according to the procedure in Example 1. The result was that the chlorine STY after 2 hours of reaction was 1.90 g. Cl2 ·g cat -1 ·h -1 After 40 hours of reaction, the amount of chlorine gas (STY) was 1.21g. Cl2 ·g cat -1 ·h -1 .

[0109] As can be seen from Examples 1-3 and Comparative Examples 1-13, the type of metal component, the stoichiometric range, the one-pot co-impregnation and precipitation method under the action of acid modifier, and the calcination temperature are the key factors in the preparation of the catalyst described in this patent.

[0110] Example 4

[0111] Compared to Example 1, the only difference is that in Example 1, manganese was replaced by an equimolar amount of cobalt. All other operations and parameters were the same as in Example 1, and measurements were performed according to the procedure described in Example 1.

[0112] The catalyst prepared in this case produced 1.98g of chlorine gas (STY) after 2 hours of reaction. Cl2 ·g cat -1 ·h -1 After 146 hours of reaction, the amount of chlorine gas (STY) was 1.98g. Cl2 ·g cat -1 ·h -1 The catalyst activity remains unchanged.

[0113] Example 5

[0114] Compared with Example 1, the only difference is that the calcination temperature is 550°C. Other operations and parameters are the same as in Example 1, and measurements are performed according to the procedure in Example 1.

[0115] The catalyst prepared in this case produced 2.01g of chlorine gas (STY) after 2 hours of reaction. Cl2 ·g cat -1 ·h -1 After 146 hours of reaction, the amount of chlorine gas (STY) was 2.01 g. Cl2 ·g cat -1 ·h-1 , the catalyst activity is unchanged.

[0116] Example 6

[0117] Compared with Example 1, the only difference is that CH3COOH is replaced by CH3CH2CH2COOH in equimolar amount. Other operations and parameters are the same as Example 1, and the determination is made according to the method of Example 1. The STY of chlorine after 2 hours of reaction is 2.12 g Cl2 ·g cat -1 ·h -1 The STY of chlorine after 146 hours of reaction is 2.10 g Cl2 ·g cat -1 ·h -1 , the catalyst activity is unchanged.

[0118] Example 7

[0119] Compared with Example 1, the only difference is that CH3COOH is replaced by CH3COOH and CH3CH2CH2COOH in a molar ratio of 1:1 as the acidic modifier, and the total molar amount of the acidic modifier is the same as Example 1. Other operations and parameters are the same as Example 1. The determination is made according to the method of Example 1, and the STY of chlorine after 2 hours of reaction is 2.35 g Cl2 ·g cat -1 ·h -1 The STY of chlorine after 146 hours of reaction is 2.34 g Cl2 ·g cat -1 ·h -1 , the catalyst activity is unchanged.

[0120] (II): Multiple typical cases of catalytic oxidation

[0121] 2.1: Case of oxygen content;

[0122] Example 8

[0123] Compared with Example 1, the only difference is that the inlet gas ratio under the reaction condition is O2 / HCl=0.5. The STY of chlorine after 2 hours of reaction is 2.47 g Cl2 ·g cat -1 ·h -1 .

[0124] Example 9

[0125] Compared with Example 1, the only difference is that the inlet gas ratio under the reaction condition is O2 / HCl=1. The STY of chlorine after 2 hours of reaction is 2.70 g Cl2 ·g cat-1 ·h -1 .

[0126] 2.2: Case of temperature of catalytic oxidation

[0127] Example 10

[0128] Compared with Example 1, the only difference is that the reaction temperature is 390℃. The chlorine STY after 2 hours of reaction is 2.95g Cl2 ·g cat -1 ·h -1 .

[0129] Example 11

[0130] Compared with Example 1, the only difference is that the reaction temperature is 400℃. The chlorine STY after 2 hours of reaction is 3.16g Cl2 ·g cat -1 ·h -1， The chlorine STY after 146 hours of reaction is 3.16g Cl2 ·g cat -1 ·h -1 The catalyst activity is unchanged.

[0131] It can be seen from Figure 1 , Figure 2 and Figure 3 :

[0132] (1) After stopping oxygen, the three catalysts are fully chlorinated. When oxygen is restored, the three catalysts have consistent recovery trends. Compared with copper lanthanum potassium and copper manganese potassium, the activity of copper manganese lanthanum potassium catalyst recovers rapidly, which fully proves that the copper manganese lanthanum potassium catalyst has the fastest response ability to oxygen.

[0133] (2) After stopping hydrogen chloride, the three catalysts are fully oxidized. When hydrogen chloride is restored, the three catalysts have similar recovery trends, but compared with copper lanthanum potassium and copper manganese potassium, the activity of copper manganese lanthanum potassium catalyst is less affected by the fluctuation of chlorination, which fully proves that copper manganese lanthanum potassium has stronger ability to resist the interference of hydrogen chloride.

[0134] It can be seen from Figure 4 :

[0135] The samples at points A and B in the mechanism experiment of copper manganese lanthanum potassium catalyst were analyzed by XRD. It is found that compared with the samples before and after 100 hours of reaction, the crystal structure has changed but has not yet reached the final crystal structure, indicating that there is a certain process in the evolution of the structure of the catalyst. By comparing the standard peaks, it is found that the existence form of manganese and lanthanum at point A is K 0.5 MnO2, La8Mn8O 23, the existence form at B point is K2MnCl4·2H2O, LaMn7O 12 and La8Mn8O 23 It can be found that manganese and lanthanum synergistically have good storage properties for oxygen or chlorine, ensuring the stability of the copper existing form.

Claims

1. A catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine gas, comprising a carrier and an active ingredient supported thereon, characterized in that, The active ingredient comprises KCuCl3, CuLaO2, K2LaCl5 and active ingredient M: The active ingredient M comprises a Mn-based active ingredient and / or a Co-based active ingredient; The Mn-based active ingredient includes KMnCl3, La8Mn8O 23 and CuMn2O4. The Co-based active ingredient comprises CuCoO2, La2CoO4 and K2CoCl4; The preparation method of the catalyst for preparing chlorine by catalytic oxidation of hydrogen chloride is as follows: The carrier is placed in a metal solution containing a copper source, a metal M source, a lanthanum source and a potassium source, and then subjected to one-pot assisted co-impregnation treatment, and then an alkali is added to the system for co-precipitation to obtain a precursor; and then the precursor is calcined in an oxygen-containing atmosphere to obtain the catalyst; The acid modifier is R-COOH, and R is H or C1-C4 alkyl; The metal M element in the metal M source is manganese and / or cobalt; The calcination temperature is 400-550°C; The molar ratio of Cu, M, La and K in the copper source, the metal M source, the lanthanum source and the potassium source is 1:0.04-0.4:0.1-0.5:0.3-0.5; The copper source, the metal M source, the lanthanum source and the potassium source are chlorides of the respective metals.

2. The catalyst for preparing chlorine by catalytic oxidation of hydrogen chloride according to claim 1, characterized in that The active ingredient M further comprises at least one of CoMnO3 and MnCo2O4.

3. The catalyst for the catalytic oxidation of hydrogen chloride to chlorine as described in claim 1 or 2, characterized in that, The carrier is at least one of active alumina, silicon dioxide, zirconium dioxide and titanium dioxide.

4. The catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine according to claim 3, wherein the catalyst is used in a temperature range of 300 to 400°C. The content of the active ingredient is less than or equal to 40 wt%.

5. A process for the preparation of a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to any one of claims 1 to 4, characterized in that The carrier is placed in a metal solution containing a copper source, a metal M source, a lanthanum source and a potassium source, and then subjected to one-pot assisted co-impregnation treatment, and then an alkali is added to the system for co-precipitation to obtain a precursor; and then the precursor is calcined in an oxygen-containing atmosphere to obtain the catalyst; The acid modifier is R-COOH, and R is H or C1-C4 alkyl; The metal M element in the metal M source is manganese and / or cobalt; The calcination temperature is 400-550°C; The molar ratio of Cu, M, La and K in the copper source, the metal M source, the lanthanum source and the potassium source is 1:0.04-0.4:0.1-0.5:0.3-0.5; The copper source, the metal M source, the lanthanum source and the potassium source are chlorides of the respective metals.

6. The method for producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The molar ratio of the total amount of the copper source, the metal M source, the lanthanum source and the potassium source to the carrier is 1:1-5.

7. The method for preparing the catalyst for the catalytic oxidation of hydrogen chloride to chlorine as described in claim 5, characterized in that, In the acid modifier, R is C2-C3 alkyl.

8. The method for producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 7, wherein The acid modifier comprises R1-COOH and R2-COOH; wherein R1 is methyl and R2 is propyl.

9. The method for producing a catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine according to claim 8, wherein The molar ratio of R1-COOH and R2-COOH is 1:0.5-1.

5.

10. The method for producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The molar ratio of the acid modifier to the total metal is 1-10:

1.

11. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine according to claim 5, wherein The temperature of the co-impregnation stage is 10-60°C; and the time is 5 minutes-24h.

12. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The alkali used in the co-precipitation stage is ammonia.

13. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The pH of the co-precipitation process is 9-10.

14. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to produce chlorine according to claim 5, wherein The treatment time of the co-precipitation stage is 4-8h.

15. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The oxygen-containing atmosphere is at least one of pure oxygen, oxygen-nitrogen mixed gas, oxygen-inert gas mixed gas and air.

16. The method of producing a catalyst for the catalytic oxidation of hydrogen chloride to chlorine according to claim 5, wherein The calcination time is 0.5-6h.

17. A process for the catalytic oxidation of hydrogen chloride to produce chlorine, characterized in that, The catalytic oxidation of HCl and O2 in the presence of a catalyst produces chlorine gas; The catalyst is the catalyst of any one of claims 1-4 or the catalyst prepared by the method of any one of claims 5-16.

18. The method of claim 17, wherein, The molar ratio of O2 / HCl is 0.26-0.

4.

19. The method of claim 18, wherein, The temperature of the catalytic oxidation is 320-450 °C.

20. The method of claim 19, wherein, The temperature of the catalytic oxidation is 370-400 °C.

21. The method of claim 19, wherein, The reaction pressure is 0.1-3.0 MPa.

22. The method of any one of claims 17-21, wherein, The catalytic oxidation is carried out in a fixed bed reactor at a hydrogen chloride volume space velocity of 200 to 20,000 h -1 .

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