Cobalt chloride catalyst with different hydroxyl contents as well as preparation method and application of cobalt chloride catalyst

Abstract

The invention belongs to the technical field of catalysts, and particularly relates to a cobalt chloride catalyst with different hydroxyl contents and a preparation method and application thereof, the cobalt chloride catalyst with different hydroxyl contents is expressed as CoCl2-mOH, and m is more than or equal to 1.6 wt% and less than or equal to 6.1 wt%; the surface of the cobalt chloride catalyst with different hydroxyl contents has hydroxyl, and the hydroxyl is connected with divalent cobalt in the catalyst. The cobalt chloride catalyst with different hydroxyl contents has no corrosivity, the phase structure is not easy to change in the reaction, and due to the existence of the surface hydroxyl, the HF bond is easy to break, the generation rate of H < + > is accelerated, and the reaction rate of generating the target product HCFC-244bb through the electrophilic addition of HCFO-1233xf and HF is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a cobalt chloride catalyst with different hydroxyl contents and a preparation method and application thereof. Background Art

[0002] At present, the main way to obtain 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in industry is through the liquid phase fluorination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). The reaction process is relatively demanding because the catalyst used is one or more of SbCl5, SnCl4, TaCl5, and TiCl4, especially the highly corrosive SbCl5 catalyst. Therefore, a high-pressure reactor lined with trifluoroethanol (TFE) or soluble polytetrafluoroethylene (PFA) is usually used. In addition, SbCl5 is easily converted to SbCl3 during the reaction, and the catalyst deactivates quickly. Liquid chlorine needs to be added intermittently during the reaction to maintain Sb 5+ , the low catalyst activity and complex reaction process affect the space-time yield of HCFC-244bb.

[0003] To this end, the present invention is proposed. Summary of the invention

[0004] The main purpose of the present invention is to provide a cobalt chloride catalyst with different hydroxyl contents and a preparation method and application thereof. The cobalt chloride catalyst with different hydroxyl contents in the present invention is not corrosive, the physical structure is not easy to change during the reaction, and due to the presence of surface hydroxyl groups, it is easier to break the HF bond, H + The generation rate is accelerated, which increases the reaction rate of the electrophilic addition of HCFO-1233xf and HF to generate the target product HCFC-244bb.

[0005] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0006] In a first aspect of the present invention, a cobalt chloride catalyst having different hydroxyl contents is provided, wherein the cobalt chloride catalyst having different hydroxyl contents is expressed as CoCl2-mOH, wherein 1.6wt%≤m≤6.1wt%; the surface of the cobalt chloride catalyst having different hydroxyl contents has hydroxyl groups, and the hydroxyl groups are connected to the divalent cobalt in the catalyst.

[0007] In some embodiments of the present invention, the cobalt chloride catalysts having different hydroxyl contents are in an octahedral structure, and their physical structure is cobalt chloride.

[0008] In a second aspect of the present invention, a method for preparing the cobalt chloride catalyst with different hydroxyl contents described in the first aspect is provided, wherein the preparation method uses a cobalt source, a chlorine source and a polyol as raw materials, and adopts a preset preparation process to prepare the cobalt chloride catalyst with different hydroxyl contents.

[0009] In some embodiments of the present invention, the cobalt source is selected from one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3.

[0010] In some embodiments of the present invention, the chlorine source is selected from one or more of a gas containing chlorine element, hydrochloric acid, ammonium chloride, and hexachloroethane.

[0011] In some embodiments of the present invention, the polyol is selected from one or more of ethylene glycol, glycerol, and pentaerythritol.

[0012] In some embodiments of the present invention, the preparation process is selected from one of evaporation crystallization, ball milling, equal volume impregnation and gas phase chlorination.

[0013] In some embodiments of the present invention, the gas phase chlorination method is used to prepare the cobalt chloride catalyst with different hydroxyl contents, comprising: impregnating a cobalt source in a polyol, and subjecting the first precursor composite catalyst obtained after the impregnation to a first calcination in a gas atmosphere containing chlorine.

[0014] In some embodiments of the present invention, in the gas phase chlorination method, the molar ratio of the cobalt source to the polyol is 1:(1-2).

[0015] In some embodiments of the present invention, the temperature of the first calcination is 300° C. to 700° C., and the time of the first calcination is 2 h to 6 h.

[0016] In some embodiments of the present invention, the gas containing chlorine element includes at least one of HCl gas and CHFCl2 gas.

[0017] In some embodiments of the present invention, the gas containing chlorine element is selected from a mixed gas of HCl gas and N2 or a mixed gas of CHFCl2 gas and N2.

[0018] In some embodiments of the present invention, the molar ratio of the HCl gas to N2 is 1:(5-10).

[0019] In some embodiments of the present invention, the flow rate of the gas containing chlorine element is 20 mL / min to 100 mL / min.

[0020] In some embodiments of the present invention, the evaporation crystallization method is used to prepare the cobalt chloride catalyst with different hydroxyl contents, comprising: heating a mixed solution of a cobalt source, a chlorine source and a polyol for evaporation crystallization, grinding and drying in sequence.

[0021] In some embodiments of the present invention, the heating temperature is 90°C to 140°C.

[0022] In some embodiments of the present invention, the temperature of the drying treatment is 80° C. to 100° C., and the time of the drying treatment is 15 h to 20 h.

[0023] In some embodiments of the present invention, in the evaporative crystallization method, the molar ratio of the cobalt source, the polyol and the chlorine source is 1:(1-3):(1-6).

[0024] In some embodiments of the present invention, in the evaporative crystallization method, the chlorine source is selected from hydrochloric acid.

[0025] In some embodiments of the present invention, the ball milling method for preparing the cobalt chloride catalyst with different hydroxyl contents comprises: impregnating the ball-milled mixture of the cobalt source and the chlorine source in a polyol, and performing a second calcination on the second precursor composite catalyst obtained after the impregnation in an inert gas atmosphere.

[0026] In some embodiments of the present invention, in the ball milling method, the molar ratio of the cobalt source to the chlorine source is 1:1 to 1:5.

[0027] In some embodiments of the present invention, in the ball milling method, the chlorine source is selected from at least one of ammonium chloride and hexachloroethane.

[0028] In some embodiments of the present invention, in the ball milling method, the molar ratio of the cobalt source to the polyol is 1:2 to 1:7.

[0029] In some embodiments of the present invention, the rotation speed of the ball mill is 200 r / min to 400 r / min, and the time of the ball mill is 2 h to 6 h.

[0030] In some embodiments of the present invention, the temperature of the second calcination is 500° C. to 600° C., and the time of the second calcination is 4 h to 6 h.

[0031] The third aspect of the present invention provides a use of the cobalt chloride catalyst with different hydroxyl contents described in the first aspect or the cobalt chloride catalyst with different hydroxyl contents prepared by the preparation method described in the second aspect in the liquid phase fluorination reaction of HCFO-1233xf to prepare HCFC-244bb.

[0032] In some embodiments of the present invention, the amount of the cobalt chloride catalyst having different hydroxyl contents added is 1% to 4% by mass of HCFO-1233xf.

[0033] Compared with the prior art, the present invention achieves the following technical effects:

[0034] The cobalt chloride catalysts with different hydroxyl contents in the present invention have hydroxyl groups on their surfaces. Due to the presence of hydroxyl groups, it is easier to break the HF bond. + The generation rate is accelerated, which increases the reaction rate of the electrophilic addition of HCFO-1233xf and HF to generate the target product HCFC-244bb.

[0035] The preparation method provided by the invention has the characteristics of short preparation period, low cost, long life and simple operation. The prepared cobalt chloride catalyst with different hydroxyl contents is an environmentally friendly catalyst and can be applied to industrial production.

[0036] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0038] Figure 1 X-ray diffraction (XRD) diagrams of cobalt chloride catalysts with different hydroxyl contents prepared in the examples and comparative examples of the present invention;

[0039] Figure 2 The thermogravimetric analysis (TG) diagrams of cobalt chloride catalysts with different hydroxyl contents prepared in the examples and comparative examples of the present invention. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0042] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0043] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0045] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0046] In order to solve the problems of easy deactivation and strong corrosion of existing SbCl5 catalysts, reduce the reaction process and further accelerate the pace of industrialization of the intermediate HCFC-244bb.

[0047] The present invention provides a cobalt chloride catalyst with different hydroxyl contents, wherein the cobalt chloride catalyst with different hydroxyl contents is expressed as CoCl2-mOH, wherein 1.6wt%≤m≤6.1wt%; the surface of the cobalt chloride catalyst with different hydroxyl contents has hydroxyl groups, wherein the hydroxyl groups are connected to the divalent cobalt in the catalyst.

[0048] In an embodiment of the present invention, based on the total weight of the cobalt chloride catalyst CoCl2-mOH with different hydroxyl contents, the mass percentage of hydroxyl is represented by m, and the value of m can be 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3.0wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt% , 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4.0wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5.0wt%, 5.1wt%, 5.2wt%, 5.3wt%, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5.9wt%, 6.0wt%, 6.1wt% or any value that meets the above range.

[0049] In the embodiment of the present invention, the cobalt chloride catalysts with different hydroxyl contents present an octahedral structure, and the physical structure thereof is cobalt chloride (CoCl2).

[0050] The catalyst of the present invention firstly uses CoCl2, which has a low preparation cost, is non-corrosive and has low requirements on the material of the reactor. Secondly, the complexation between the polyol and the metal chloride makes the structure of the CoCl2-mOH catalyst more stable, and the phase structure is not easy to change during the reaction. Most importantly, the presence of hydroxyl groups in the CoCl2-mOH catalyst makes it easier to break the HF bond. + The generation rate is accelerated, which increases the reaction rate of the electrophilic addition of HCFO-1233xf and HF to generate the target product HCFC-244bb.

[0051] The present invention also provides a method for preparing a cobalt chloride catalyst with different hydroxyl contents, the key of which is to use a complex formed by a monometallic chloride and a polyol to prepare a cobalt chloride catalyst with different hydroxyl contents. Specifically, a cobalt source, a chlorine source and a polyol are used as raw materials, and a preset preparation process is used to prepare a cobalt chloride catalyst with different hydroxyl contents.

[0052] In the embodiments of the present invention, the different hydroxyl contents are caused by the different binding abilities of the cobalt source and the polyols. The main CoCl2 has different affinities for the hydroxyl groups of different alcohols, which affects the number of hydroxyl groups growing on the surface of CoCl2.

[0053] In the embodiment of the present invention, the polyol provides the metal chloride with a number of hydroxyl groups, which greatly enhances the activity of the catalyst. The reason is that the catalytic reaction process belongs to olefin addition, and the carbon cation obtained by the first step of breaking the carbon-carbon double bond and forming a new CH bond is the rate-determining step of the reaction. Increasing the reaction rate of the rate-determining step can greatly reduce the activation energy of the reaction. Therefore, it is necessary to provide more H + To attack the carbon-carbon double bond, H + The main source of HF is HF, and the presence of hydroxyl groups in the CoCl2-mOH catalyst makes it easier for HF bonds to break. + The generation rate is accelerated, which increases the reaction rate of the electrophilic addition of HCFO-1233xf and HF to generate the target product HCFC-244bb.

[0054] In some embodiments of the present invention, the cobalt source is selected from one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3.

[0055] In some embodiments of the present invention, the polyol is selected from one or more of ethylene glycol, glycerol, and pentaerythritol.

[0056] In some embodiments of the present invention, the chlorine source is selected from one or more of a gas containing chlorine element, hydrochloric acid, ammonium chloride (NH4Cl), and hexachloroethane (C2Cl6).

[0057] In some embodiments of the present invention, the gas containing chlorine element includes at least one of HCl gas and CHFCl2 (monochloromethane) gas.

[0058] In some embodiments of the present invention, the preparation process is selected from one of evaporation crystallization, ball milling, equal volume impregnation and gas phase chlorination.

[0059] Gas phase chlorination

[0060] In some embodiments of the present invention, a gas phase chlorination method is used to prepare cobalt chloride catalysts with different hydroxyl contents.

[0061] In an embodiment of the present invention, a cobalt source is impregnated in a polyol, and the first precursor composite catalyst obtained after the impregnation is first calcined in a gas atmosphere containing chlorine element to obtain cobalt chloride catalysts with different hydroxyl contents.

[0062] In some embodiments of the present invention, in the gas phase chlorination method, the molar ratio of the cobalt source to the polyol is 1:(1-2), for example, the molar ratio of the cobalt source to the polyol can be one of 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.6, 1:1.8, 1:2 or any value satisfying the above range.

[0063] In some embodiments of the present invention, in the gas phase chlorination method, the gas containing chlorine element can be a mixed gas of HCl gas and N2, or a mixed gas of CHFCl2 gas and N2.

[0064] In some embodiments of the present invention, in the mixed gas of HCl gas and N2, the molar ratio of HCl gas to N2 is 1:(5-10), for example, the molar ratio of HCl gas to N2 can be one of 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or any value satisfying the above range.

[0065] In some embodiments of the present invention, the flow rate of the gas containing chlorine element is 20mL / min~100mL / min. The flow rate of the gas containing chlorine element provided by the present invention can be the value of the interval composed of any two values ​​in the above interval, such as 20mL / min~60mL / min, or 60mL / min~100mL / min, and so on. The flow rate of the gas containing chlorine element provided by the present invention can also be 20mL / min, 30mL / min, 40mL / min, 50mL / min, 60mL / min, 70mL / min, 80mL / min, 90mL / min, 100mL / min or any numerical value that meets the above range value.

[0066] In some embodiments of the present invention, the temperature of the first calcination is 300°C to 700°C. The temperature of the first calcination provided by the present invention can be a value of an interval composed of any two values ​​in the above range, for example, it can be 300°C to 400°C, it can also be 400°C to 500°C, it can also be 500°C to 700°C, and so on. The temperature of the first calcination provided by the present invention can also be 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C or any value that meets the above range.

[0067] In some embodiments of the present invention, the first calcination time is 2h to 6h. The first calcination time provided by the present invention can be a value of an interval composed of any two values ​​in the above interval, such as 2h to 3h, 3h to 4h, 4h to 6h, and so on. The first calcination time provided by the present invention can also be one of 2h, 3h, 4h, 5h, 6h or any value that meets the above range.

[0068] In some embodiments of the present invention, the cobalt source of the gas phase chlorination method can be one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3.

[0069] In some embodiments of the present invention, the polyol in the gas phase chlorination method may be one or more of ethylene glycol, glycerol, and pentaerythritol.

[0070] In some embodiments of the present invention, the first calcination may be performed in a tube furnace, and a gas containing chlorine element is introduced into the tube furnace.

[0071] In an embodiment of the present invention, a cobalt source is impregnated in a polyol, and the molar ratio of the cobalt source to the polyol is 1:(1-2). The first precursor composite catalyst after impregnation is subjected to a first calcination at 300°C to 700°C in a gas atmosphere containing chlorine element, and the calcination time is 2h to 6h. After cooling, cobalt chloride catalysts with different hydroxyl contents are collected.

[0072] Ball milling

[0073] In some embodiments of the present invention, cobalt chloride catalysts with different hydroxyl contents are prepared by ball milling.

[0074] In an embodiment of the present invention, the ball-milled mixture of the cobalt source and the chlorine source is impregnated in a polyol, and the second precursor composite catalyst obtained after the impregnation is subjected to a second calcination in an inert gas atmosphere to obtain cobalt chloride catalysts with different hydroxyl contents.

[0075] In some embodiments of the present invention, in the ball milling method, the molar ratio of the cobalt source to the chlorine source is 1:1 to 1:5. The molar ratio of the cobalt source to the chlorine source provided by the present invention can be a value in the interval composed of any two values ​​in the above interval, for example, it can be 1:1 to 1:3, it can also be 1:3 to 1:4, it can also be 1:4 to 1:5, and so on. The molar ratio of the cobalt source to the chlorine source provided by the present invention can be one of 1:1, 1:2, 1:3, 1:4, 1:5 or any value that satisfies the above range value.

[0076] In some embodiments of the present invention, the chlorine source in the ball milling method can be at least one of ammonium chloride and hexachloroethane.

[0077] In some embodiments of the present invention, the cobalt source for the ball milling method may be one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3.

[0078] In some embodiments of the present invention, the polyol produced by the ball milling method may be one or more of ethylene glycol, glycerol, and pentaerythritol.

[0079] In some embodiments of the present invention, in the ball milling method, the molar ratio of the cobalt source to the polyol is 1:2 to 1:7. The molar ratio of the cobalt source to the polyol provided by the present invention can be a value in the interval composed of any two values ​​in the above interval, for example, it can be 1:2 to 1:3, it can also be 1:3 to 1:5, it can also be 1:5 to 1:7, and so on. The molar ratio of the cobalt source to the polyol provided by the present invention can be one of 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 or any value that satisfies the above range value.

[0080] In some embodiments of the present invention, the speed of the ball mill is 200r / min to 400r / min. The speed of the ball mill provided by the present invention can be the value of the interval composed of any two values ​​in the above interval, such as 200r / min to 300r / min, or 300r / min to 400r / min, and so on. The speed of the ball mill provided by the present invention can be 200r / min, 210r / min, 220r / min, 230r / min, 240r / min, 250r / min, 260r / min, 270r / min, 280r / min, 290r / min, 300r / min, 310r / min, 320r / min, 330r / min, 340r / min, 350r / min, 360r / min, 370r / min, 380r / min, 390r / min, 400r / min or any value that meets the above range value.

[0081] In some embodiments of the present invention, the ball milling time is 2h to 6h. The ball milling time provided by the present invention can be a value of an interval composed of any two values ​​in the above interval, such as 2h to 3h, 3h to 5h, 5h to 6h, and so on. The ball milling time provided by the present invention can be one of 2h, 3h, 4h, 5h, 6h or any value that meets the above range.

[0082] In some embodiments of the present invention, the temperature of the second calcination is 500° C. to 600° C. The temperature of the second calcination provided by the present invention can be one of 500° C., 550° C., 600° C. or any value satisfying the above range.

[0083] In some embodiments of the present invention, the second calcination time is 4 hours to 6 hours. The second calcination time provided by the present invention can be one of 4 hours, 5 hours, 6 hours or any value satisfying the above range.

[0084] In some embodiments of the present invention, the inert gas may be, but is not limited to, nitrogen.

[0085] In some embodiments of the present invention, the second calcination may be performed in a tube furnace.

[0086] In some embodiments of the present invention, a cobalt source and a chlorine source are mixed and placed in a ball mill, the molar ratio of the cobalt source to the chlorine source is 1:1 to 1:5, the ball mill speed is 200 r / min to 400 r / min, and the ball milling time is 2 h to 6 h. The ball-milled product is then immersed in a polyol, and the molar ratio of the cobalt source to the polyol is 1:2 to 1:7. The impregnated second precursor composite catalyst is subjected to a second calcination at 500°C to 600°C in an inert gas atmosphere for 4 h to 6 h. After cooling, the cobalt chloride catalyst with different hydroxyl contents is collected.

[0087] Evaporation crystallization

[0088] In some embodiments of the present invention, cobalt chloride catalysts with different hydroxyl contents are prepared by evaporation crystallization.

[0089] In an embodiment of the present invention, a mixed solution of a cobalt source, a chlorine source and a polyol is subjected to heating, evaporation, crystallization, grinding and drying treatments in sequence to prepare cobalt chloride catalysts with different hydroxyl contents.

[0090] In some embodiments of the present invention, in the evaporative crystallization method, the molar ratio of the cobalt source, the polyol and the chlorine source is 1: (1-3): (1-6). The molar ratio of the cobalt source, the polyol and the chlorine source provided by the present invention can be a value of an interval composed of any two values ​​in the above interval, for example, it can be 1: (1-2): (1-3), or it can be 1: (2-3): (3-6), and so on. The molar ratio of the cobalt source, the polyol and the chlorine source provided by the present invention can be 1: 1: 1, 1: 1: 2, 1: 1: 3, 1: 1: 4, 1: 1: 5, 1: 1: 6, 1: 2: 1, 1: 2: 2, 1: 2: 3, 1: 2: 4, 1: 2: 5, 1: 2: 6, 1: 3: 1, 1: 3: 2, 1: 3: 3, 1: 3: 4, 1: 3: 5, 1: 3: 6 or any value that satisfies the above range value.

[0091] In some embodiments of the present invention, the chlorine source of the evaporative crystallization method is selected from hydrochloric acid.

[0092] In some embodiments of the present invention, the cobalt source of the evaporation crystallization method can be one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3.

[0093] In some embodiments of the present invention, the polyol used in the evaporative crystallization method may be one or more of ethylene glycol, glycerol, and pentaerythritol.

[0094] In some embodiments of the present invention, the heating temperature is 90°C to 140°C. The heating temperature provided by the present invention can be a value in the interval composed of any two values ​​in the above range, for example, it can be 90°C to 100°C, it can also be 100°C to 120°C, it can also be 120°C to 140°C, and so on. The heating temperature provided by the present invention can also be one of 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or any value that meets the above range.

[0095] In some embodiments of the present invention, the evaporation and crystallization are followed by grinding, and then the mixture is transferred to a forced air drying oven for further drying.

[0096] In some embodiments of the present invention, the drying temperature is 80° C. to 100° C. For example, the drying temperature may be 80° C., 85° C., 90° C., 95° C., 100° C., or any value within the above range.

[0097] In some embodiments of the present invention, the drying time is 15 hours to 20 hours. For example, the drying time can be one of 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, and 20 hours, or any value within the above range.

[0098] In some embodiments of the present invention, a mixed solution of the cobalt source, the polyol and the chlorine source is placed in an oil bath for heating and evaporation and crystallization.

[0099] In some embodiments of the present invention, a cobalt source is placed in a mixed solution of a polyol and a chlorine source, wherein the molar ratio of the cobalt source, the polyol and the chlorine source is 1:(1-3):(1-6), and heated for evaporation and crystallization at a temperature of 90°C to 140°C. After evaporation and crystallization, grinding and drying are performed at a drying temperature of 80°C to 100°C and a drying time of 15h to 20h to obtain cobalt chloride catalysts with different hydroxyl contents.

[0100] The present invention also provides an application of the cobalt chloride catalyst with different hydroxyl contents or the cobalt chloride catalyst with different hydroxyl contents prepared by the preparation method in the reaction of preparing HCFC-244bb by liquid phase fluorination of HCFO-1233xf.

[0101] In some embodiments of the present invention, the amount of cobalt chloride catalyst with different hydroxyl content added is 1% to 4% of the mass of HCFO-1233xf. For example, the amount of catalyst added can be one of 1%, 2%, 3%, 4% of the mass of HCFO-1233xf or any value that meets the above range.

[0102] In some embodiments of the present invention, in the liquid phase fluorination reaction of HCFO-1233xf to prepare HCFC-244bb, the reaction temperature is 70° C. to 130° C., the reaction pressure is 0 to 1.3 MPa, and the reaction time is 4 h to 10 h.

[0103] The reaction temperature provided by the present invention can be a value in the interval composed of any two values ​​in the above range, for example, it can be 70°C to 90°C, 90°C to 110°C, 110°C to 130°C, and so on. The reaction temperature provided by the present invention can also be one of 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, or any value that satisfies the above range.

[0104] The reaction time provided by the present invention can be a value of an interval consisting of any two values ​​within the above range, for example, it can be 4h to 6h, 6h to 8h, 8h to 10h, and so on. The reaction time provided by the present invention can also be one of 4h, 5h, 6h, 7h, 8h, 9h, 10h or any value that meets the above range.

[0105] The reaction pressure provided by the present invention can be a value of an interval composed of any two values ​​in the above range, for example, it can be 0-0.6MPa, it can also be 0.6MPa-1MPa, it can also be 1MPa-1.3MPa, and so on. The reaction pressure provided by the present invention can also be one of 0, 0.1MPa, 0.2MPa, 0.4MPa, 0.5MPa, 0.6MP, 0.8MPa, 1.0MPa, 1.2MPa, 1.3MPa or any value that meets the above range.

[0106] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0107] Example 1

[0108] A cobalt chloride catalyst CoCl2-mOH with different hydroxyl contents, m being 1.6wt%, and its preparation method is as follows:

[0109] 0.05 mol CoCO3 was impregnated in 0.05 mol ethylene glycol, and the impregnated precursor composite catalyst was placed in a tubular furnace, and a mixture of HCl gas and N2 was introduced, wherein the molar ratio of HCl gas to N2 was 1:5, and the flow rate of HCl gas was 40 mL / min. The catalyst was calcined at 400°C for 3 h, and after cooling, cobalt chloride catalysts with different hydroxyl contents were collected for later use.

[0110] The cobalt chloride catalysts with different hydroxyl contents prepared above are used in the liquid phase fluorination of HCFO-1233xf to prepare HCFC-244bb. The reaction formula is as follows (1):

[0111]

[0112] The reaction conditions are as follows: after adding 1g of cobalt chloride catalyst with different hydroxyl contents into a 2L high-pressure reactor, N2 is used for pressure maintenance and leak detection, the pressure is 1.5Mpa, and the pressure maintenance time is 10h. After the pressure maintenance is completed, the pressure is released and the material is added. 50g HCFO-1233xf and 150g anhydrous hydrogen fluoride (AHF) are added to the high-pressure reactor through the gas phase port. The reaction temperature is 90°C, the reaction pressure is controlled at 0.6MPa, and the reaction time is 6h. After the reaction is completed, the exhaust valve is slowly opened, and the mixed gas passes through the alkali solution absorption system and then collected using a cold trap.

[0113] The crude product obtained in Example 1 was subjected to chromatographic analysis, and the results showed that the conversion rate of the reactant HCFO-1233xf was 86.2%, the selectivity of HCFC-244bb was 89.71%, and the selectivity of 1,1,1,2,2-pentafluoropropane (HFC-245cb) was 7.12%.

[0114] Example 2

[0115] A cobalt chloride catalyst CoCl2-mOH with different hydroxyl contents, m being 6.1wt%, and its preparation method is as follows:

[0116] In a 500mL beaker, add 0.05mol Co(NO3)2, propylene glycol and hydrochloric acid solution in sequence, the molar ratio of Co(NO3)2, propylene glycol and hydrochloric acid is 1:1.5:2, heat for evaporation and crystallization at 100°C, grind and dry after evaporation and crystallization at 100°C for 18h, and obtain cobalt chloride catalysts with different hydroxyl contents for use.

[0117] The cobalt chloride catalysts with different hydroxyl contents prepared above are used in the reaction of preparing HCFC-244bb by liquid phase fluorination of HCFO-1233xf. The reaction formula is the same as formula (1).

[0118] The reaction conditions were the same as those in Example 1, except that the reaction temperature was 110° C., the reaction pressure was controlled at 1 MPa, and the reaction time was 8 h.

[0119] The crude product obtained in Example 2 was subjected to chromatographic analysis, and the results showed that the conversion rate of the reactant HCFO-1233xf was 89.2%, the selectivity of HCFC-244bb was 90.63%, and the selectivity of 1,1,1,2,2-pentafluoropropane (HFC-245cb) was 7.51%.

[0120] Example 3

[0121] A cobalt chloride catalyst CoCl2-mOH with different hydroxyl contents, m being 4.2wt%, and its preparation method is as follows:

[0122] 0.05 mol Co(C2H3O2)2 and 0.15 mol NH4Cl were mixed and ball-milled at a speed of 400 r / min for 3 h. The ball-milled product was immersed in pentaerythritol at a molar ratio of Co(C2H3O2)2 to pentaerythritol of 1:3. The impregnated precursor composite catalyst was placed in a tubular furnace and calcined at 500°C for 4 h under a nitrogen atmosphere. After cooling, the cobalt chloride catalysts with different hydroxyl contents were collected and set aside.

[0123] The cobalt chloride catalysts with different hydroxyl contents prepared above are used in the reaction of preparing HCFC-244bb by liquid phase fluorination of HCFO-1233xf. The reaction formula is the same as formula (1).

[0124] The reaction conditions were the same as those in Example 1, except that the reaction temperature was 100° C., the reaction pressure was controlled at 0.8 MPa, and the reaction time was 7 h.

[0125] The crude product obtained in Example 3 was subjected to chromatographic analysis, and the results showed that the conversion rate of the reactant HCFO-1233xf was 86.22%, the selectivity of HCFC-244bb was 90.66%, and the selectivity of 1,1,1,2,2-pentafluoropropane (HFC-245cb) was 6.53%.

[0126] Comparative Example 1

[0127] Commercially available CoCl2 and ethylene glycol are used as catalysts in the liquid phase fluorination of HCFO-1233xf to prepare HCFC-244bb. The reaction formula is the same as formula (1).

[0128] The reaction conditions were the same as those in Example 1, except that 1 g of CoCl2 and 20 mL of ethylene glycol were added to the autoclave as catalysts.

[0129] The crude product obtained in Comparative Example 1 was subjected to chromatographic analysis, and the results showed that the conversion rate of the reactant HCFO-1233xf was 10.2%, the selectivity of HCFC-244bb was 94.78%, and the selectivity of 1,1,1,2,2-pentafluoropropane (HFC-245cb) was 4.75%.

[0130] Comparative Example 2

[0131] 0.05 mol Co(C2H3O2)2 and 0.15 mol NH4Cl were mixed and ball-milled at a speed of 400 r / min for 3 h. The ball-milled product was then dried in a blower dryer and the CoCl2 catalyst was collected for later use.

[0132] The CoCl2 catalyst prepared above is used in the liquid phase fluorination of HCFO-1233xf to prepare HCFC-244bb. The reaction formula is the same as formula (1).

[0133] The reaction conditions were the same as those in Example 1, except that 1 g of CoCl2 prepared in Comparative Example 2 was added to the high-pressure reactor as a catalyst; the reaction temperature was 100° C., the reaction pressure was controlled at 0.8 MPa, and the reaction time was 7 h.

[0134] The crude product obtained in Comparative Example 2 was subjected to chromatographic analysis, and the results showed that the conversion rate of the reactant HCFO-1233xf was 17.39%, the selectivity of HCFC-244bb was 93.02%, and the selectivity of 1,1,1,2,2-pentafluoropropane (HFC-245cb) was 6.65%.

[0135] Performance Testing

[0136] In order to verify the presence of hydroxyl groups on the surface of the CoCl2-mOH (1.6wt%≤m≤6.1wt%) catalyst in the present invention, the catalysts prepared in Example 1, Example 2, Example 3 and Comparative Example 2 were characterized by XRD and TG. The results are as follows: Figure 1-2 shown.

[0137] It can be observed from the figure that the mass loss in the temperature range of 100°C on the TG curve corresponds to the weight loss of physically adsorbed water molecules on the main CoCl2, and the mass loss in the temperature range of 100°C to 700°C is attributed to the removal of hydroxyl groups in CoCl2; the weight loss percentage of Comparative Example 2 is about 2.6%, and only physically adsorbed water is lost; while the weight loss percentage of Example 1 is about 4.2%, the weight loss percentage of Example 2 is about 8.7%, and the weight loss percentage of Example 3 is about 6.8%. This result further shows that there is no hydroxyl content in the catalyst of Comparative Example 2, and the catalysts of Examples 1, 2 and 3 contain different hydroxyl contents, and the presence of hydroxyl groups in the catalyst increases the reaction rate.

[0138] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A cobalt chloride catalyst having different hydroxyl contents, characterized in that: The cobalt chloride catalysts with different hydroxyl contents are expressed as CoCl2-mOH, wherein 1.6wt%≤m≤6.1wt%; The surfaces of the cobalt chloride catalysts with different hydroxyl contents have hydroxyl groups, and the hydroxyl groups are connected to the divalent cobalt in the catalyst.

2. The cobalt chloride catalyst with different hydroxyl contents as claimed in claim 1, characterized in that The cobalt chloride catalyst with different hydroxyl contents presents an octahedral structure, and its physical phase structure is cobalt chloride.

3. A method for preparing a cobalt chloride catalyst having different hydroxyl contents according to any one of claims 1 to 2, characterized in that: The preparation method uses a cobalt source, a chlorine source and a polyol as raw materials and adopts a preset preparation process to prepare the cobalt chloride catalyst with different hydroxyl contents.

4. The preparation method according to claim 3, characterized in that: The cobalt source is selected from one or more of Co(C2H3O2)2, Co(NO3)2, and CoCO3; Preferably, the chlorine source is selected from one or more of a gas containing chlorine, hydrochloric acid, ammonium chloride, and hexachloroethane; Preferably, the polyol is selected from one or more of ethylene glycol, glycerol and pentaerythritol.

5. The preparation method according to claim 3, characterized in that: The preparation process is selected from one of evaporation crystallization method, ball milling method, equal volume impregnation method and gas phase chlorination method.

6. The preparation method according to claim 5, characterized in that: The method of preparing the cobalt chloride catalyst having different hydroxyl contents by the gas phase chlorination method comprises: The cobalt source is impregnated in a polyol, and the first precursor composite catalyst obtained after the impregnation is first calcined in a gas atmosphere containing chlorine element; Preferably, in the gas phase chlorination method, the molar ratio of the cobalt source to the polyol is 1:(1-2); Preferably, the temperature of the first calcination is 300°C to 700°C, and the time of the first calcination is 2h to 6h; Preferably, the gas containing chlorine element includes at least one of HCl gas and CHFCl2 gas; Preferably, the gas containing chlorine element is selected from a mixed gas of HCl gas and N2 or a mixed gas of CHFCl2 gas and N2; Preferably, the molar ratio of the HCl gas to N2 is 1:(5-10); Preferably, the flow rate of the gas containing chlorine element is 20 mL / min to 100 mL / min.

7. The preparation method according to claim 5, characterized in that: The method of preparing the cobalt chloride catalyst having different hydroxyl contents by the evaporation crystallization method comprises: The mixed solution of the cobalt source, the chlorine source and the polyol is heated, evaporated, crystallized, ground and dried in sequence; Preferably, the heating temperature is 90°C to 140°C; Preferably, the temperature of the drying treatment is 80°C to 100°C, and the time of the drying treatment is 15h to 20h; Preferably, in the evaporation crystallization method, the molar ratio of the cobalt source, the polyol and the chlorine source is 1:(1-3):(1-6); Preferably, in the evaporative crystallization method, the chlorine source is selected from hydrochloric acid.

8. The preparation method according to claim 5, characterized in that: The method of preparing the cobalt chloride catalyst having different hydroxyl contents by the ball milling method comprises: The ball-milled mixture of the cobalt source and the chlorine source is impregnated in a polyol, and the second precursor composite catalyst obtained after the impregnation is subjected to a second calcination in an inert gas atmosphere; Preferably, in the ball milling method, the molar ratio of the cobalt source to the chlorine source is 1:1 to 1:5; Preferably, in the ball milling method, the chlorine source is selected from at least one of ammonium chloride and hexachloroethane; Preferably, in the ball milling method, the molar ratio of the cobalt source to the polyol is 1:2 to 1:7; Preferably, the rotation speed of the ball mill is 200 r / min to 400 r / min, and the ball milling time is 2 h to 6 h; Preferably, the temperature of the second calcination is 500° C. to 600° C., and the time of the second calcination is 4 h to 6 h.

9. Use of the cobalt chloride catalyst with different hydroxyl contents according to any one of claims 1 to 2 or the cobalt chloride catalyst with different hydroxyl contents prepared by the preparation method according to any one of claims 3 to 8 in the reaction of preparing HCFC-244bb by liquid phase fluorination of HCFO-1233xf.

10. The use according to claim 9, characterized in that The added amount of the cobalt chloride catalyst with different hydroxyl contents is 1% to 4% of the mass of HCFO-1233xf.

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