Spray needle for liquid phase heterogeneous catalytic reaction and forming process, device and method

Abstract

The application relates to a spray needle for liquid-phase heterogeneous catalytic reaction and a forming process, device and method, and relates to the field of mass spectrum analysis. The spray needle comprises a needle body and a catalyst layer. An inner wall of the needle body is provided with the catalyst layer, the catalyst layer is configured to generate a solid-phase substance of desorption products through liquid-phase reaction flowing through the surface of the catalyst layer, and the needle body is provided with a spray head for spraying the desorption products in a spray state. The detection device comprises the spray needle and a mass spectrometer. An inlet of the mass spectrometer is provided with an electric field, and the spray head is close to the inlet of the mass spectrometer. The application has the effect that the desorption products generated through liquid-phase heterogeneous catalytic reaction can be timely detected by the mass spectrometer by arranging the catalyst layer on the inner wall of the needle body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mass spectrometry, in particular to a spray needle for liquid-phase heterogeneous catalytic reaction, a forming process, device and method. BACKGROUND

[0002] At present, mass spectrometry is an analysis method for detecting ion mass-to-charge ratio. The basic principle of mass spectrometry is that each component in the sample is ionized in the ion source to generate charged ions of different mass-to-charge ratios. After the action of an accelerating electric field, an ion beam is formed and enters the mass analyzer. In the mass analyzer, different mass-to-charge ratio ions are separated in space or time or filtered, and then focused on the detector to obtain a mass spectrum, and then the mass and structure information are analyzed and determined.

[0003] However, the active intermediates of many chemical reactions exist for a very short time, in milliseconds or even microseconds. The reaction zone and ionization zone of the existing electrospray ion source device are separated and connected by a long transmission pipeline, which makes it difficult to detect reaction intermediates with extremely short lifetimes. In addition, the existing electrospray ion source device is mainly applied to homogeneous catalytic reactions and cannot realize heterogeneous catalytic reactions. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a spray needle for liquid-phase heterogeneous catalytic reaction, a forming process, device and method, to solve the technical problem that the desorption products in the liquid-phase heterogeneous catalytic reaction cannot be obtained by the mass spectrometer in time.

[0005] To achieve at least one of the above purposes, the present application provides the following technical solutions:

[0006] In a first aspect, the present application provides a spray needle for online mass spectrometry detection of desorption products generated by liquid-phase heterogeneous catalytic reaction, the spray needle comprising a needle body and a catalyst layer; wherein the inner wall of the needle body is provided with the catalyst layer, and the catalyst layer is configured to react with the solid-phase material flowing through the surface thereof to generate desorption products; the needle body has a spray head for spraying the desorption products in a spray state.

[0007] In the above technical solution, by providing the catalyst layer on the inner wall of the needle body, the liquid phase flows through the surface of the catalyst layer when flowing in the needle body. The desorption products generated by the reaction of the liquid phase and the catalyst layer are sprayed from the spray head. The spray needle serves as a reaction container for liquid-phase heterogeneous catalytic reaction and can also make the desorption products be sprayed in a spray state. The desorption products are ionized in an electric field environment, so that the desorption products sprayed from the spray head can be obtained by the mass spectrometer in time, and online mass spectrometry detection of the desorption products generated by liquid-phase heterogeneous catalytic reaction is realized.

[0008] In some embodiments, the needle body has a nozzle diameter D, wherein 1 μm≤D≤10 μm.

[0009] In some embodiments, the needle body is used to be placed in a high-voltage direct-current electric field environment, so that the desorption products sprayed from the nozzle are in an ionized spray state; or a gas tube coaxial with the needle is arranged at the needle, and atomizing gas is introduced into the gas tube, so that the desorption products sprayed from the nozzle are in a spray state.

[0010] In some embodiments, the nozzle is a member for spraying the liquid phase flowing through the surface of the catalyst layer in a spray state.

[0011] In the second aspect, the application further provides a forming process of the needle, comprising obtaining a needle body; and carrying out catalyst loading to form a catalyst layer on the inner wall of the needle body.

[0012] In the above technical solution, the forming of the needle is realized by forming the catalyst layer on the inner wall of the needle body, and the catalyst layer is fixed on the inner wall of the needle body.

[0013] The forming process of the needle body is relatively simple, which helps to reduce the cost of the needle body.

[0014] The catalyst layer can be formed on the inner wall of the needle body by selecting a suitable loading method according to the type of the catalyst.

[0015] In some embodiments, the needle body is obtained by a manual drawing method; or the needle body is obtained by a machine drawing method.

[0016] In some embodiments, the catalyst loading process comprises an in-situ growth method, an impregnation method, a mechanical coating method, an adhesion method, or a phase transfer method.

[0017] In the third aspect, the application further provides an online detection device for intermediates in a liquid-phase heterogeneous catalytic reaction, comprising a needle and a mass spectrometer; the nozzle is close to the inlet of the mass spectrometer, and a direct-current electric field is arranged between the inlet of the mass spectrometer and the nozzle, so that the desorption products sprayed in a spray state can enter the inlet of the mass spectrometer in an ionized state.

[0018] In the above technical solution, the nozzle and the inlet of the mass spectrometer are in an electric field environment, so that the intermediates in the liquid-phase heterogeneous catalytic reaction are sprayed in a spray state, the intermediates are ionized in the electric field, and the ionized spray enters the inlet of the mass spectrometer, so that the mass spectrometer can timely detect the desorption products.

[0019] The reactor is integrated with the ionization source of the mass spectrometer, and the transmission pipeline is abandoned, so that the active intermediates can become ions and be detected by the mass spectrometer as soon as they are generated.

[0020] The spray needle can be used as a reactor for liquid heterogeneous catalytic reaction, and the reaction occurs under the same conditions as the catalytic reaction process in actual production application, i.e., the reaction occurs under working conditions, and the mass spectrometric detection does not interfere with the progress of the reaction itself.

[0021] The spray needle should be universal and can be adapted to different mass spectrometers and liquid heterogeneous catalytic reactions involving different catalysts.

[0022] In some embodiments, a direct current power supply and an adapter are further included, wherein the adapter is fixedly connected with the needle body, the adapter has a channel connected with the inner cavity of the needle body for feeding the liquid phase into the needle body, and the two poles of the direct current power supply are respectively and conductively connected with the adapter and the inlet of the mass spectrometer.

[0023] In a fourth aspect, the application further provides an online detection method for intermediates in liquid heterogeneous catalytic reaction, comprising a spray needle and a mass spectrometer, and a direct current electric field exists between the spray head and the inlet of the mass spectrometer; the online detection method comprises: flowing the liquid phase on the surface of the catalyst layer in the spray needle, and spraying the liquid phase out of the spray head in a spray state; and the mass spectrometer detects the desorption products entering the inlet of the mass spectrometer in an ionized spray state.

[0024] In the above technical solution, by placing the spray head and the inlet of the mass spectrometer in an electric field environment, the intermediates in the liquid heterogeneous catalytic reaction are sprayed in a spray state, the intermediates are ionized in the electric field, the ionized spray enters the inlet of the mass spectrometer, and the mass spectrometer can timely detect the desorption products. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Figure 1 is a schematic diagram of the principle of a detection device in an embodiment;

[0027] Figure 2 is a schematic diagram of the structure of a detection device in an embodiment.

[0028] The reference signs are as follows:

[0029] 1, needle body; 11, spray head; 2, catalyst layer; 3, adapter; 4, mass spectrometer; 5, solution mixing joint; 9, direct current power supply. DETAILED DESCRIPTION

[0030] The application will be further described by the following drawings and examples. The features and advantages of the present application will become more apparent from the detailed description in conjunction with the drawings.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0032] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another.

[0033] The term "exemplary" as used in the present application means "serving as an example, instance, or illustration." Any implementation described as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Unless specifically stated otherwise, the drawings attached hereto are not drawn to scale.

[0034] In the description of the present application, the technical terms "first", "second", "third" and the like are used only 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 technical features indicated.

[0035] In the description of the present application, the technical term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it.

[0036] In the description of the present application, the technical terms "up", "down", "in", "out", "front", "back", "left", "right", "top", "bottom" and the like indicate the orientation or positional relationship based on the working state of the present application, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0037] In the description of the present application, unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection", "fixed", and the like should be interpreted broadly. For example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium; it can be internal communication of two elements, or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In the description of the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature. It can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it can only mean that the first feature is higher in horizontal height than the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it can only mean that the first feature is lower in horizontal height than the second feature.

[0039] In the present application, "parallel" and "perpendicular" can not only be completely parallel and perpendicular, but also can have a certain error; for example, the included angle between the two is greater than or equal to 0° and less than or equal to 5°, that is, the two are considered to be parallel to each other; the included angle between the two is greater than or equal to 85° and less than or equal to 95°, that is, the two are considered to be perpendicular to each other.

[0040] In the description of the present application, "a plurality of" means two or more (including two), unless specifically defined and limited otherwise.

[0041] In the description of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0042] As part of the inventive concept of the present application, before describing the embodiments of the present application, the causes of the mass spectrometric detection of intermediates in liquid-phase heterogeneous catalytic reactions in the related art are analyzed, and the technical solutions of the embodiments of the present application are obtained through reasonable analysis.

[0043] In the related art, a mass spectrometer includes an ion source, a mass analyzer, and an ion detector. The ion source is a device that ionizes sample molecules under high vacuum conditions. The ionized molecules further fragment into various fragment ions and neutral particles of smaller mass due to receiving excessive energy, and acquire average kinetic energy having the same energy under the action of an acceleration electric field to enter the mass analyzer.

[0044] The mass analyzer is a device that separates ions of different mass that simultaneously enter the mass analyzer according to mass-to-charge ratio m / e. The separated ions sequentially enter the ion detector, collect and amplify the ion signal, and are processed by a computer to draw a mass spectrum.

[0045] Limitations of existing mass spectrometry reaction detection techniques include that mass spectrometry detection of gas phase catalytic reactions can be relatively easily achieved, but mass spectrometry detection of liquid phase reactions is difficult to achieve.

[0046] Although there are mass spectrometry detection methods for liquid phase reactions, they are generally liquid homogeneous reactions, that is, the catalyst is soluble in the solvent, there is no solid-liquid interface, and the reaction is a normal pressure reaction, and the reaction container is a glass vessel.

[0047] In the prior art, the online mass spectrometry detection method of intermediates in high-pressure liquid phase heterogeneous reactions is as follows: a liquid phase heterogeneous reaction occurs in a reaction container, and the active intermediates of the reaction are sent to a mass spectrometer through a transmission pipeline for detection.

[0048] The presence of the transmission pipeline means that the active product must still undergo a relatively long transmission process after being desorbed from the catalyst surface. For this complex solution phase environment, the active product and the inner wall of the transmission pipeline and other reaction products will collide multiple times, and it cannot be guaranteed that the final mass spectrometry detection is the initial active intermediate.

[0049] The active intermediates of the reaction cannot be detected by mass spectrometry as soon as they are generated, causing a time delay between product generation and detection, increasing the risk of quenching and denaturation of active intermediate products, and thus there is still a gap with the realization of in-situ detection of liquid phase heterogeneous reactions.

[0050] Further, the product detected by the prior art is the desorbed product in the solution phase, rather than the active product directly desorbed from the catalyst surface.

[0051] Further, the related prior art actually separates the region where the reaction occurs from the region where mass spectrometry detection occurs, that is, the reaction occurs in the reaction container, and ionization occurs outside the reaction container. In addition to the problems of detection delay and quenching, this also causes a lack of detection of active products on the catalyst surface.

[0052] Heterogeneous catalytic reactions are usually surface processes, that is, the substrate first diffuses to the surface of the catalyst, and then the dissociation or addition reaction occurs on the surface of the catalyst, and finally desorbs to become a product in the liquid phase. The prior art can only detect the product that has diffused to the inlet of the transmission pipeline and passed through the transmission pipeline after desorption from the surface of the catalyst, and cannot detect the active product at the moment of desorption, resulting in the loss of product information.

[0053] To this end, the present application provides a spray needle, comprising a needle body and a catalyst layer, the inner wall of the needle body is provided with the catalyst layer, the catalyst layer is configured to react with the solid phase material flowing through the surface thereof to generate desorption products, and the needle body has a spray head for spraying the desorption products in the form of a spray; thereby solving the technical problem that the mass spectrometer in the prior art cannot obtain the desorption products in the liquid-phase heterogeneous catalytic reaction in time.

[0054] By using the method in the present application, the surface interface reaction link in the liquid-phase heterogeneous catalytic reaction is characterized by using a mass spectrometry method, that is, a series of instantaneous reaction processes of the substrate under the action of the solid catalyst. The mass spectrometry detection method does not affect the progress of the reaction itself, that is, the mass spectrometry detection should be carried out under conditions consistent with the actual reaction process.

[0055] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings. The technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0056] Reference Figure 1 A spray needle for online mass spectrometry detection of desorption products generated by liquid-phase heterogeneous catalytic reaction, the spray needle comprising a needle body 1 and a catalyst layer 2.

[0057] The inner wall of the needle body 1 is provided with the catalyst layer 2, and the catalyst layer 2 is configured to react with the solid phase material flowing through the surface thereof to generate desorption products; the needle body 1 has a spray head 11 for spraying the desorption products in the form of a spray.

[0058] The spray needle is used for online mass spectrometry detection of desorption products generated by liquid-phase heterogeneous catalytic reaction, and the liquid-phase heterogeneous catalytic reaction refers to a chemical reaction in which the reactant is in liquid phase and the catalyst is in solid phase.

[0059] The spray needle in the present embodiment is not applicable to liquid-phase homogeneous catalytic reaction or gas-phase heterogeneous catalytic reaction. These two chemical reactions have different experimental states from the liquid-phase heterogeneous catalytic reaction in the present embodiment. The liquid-phase homogeneous catalytic reaction refers to a chemical reaction in which both the reactant and the catalyst are in liquid phase, and the gas-phase heterogeneous catalytic reaction refers to a chemical reaction in which the reactant is in gas phase and the catalyst is in solid phase.

[0060] The reactants react with the catalyst to form intermediate products, and the desorbed products are the intermediate products in the reaction. The desorbed products are further chemically reacted to form the final products.

[0061] The online mass spectrometry detection is to use the mass spectrometer 4 to detect the desorbed products generated by the liquid-phase heterogeneous catalytic reaction. Since the desorbed products exist for a short time, it is necessary to timely send the generated desorbed products to the inlet of the mass spectrometer 4 for detection.

[0062] The needle body 1 of the spray needle is a quartz tube, one end of the needle body 1 is a liquid inlet, and the other end has a sharp spray head 11. The catalyst layer 2 is configured with solid-phase substances that generate desorbed products by flowing through the surface of the liquid-phase reaction. The composition of the catalyst layer 2 is not fixed, and the composition of the catalyst layer 2 is selected according to the type of the liquid phase. The composition of the catalyst layer 2 is described in the subsequent content.

[0063] The inner wall of the needle body 1 is provided with the catalyst layer 2, and the solid-phase catalyst layer 2 is arranged on the inner wall of the needle body 1, so that the solid-phase catalyst exists in the form of a layer structure on the inner wall of the needle body 1.

[0064] When the liquid phase flows in the inner cavity of the needle body 1, the liquid phase contacts the surface of the catalyst layer 2, and the liquid phase will undergo heterogeneous catalytic reaction. Since the catalyst layer 2 is fixed on the inner wall of the needle body 1, the solid-phase catalyst will not flow to the spray head 11, and the liquid phase will continue to flow from the liquid inlet to the spray head 11. After the liquid phase contacts the surface of the catalyst layer 2, the generated desorbed products flow from the spray head 11 in the form of a spray, so that the subsequent mass spectrometer 4 can timely obtain the desorbed products.

[0065] The spray needle in the embodiment also serves as a catalytic reactor for the liquid-phase heterogeneous catalytic reaction. The spray needle as a catalytic reactor is integrated with the ionization source of the mass spectrometer 4. This further shortens the time for the desorbed products to be detected by the mass spectrometer after being generated.

[0066] It should be noted that heating or light irradiation can be performed during actual reaction detection to realize in-situ mass spectrometry detection of thermal catalytic reaction and photocatalytic reaction.

[0067] The integration of the spray needle in the embodiment on the mass spectrometer 4 can eliminate the transmission pipeline, so that the active desorbed products can be sprayed from the spray head 11 as soon as they are generated and detected by the mass spectrometer 4.

[0068] The spray needle can serve as a reactor for the liquid-phase heterogeneous catalytic reaction. The reaction occurs under conditions consistent with the actual production application of the catalytic reaction process, i.e., the reaction occurs under actual working conditions, and the mass spectrometry detection does not interfere with the performance of the reaction itself.

[0069] The spray needle should be universal, and can be adapted to different mass spectrometers 4 and liquid phase heterogeneous catalytic reactions involving different catalysts.

[0070] With reference to Figure 1 As an optional solution, the diameter of the spray head 11 of the needle body 1 is D, wherein 1 μm≤D≤10 μm.

[0071] The diameter of the spray head 11 in this range enables the liquid phase to be sprayed in a spray state,

[0072] According to general knowledge, the smaller the diameter of the spray head 11, the more difficult and costly the processing of the needle body 1. In this application, a micron-level needle body 1 is used instead of a nanometer-level needle body 1, and the needle body 1 can be processed in more ways, and the processing cost of the micron-level needle body 1 is reduced.

[0073] With reference to Figure 1 As an optional solution, the needle body 1 is used in a high-voltage direct-current electric field environment, so that the desorption products sprayed from the spray head 11 are in an ionized spray state.

[0074] The voltage of the high-voltage direct-current electric field is determined according to the type of the reactant, and the voltage of the high-voltage direct-current electric field is determined according to the voltage of the ionization of the desorption products so that the spray is in an electrospray state.

[0075] When detecting the reaction, the reactant solution is passed into the spray needle at a specific flow rate, and the inlet of the spray needle is grounded or connected to a positive or negative high-voltage electric field, and the tip is close to the inlet of the mass spectrometer 4. When the inlet of the spray needle is grounded and the inlet of the mass spectrometer 4 is negative high-voltage or the spray needle is positive high-voltage and the inlet of the mass spectrometer 4 is grounded, positive ions will be sprayed at the tip. When the inlet of the spray needle is grounded and the inlet of the mass spectrometer 4 is positive high-voltage or the spray needle is negative high-voltage and the inlet of the mass spectrometer 4 is grounded, negative ions will be sprayed at the tip.

[0076] For example, the voltage of the high-voltage direct-current electric field is 5000V. The high-voltage direct-current electric field can spray the desorption products from the spray head 11 in a spray state, and can ionize the desorption products, so that the ionized desorption products can be directly processed by the mass analyzer after entering the inlet of the mass spectrometer 4.

[0077] With reference to Figure 1 As an optional solution, a gas tube coaxial with the spray needle is arranged at the needle head, and atomizing gas is introduced into the gas tube to make the desorption products sprayed from the spray head 11 in a spray state.

[0078] Specifically, a coaxial gas tube is arranged outside the spray needle, and the inner diameter of the gas tube is greater than the outer diameter of the needle body 1, so that the needle body 1 and the gas tube can be two coaxially arranged tubes. Atomizing gas is introduced into the gas tube, and the gas flow in the gas tube flows towards the spray head 11. The gas tube is not shown in the drawings.

[0079] When the liquid phase flows out of the nozzle 11, the liquid phase is atomized at the outlet under the action of the gas flow, so that the desorption products sprayed from the nozzle 11 are in a state of spray.

[0080] A direct current electric field is arranged between the needle and the inlet of the mass spectrometer 4, and the voltage of the direct current electric field should be able to make the desorption products ionized and enter the inlet of the mass spectrometer 4 to be processed by the mass analyzer.

[0081] In other embodiments, other ways can be used to atomize the liquid phase sprayed from the nozzle 11 to form a state of spray, such as using an external light source to irradiate atomization, using external heating to atomize.

[0082] The desorption products in the state of spray are ionized by the direct current electric field and enter the inlet of the mass spectrometer 4 to be processed by the mass analyzer.

[0083] Referring to Figure 1 As an optional solution, the nozzle 11 is a component for spraying the liquid phase flowing through the surface of the catalyst layer 2 in a state of spray.

[0084] The structure of the nozzle 11 not only makes the desorption products sprayed from the nozzle 11 in a state of spray, but also enables the liquid phase in the needle body 1 to be sprayed from the nozzle 11 in a state of spray.

[0085] The application also discloses a forming process of the spray needle, comprising:

[0086] Obtaining the needle body 1;

[0087] Carrying the catalyst to form the catalyst layer 2 on the inner wall of the needle body 1.

[0088] The needle body 1 is drawn from a glass tube with a certain inner diameter. The inner wall of the spray needle can be loaded with different solid catalysts by various physical or chemical methods.

[0089] Referring to Figure 1 As an optional solution, the needle body 1 is obtained by manual drawing or machine drawing.

[0090] The needle body 1 is drawn from a glass tube with a certain inner diameter, and the inner diameter is much larger than that of a conventional nanoelectrospray needle. The glass tube is mechanically or manually drawn to obtain a conical needle tip at one end, and a small hole is opened on the needle tip, that is, a spray needle integrating a liquid phase reactor and an electrospray needle is obtained.

[0091] Referring to Figure 1 As an optional solution, the catalyst carrying process comprises in-situ growth, impregnation, mechanical coating, adhesion or phase transfer.

[0092] In-situ growth method is used for loading catalysts and carriers with specific nanostructures, typical representatives include photocatalysts graphite phase C3N4(g-C3N4), CdIn2S4 and ZnIn2S4 and TiO2. Taking the loading of g-C3N4 as an example:

[0093] ① Hydroxylate the inner wall of the drawn glass nozzle, soak the inner wall with arachidonic acid, and obtain the glass nozzle with hydroxylated inner wall after cleaning.

[0094] ② Further modify the inner wall of the hydroxylated glass nozzle with amino group, use coupling agent 3-aminopropyl triethoxysilane or 3-aminopropyl trimethoxysilane to perform amino modification on the inner wall of the glass tube in anhydrous ethanol or ethanol / water solution.

[0095] ③ Load catalyst precursor urea or melamine into the nozzle for calcination, and obtain the glass nozzle with g-C3N4 loaded on the inner wall.

[0096] The remaining catalysts suitable for in-situ growth method loading all need to include similar processes, i.e. nozzle inner surface pretreatment and precursor in-situ growth.

[0097] Immersion method is suitable for loading metal catalysts, i.e. first load catalyst carrier layer on the inner wall of the nozzle by in-situ growth method, and then load metal particles on the carrier by metal salt precursor immersion method.

[0098] Mechanical coating method is suitable for surface inert catalysts and carriers, such as activated carbon supported noble metal and transition metal catalysts. Such catalysts or carriers lack groups that can be affined to glass, so they can be coated on the inner wall of the frosted glass nozzle by mechanical force. Specifically, first frosted treat the inner wall of the glass nozzle with hydrofluoric acid to increase the surface roughness and specific surface area of the glass, and then fix the catalyst powder on the inner wall of the nozzle by mechanical extrusion or slurry coating method.

[0099] Adhesion method is suitable for catalysts and carriers with more hydroxyl groups on the surface, such as molecular sieves and supported catalysts, supported catalysts with SiO2, Al2O3, other metal oxides as carriers, etc.

[0100] Specifically, first hydroxylate the inner wall of the glass nozzle, then mix the catalyst powder with water or ethanol by grinding method, and adjust it into slurry. Inject the slurry directly into the hydroxylated nozzle inner wall, remove the excess slurry, and a layer of catalyst particles can be adhered on the inner wall of the glass nozzle. After heating and evaporating the solvent, the glass nozzle with catalyst loaded on the inner wall is obtained.

[0101] The phase transfer method is suitable for loading of organic molecular catalysts. Taking loading of fullerene as an example, first, the inner wall of the glass needle is sanded, then the inner wall is subjected to hydroxylation and amination treatment, then a poor solvent of fullerene such as ethanol or tetrahydrofuran is filled into the needle, and then a toluene or benzene solution in which fullerene is dissolved is slowly injected into the inner wall of the needle. At this time, due to the difference in solubility, the fullerene will precipitate in the form of nanoparticles and adhere to the inner wall of the needle. After removing the excess liquid, annealing treatment is performed below 300 DEG C, and a glass needle loaded with fullerene is obtained.

[0102] Referring to Figure 2 The application also discloses an online detection device for intermediates in liquid-phase heterogeneous catalytic reactions, comprising a needle and a mass spectrometer 4. The needle 11 is close to the inlet of the mass spectrometer 4, and a direct-current electric field is arranged between the inlet of the mass spectrometer 4 and the needle 11; so that the desorption products sprayed in the form of spray can enter the inlet of the mass spectrometer 4 in the form of ionization.

[0103] In the application, when the needle is integrated with the ionization source of the mass spectrometer 4, the inlet of the mass spectrometer 4 is the inlet of the mass analyzer of the mass spectrometer 4.

[0104] In another embodiment, the needle can also be arranged outside the mass spectrometer 4, and the spray from the needle enters the inlet of the mass spectrometer 4. Here, the inlet of the mass spectrometer 4 is the inlet of the ion source of the mass spectrometer 4.

[0105] Specifically, there is a high-voltage direct-current electric field (0-±5000V) between the needle head 11 of the needle and the inlet of the mass spectrometer 4. At this time, the liquid phase sprayed from the needle is ionized in the form of spray at the needle head 11, and the obtained ions fly to the inlet of the mass spectrometer 4 and are detected in real time by the rear-end mass spectrometer 4.

[0106] Further, for a thermal catalytic reaction, the needle can be heated by an external heating method. For a photocatalytic reaction, the needle is irradiated by an external light source.

[0107] The detection device of the application integrates the reactor with the electrospray ionization source, and uses a glass needle to realize reaction and ionization without any transmission pipeline.

[0108] The inner wall of the needle is loaded with a solid catalyst, and the loading means can be adjusted according to different types of catalysts.

[0109] The device can perform thermal catalytic and photocatalytic reactions, and the reaction conditions are consistent with the conditions in industrial applications. The mass spectrometric detection is carried out under actual working conditions and does not interfere with the reaction itself.

[0110] Referring to Figure 2As an alternative, the direct current power supply 9 and the adapter 3 are further included, the adapter 3 is fixedly connected with the needle body 1, the adapter 3 has a channel connected with the inner cavity of the needle body 1, and the channel is used for sending the liquid phase into the needle body 1; the two poles of the direct current power supply 9 are respectively and correspondingly in conductive connection with the adapter 3 and the inlet of the mass spectrometer 4.

[0111] Specifically, the detection device further includes a solution mixing adapter 5, a mixed solution sampling tube, a first sampling tube, a second sampling tube, and a third sampling tube.

[0112] The solution mixing adapter 5 has four interfaces, three of which are respectively in communication with the first sampling tube, the second sampling tube, and the third sampling tube, and the other interface is in communication with the mixed solution sampling tube.

[0113] One end of the mixed solution sampling tube is in communication with the solution mixing adapter 5, and the other end is in communication with the adapter 3.

[0114] The adapter 3 is a conductive adapter, and an exemplary adapter 3 is a metal adapter. The direct current power supply 9 is in conductive connection with the adapter 3.

[0115] The spray needle with the catalyst layer 2 carried on the inner wall is in communication with the mixed solution sampling tube through the metal adapter 3, and the mixed solution in the mixed solution sampling tube is derived from the solution mixing adapter 5. Generally, the solution mixing adapter 5 is a four-way adapter, and a total of three reaction solutions can be mixed in the solution mixing adapter 5 through the first sampling tube, the second sampling tube, and the third sampling tube. The flow rate of the solution is controlled by using a syringe pump.

[0116] It should be noted that the mixing of multiple reaction solutions is not necessarily required, and only one solution can be selected as a reaction solution or multiple solutions can be mixed according to the actual system, including but not limited to two, five, or six solutions.

[0117] The direct current high-voltage power supply is connected to the metal adapter 3, so that a high-voltage direct current electric field exists between the spray head 11 of the spray needle and the inlet of the mass spectrometer 4.

[0118] The micro-droplets flowing out of the spray head 11 of the spray needle are subjected to electrospray ionization under the action of the electric field force, and the ions can fly from the spray head 11 to the inlet of the mass spectrometer 4 and be detected, thereby realizing online mass spectrometric detection of catalyst surface species.

[0119] Heterogeneous catalytic reactions are usually surface reactions. Adsorption, activation, reaction, energy transfer, and mass transfer of molecules, atoms, and electrons on the surface interface are the core of catalysis and surface interface chemistry research. The mechanism of traditional gas / solid interface heterogeneous reactions is relatively mature, but the research on the mechanism of liquid / solid interface thermal, optical, and electrical effects still faces difficulties.

[0120] The characterization technology suitable for medium environment such as water, solvent and ionic liquid is the focus and difficulty of the current innovative instrument development. However, for liquid-phase heterogeneous reaction, the current technical means is difficult to detect the reaction / desorption species on the catalyst surface in time, and the bottleneck is that there is a time and space delay between the generation of active product and the detection.

[0121] The application focuses on the reaction process on the catalyst surface, decouples the initial change behavior of the reactant on the catalyst surface from the complex catalytic reaction system, and specially detects the active species desorbed from the catalyst surface in line and quickly.

[0122] The reaction detected by the application occurs under normal pressure, which meets the real working condition of most heterogeneous organic catalytic reactions, and the molecular weight of the key species detected can reflect the evolution of the active species of the real catalytic system, thereby providing a new analysis means for studying liquid-phase heterogeneous catalytic reaction.

[0123] The application has universality and can be applied to most catalysts and catalytic reactions, and can match most commercial mass spectrometers.

[0124] The glass spray needle used in the application is cheap and easy to obtain, and can be manually drawn, thereby greatly reducing the cost of reaction detection.

[0125] Reference Figure 2 The application also discloses an online detection method for intermediates in liquid-phase heterogeneous catalytic reaction, which comprises a spray needle and a mass spectrometer 4.

[0126] The online detection method comprises flowing of liquid phase on the surface of the catalyst layer 2 in the spray needle, and spraying in a spray state from the spray head 11, and there is a direct current electric field between the spray head 11 and the inlet of the mass spectrometer 4, and the mass spectrometer 4 detects the desorption product in the ionized state entering the inlet of the mass spectrometer 4.

[0127] It should be finally pointed out that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application, and they should be covered in the scope of the claims and the specification of the application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way.

[0128] The application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A spray needle, characterized in that The application discloses an on-line mass spectrometry detection method for desorption products generated by liquid-phase heterogeneous catalytic reaction, and a spray needle used in the method. The inner wall of the needle body is provided with the catalyst layer, which is configured to generate desorption products with solid-phase substances flowing through the surface of the catalyst layer. The needle body has a spray head for spraying the desorption products in a spraying state. The needle body is used to be placed in a high-voltage direct-current electric field environment so that the desorption products sprayed from the spray head are in an ionized spraying state. Or a gas tube coaxial with the spray needle is arranged at the needle head, and atomizing gas is introduced into the gas tube so that the desorption products sprayed from the spray head are in a spraying state.

2. The nozzle needle of claim 1, wherein The diameter of the spray head of the needle body is D, wherein 1 μm≤D≤10 μm.

3. A process for forming a nozzle needle as claimed in claim 1 or 2, characterized in that, The application further discloses a preparation method of the spray needle. The needle body is obtained by manual drawing. Or the needle body is obtained by machine drawing.

4. The forming process of claim 3, wherein, The catalyst loading process includes in-situ growth, impregnation, mechanical coating, adhesion or phase transfer. The application further discloses a mass spectrometer.

5. The forming process of claim 3, wherein, The spray head is close to the inlet of the mass spectrometer.

6. An apparatus for online detection of intermediates in liquid phase heterogeneous catalytic reactions, characterized in that, A direct-current electric field is arranged between the inlet of the mass spectrometer and the spray head, so that the desorption products sprayed in a spraying state can enter the inlet of the mass spectrometer in an ionized state. The application further discloses a direct-current power supply and an adapter. The adapter is connected and fixed with the needle body, and the adapter has a channel connected with the inner cavity of the needle body, which is used to send the liquid phase into the needle body.

7. The apparatus for online detection of intermediates in liquid-phase heterogeneous catalytic reactions according to claim 6, characterized in that, The two poles of the direct-current power supply are respectively connected with the adapter and the inlet of the mass spectrometer in a one-to-one conductive manner. The application further discloses a mass spectrometer. The liquid phase flows through the surface of the catalyst layer in the spray needle and is sprayed from the spray head in a spraying state.

8. A method for online detection of intermediates in liquid phase heterogeneous catalytic reactions, characterized in that, The mass spectrometer detects the desorption products entering the inlet of the mass spectrometer in an ionized spraying state. ​ ​ ​

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