A linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions

Abstract

The present invention relates to a linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions, which comprises a gas chamber, a hexapole rod, end cap electrodes, an air inlet device and a heating device. The gas chamber includes an adiabatic shielding housing and two adiabatic baffles, and a cavity is formed between the two adiabatic baffles and the adiabatic shielding housing; the hexapole rod passes through the two adiabatic baffles at both ends; the front and rear end cap electrodes include a front end cap electrode and a rear end cap electrode, and the front end cap electrode and the rear end cap electrode are respectively sleeved at both ends of the gas chamber; the air inlet device is communicated with the cavity and is used for introducing a cooling gas and a reaction gas into the gas chamber; the heating device is located in the cavity and is used for heating the cluster ions, the cooling gas and the reaction gas. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions can stably provide reaction conditions at different temperatures in the range from room temperature to 1000K for the gas-phase cluster reaction.

Description

Technical Field

[0001] The present invention relates to a linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions, and belongs to the research field of high-temperature ion trap reactor devices. Background Art

[0002] The research on gas-phase cluster reactions under controllable and reproducible conditions is widely used to reveal the reaction mechanisms of related condensed phases, providing important theoretical bases for designing new catalysts and their surface active sites. Those reactions without overall energy barriers can occur at room temperature, but for some reactions that are thermodynamically feasible but kinetically hindered, the reactions are very slow or do not occur at room temperature. Due to the limitation of the instrument sensitivity, such reactions are difficult to be directly studied. To overcome this problem, many works have explored different ways to achieve ion heating, which can be mainly divided into two categories: The first category is to introduce ions into a variable-temperature long tube to achieve ion heating. This method can heat ions to a very high temperature (about 1200 K), mainly because the vacuum degree in the tube is relatively low (usually several hundred Pa to thousands of Pa), thus having a high heat transfer efficiency. The second category is to use variable-temperature ion storage devices to heat ions, including ion mobility tubes, ion traps, etc. Among them, ion trap heating has significant advantages such as being suitable for coupling mass selection devices and having clear reaction phenomena, and has great technical advantages.

[0003] However, compared with the high pressure in the flow reaction tube, it is relatively difficult to achieve ion heating under high-vacuum conditions. Mainly, mass-selected clusters are heated to a certain temperature (about 873 K) through thermal radiation. By comparison, it can be found that there is still an obvious gap between the maximum temperature at which the second type of device can achieve ion heating and the first type of device, and many reactions such as pyrolysis under high-temperature conditions need to be observed at higher temperatures, which requires the development of high-temperature ion trap reactor devices with a higher temperature upper limit. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide a linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions. This device can stably provide reaction conditions at different temperatures in the range from room temperature to 1000 K for gas-phase cluster reactions, and can be used to couple devices such as ion sources, mass selectors, and mass spectrometers, making it possible to study the chemical behaviors of cluster ions at temperatures up to 1000 K.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions, including:

[0007] Gas chamber, the gas chamber includes an adiabatic shielding housing and two adiabatic baffles, the two adiabatic baffles are respectively fixedly installed at both ends of the adiabatic shielding housing, and a cavity is formed between the two adiabatic baffles and the adiabatic shielding housing;

[0008] Hexapole rod, the hexapole rod is sleeved in the cavity, the hexapole rod passes through the two adiabatic baffles at both ends, a radio frequency current is applied to the hexapole rod, and cluster ions enter the cavity from one end of the hexapole rod and are confined in the radio frequency field of the hexapole rod;

[0009] End cap electrodes, the end cap electrodes include a front end cap electrode and a rear end cap electrode, the front end cap electrode and the rear end cap electrode are respectively fixed on the two adiabatic baffles, a variable potential is applied between the front end cap electrode and the rear end cap electrode, and the potential is used to control the entry and exit of the cluster ions from the radio frequency field of the hexapole rod;

[0010] Gas inlet device, the gas inlet device is communicated with the cavity and is used to provide cooling gas and reaction gas for the reaction;

[0011] Heating device, the heating device is located in the cavity and is used to heat the cluster ions and the cooling gas and reaction gas.

[0012] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes a cooling device, the cooling device is fixedly installed on the outer side wall of the adiabatic shielding housing and is used to take away the heat dissipated from the adiabatic shielding housing.

[0013] The cooling device is a water-cooling device, the water-cooling device includes a sleeve, the sleeve is fixedly sleeved on the outer side wall of the adiabatic shielding housing, a heat dissipation flow channel, a water inlet and a water outlet are arranged on the side wall of the sleeve, and the water inlet and the water outlet are communicated with the heat dissipation flow channel.

[0014] The heating device includes a ceramic tube support column, a heating wire and a plurality of ceramic insulating gaskets, the plurality of ceramic insulating gaskets are sleeved on the ceramic tube support column, the ceramic insulating gaskets can slide along the ceramic tube support column, the heating wire is spirally wound on the outer wall of the ceramic tube support column, and the ceramic insulating gaskets are used to separate adjacent turns of the heating wire.

[0015] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes two sealed adiabatic gaskets, the two sealed adiabatic gaskets are respectively fixedly installed on the two adiabatic baffles and are used to fix the hexapole rod and seal the gap between the hexapole rod and the adiabatic baffle, and the front end cap electrode and the rear end cap electrode are respectively fixedly installed on the two sealed adiabatic gaskets.

[0016] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes a temperature controller and a temperature detection device. The temperature controller is electrically connected to the heating wire and the temperature detection device. The temperature controller supplies power to the heating wire and receives the signal feedback by the temperature detection device, and controls the heating temperature of the heating wire according to the feedback signal.

[0017] The temperature detection device is a thermocouple. The thermocouple is fixedly installed on the adiabatic baffle, and the probe of the thermocouple is inserted into the cavity.

[0018] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes a focusing mirror. The focusing mirror is fixedly installed at the other end of the hexapole rod and is used for focusing the cluster ions after the reaction.

[0019] Due to the above technical solutions adopted by the present invention, it has the following advantages:

[0020] By arranging an adiabatic shielding housing between the gas chamber and the water-cooled sleeve to weaken heat convection, the fixed winding method of the heating wire, the selection of materials and diameters, and using zirconia ceramics with poor thermal conductivity as the front and rear adiabatic baffles, etc., this device can stably provide reaction conditions at different temperatures in the range from room temperature to 1000 K for the gas-phase cluster reaction, and can be used to couple ion sources, mass selectors, mass spectrometers and other devices, making it possible to study the chemical behavior of cluster ions at temperatures up to 1000 K. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0022] Figure 1 is the overall schematic diagram of the connection between the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions provided by the present invention and other coupling devices;

[0023] Figure 2 is the structural schematic diagram of an embodiment of the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions provided by the present invention;

[0024] Figure 3 is Figure 2 the structural schematic diagram of another angle of the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions in

[0025] Figure 4 is Figure 2 the schematic diagram of the circuit connection between the temperature controller, the heating device and the thermocouple in

[0026] Description of the reference numerals:

[0027] 101 - Laser sputtering ion generation source, 102 - Quadrupole mass selector, 103 - Ion trap device, 104 - Time-of-flight mass spectrometry, 1 - Hexapole, 2 - Front end cap electrode, 3 - Temperature controller, 4 - Rear end cap electrode, 5 - Focusing mirror, 6 - Sealing and heat-insulating gasket, 7 - Heat-insulating shielding housing, 8 - Ceramic tube support, 9 - Ceramic insulating gasket, 10 - Heat-insulating baffle, 11 - Heating wire, 12 - Thermocouple, 13 - Sleeve. Detailed implementation manners

[0028] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, 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 so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0029] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions provided by the embodiment of the present invention includes a gas chamber, end cap electrodes, a hexapole, an air inlet device, and a heating device. The gas chamber includes a heat-insulating shielding housing and two heat-insulating baffles. The two heat-insulating baffles are respectively fixedly installed at both ends of the heat-insulating shielding housing, and a cavity is formed between the two heat-insulating baffles and the heat-insulating shielding housing; the hexapole is sleeved in the cavity, the hexapole passes through the heat-insulating baffles at both ends, a radio frequency current is applied to the hexapole, and cluster ions enter the cavity from one end of the hexapole and are confined in the radio frequency field of the hexapole; the end cap electrodes include a front end cap electrode and a rear end cap electrode, the front end cap electrode and the rear end cap electrode are respectively fixed on the two heat-insulating baffles, and a variable electric potential is applied between the front end cap electrode and the rear end cap electrode, and the electric potential is used to control the entry and exit of the cluster ions from the radio frequency field of the hexapole; the air inlet device is communicated with the cavity and is used to provide cooling gas and reaction gas for the reaction; the heating device is located in the cavity and is used to heat the cluster ions and the cooling gas and reaction gas.

[0030] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions can stably provide reaction conditions at different temperatures in the range from room temperature to 1000 K for the gas-phase cluster reaction, and can be used to couple devices such as an ion generation source, a mass selector, and a mass spectrometer, making it possible to study the chemical behavior of cluster ions at temperatures up to 1000 K.

[0031] Example 1

[0032] As Figures 1 to 4As shown, the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions is mainly used to couple with other devices in the laboratory for the research of gas-phase clusters. The other devices include a laser ablation ion source 101, a quadrupole mass selector 102, and a time-of-flight mass spectrometer 104. The laser ablation ion source 101, the quadrupole mass selector 102, the ion trap device 103, and the time-of-flight mass spectrometer 104 are connected in sequence.

[0033] The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions includes a gas chamber, a hexapole 1, a front end-cap electrode 2, a rear end-cap electrode 4, an air inlet device, a heating device, and a focusing mirror 5. The gas chamber includes an adiabatic shielding housing 7 and two adiabatic baffles 10. The two adiabatic baffles 10 are respectively fixedly installed at both ends of the adiabatic shielding housing 7, and a cavity is formed between the two adiabatic baffles 10 and the adiabatic shielding housing 7.

[0034] The hexapole 1 is sleeved inside the adiabatic shielding housing 7. The hexapole 1 is coaxial with the adiabatic shielding housing 7, and both ends of the hexapole 1 pass through the adiabatic baffles 10 at both ends. The air inlet device is in gas circuit communication with the cavity; the heating device is located inside the cavity and is used to heat the cluster ions and gas inside the hexapole 1.

[0035] Cluster ions enter from one end of the hexapole 1. The hexapole 1 plays a role in constraining and guiding. By applying a radio frequency current on it, the cluster ions can be constrained within the radio frequency field of the hexapole 1 and guided to move along this path.

[0036] The air inlet device is in gas circuit communication with the cavity. Before the cluster ions enter the cavity, a cooling gas is introduced into the gas chamber for preheating. After the cluster ions enter the cavity, they collide with the cooling gas to exchange heat, reach the set temperature, and then a reaction gas is introduced for reaction, and then released after the reaction.

[0037] When the cluster ions reach inside the cavity, a reaction gas is introduced through the air inlet device, and the cluster ions and the reaction gas are heated through the heating device. The cluster ions after the heating reaction are focused and discharged through the focusing mirror 5. The heating device can heat the cluster ions and gas to different temperatures within the range from room temperature to 1000 K.

[0038] The hexapole 1 is composed of a set of six completely identical metal rods. By applying a radio frequency current on it, the cluster ions can be constrained within the radio frequency field of the hexapole 1 and guided to move along this path.

[0039] To prevent the heat of the reaction device from being transferred to other positions except the cavity, the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes a water-cooling device, which is fixedly installed on the outer side wall of the adiabatic shielding housing 7 and is used to take away the heat dissipated from the adiabatic shielding housing 7.

[0040] The water-cooling device includes a sleeve 13, which is fixedly sleeved on the outer side wall of the adiabatic shielding housing 7. A heat dissipation flow channel 133, a water inlet 131 and a water outlet 132 are provided on the wall of the sleeve 13, and the water inlet 131 and the water outlet 132 are communicated with the heat dissipation flow channel 133.

[0041] Cold water enters the heat dissipation flow channel 133 from the water inlet 131 and flows along the heat dissipation flow channel 133. During the flowing process of the cold water, the heat dissipated from the adiabatic shielding housing 7 is taken away, and finally discharged from the water outlet 132.

[0042] It can be understood that the heat dissipation flow channel 133 can be designed into various shapes according to needs, and can be an S shape or other shapes.

[0043] The heating device includes a ceramic tube support 8, a heating wire 11 and a plurality of ceramic insulating gaskets 9. The ceramic tube support 8 is fixedly sleeved in the cavity. The plurality of ceramic insulating gaskets 9 are sleeved on the ceramic tube support 8, and the ceramic insulating gaskets 9 can slide along the ceramic tube support 8. The heating wire 11 is spirally wound around the outer wall of the ceramic tube support 8. The ceramic insulating gaskets 9 are used to isolate adjacent turns of the heating wire 11. The heating wire 11 is made of a nickel-chromium alloy wire (Cr20Ni80) with a diameter of 0.9 mm. Through the arrangement of the ceramic insulating gaskets 9, each turn of the heating wire 11 can be insulated from each other, and the heat can be transferred to the cluster ions and reaction gas in the hexapole rod 1 more evenly.

[0044] The ceramic insulating gasket 9 is in a circular ring shape, and the inner diameter dimension is 0.2 mm larger than that of the ceramic tube support 8. Therefore, it can slide arbitrarily on the ceramic tube support and is not fixed. So the heating wire 11 can choose different winding methods to change the number of turns of the heating wire 11 wound and the total resistance. The more turns the heating wire 11 is wound, the greater the total resistance means. Since the voltage output by the temperature control device is certain, the overall heating power will be smaller; but if the number of turns is too small, the temperature of each turn of the heating wire 11 will be very high, and even will be melted, which is not safe, and the heat transfer is not uniform enough. Therefore, a suitable number of turns needs to be selected.

[0045] To achieve better sealing of the gas chamber and control the movement of cluster ions, the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes two sealed adiabatic gaskets 6. The two sealed adiabatic gaskets 6 are respectively fixedly installed at both ends of the adiabatic baffle 10, and are used to fix the hexapole rod 1 and seal the gap between the hexapole rod 1 and the adiabatic baffle 10. The front end cap electrode 2 and the rear end cap electrode 4 are respectively fixedly installed on the two sealed adiabatic gaskets 6. When the front end cap electrode 2 at the cluster ion inlet is at a low potential, the cluster ions can enter the RF field of the hexapole rod 1 through the small holes on the front end cap electrode 2. The collection time of the cluster ions depends on the reflection effect of the rear end cap electrode 4 on the cluster ions that have entered. Before the cluster ions are reflected out of the inlet, a high potential needs to be applied to the front end cap electrode 2 to close the cluster ion inlet. Then, after the cluster ions are stored for a period of time, a low potential is applied to the rear end cap electrode 4, and the reacted cluster ions are ejected and enter the time-of-flight mass spectrometer for detection.

[0046] Furthermore, to better control the temperature of the heating wire 11, the linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions further includes a temperature controller 3 and a temperature detection device. The temperature controller 3 is electrically connected to the heating wire 11 and the temperature detection device. The temperature controller 3 supplies power to the heating wire 11 and receives the signal fed back by the temperature detection device. The temperature controller 3 controls the heating temperature of the heating wire 11 according to the fed-back signal.

[0047] The temperature detection device is a thermocouple 12. The thermocouple 12 is fixedly installed on the adiabatic baffle 10, and the probe is inserted into the cavity.

[0048] To focus and discharge the cluster ions after the heating reaction, the device for realizing the reaction of gas-phase clusters in a high-temperature environment further includes a focusing lens 5. The focusing lens 5 is fixedly installed at the other end of the hexapole rod 1 and is used to focus the cluster ions after the heating reaction.

[0049] The working principle of the above-mentioned linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions is as follows:

[0050] The temperature controller 3 supplies power to the heating wire 11. After the heating wire 11 is energized, it will generate heat, and the purpose of heating the cluster ions and gas can be achieved through thermal radiation. A water cooling device is added outside the gas chamber, and the water cooling device is externally connected to a circulating water cooler to maintain the temperature of the cooling water in the cavity at about 17 degrees Celsius. The heat energy escaping from the gas chamber can be taken away through heat conduction, thus preventing the heat generated by the heating wire from spreading outside the cavity.

[0051] The linear ion trap device provided by the present invention for realizing the reaction of gas-phase clusters under high-temperature conditions can stably provide reaction conditions at different temperatures in the range from room temperature to 1000 K for gas-phase cluster reactions, and can be used to couple devices such as ion generation sources, mass selectors, and mass spectrometers, making it possible to study the chemical behavior of cluster ions at temperatures up to 1000 K.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions, characterized in that, Comprising: A gas chamber, which includes an adiabatic shielding housing and two adiabatic baffles. The two adiabatic baffles are respectively fixedly installed at both ends of the adiabatic shielding housing, and a cavity is formed between the two adiabatic baffles and the adiabatic shielding housing; A hexapole, which is sleeved in the cavity. The hexapole passes through the two adiabatic baffles at both ends, and a radio frequency current is applied to the hexapole. Cluster ions enter the cavity from one end of the hexapole and are confined in the radio frequency field of the hexapole; End cap electrodes, which include a front end cap electrode and a rear end cap electrode. The front end cap electrode and the rear end cap electrode are respectively fixed on the two adiabatic baffles, and a variable electric potential is applied between the front end cap electrode and the rear end cap electrode. The electric potential is used to control the entry and exit of the cluster ions from the radio frequency field of the hexapole; An intake device, which is communicated with the cavity and is used to provide cooling gas and reaction gas for the reaction; A heating device, which is located in the cavity and is used to heat the cluster ions, the cooling gas and the reaction gas.

2. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 1, wherein It further includes a cooling device, which is fixedly installed on the outer side wall of the adiabatic shielding housing.

3. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 2, wherein The cooling device is a water cooling device, which includes a sleeve. The sleeve is fixedly sleeved on the outer side wall of the adiabatic shielding housing, and a heat dissipation flow channel, a water inlet and a water outlet are arranged on the side wall of the sleeve. The water inlet and the water outlet are communicated with the heat dissipation flow channel.

4. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 1, wherein The heating device includes a ceramic tube support, a heating wire and a plurality of ceramic insulating gaskets. The plurality of ceramic insulating gaskets are sleeved on the ceramic tube support, and the ceramic insulating gaskets can slide along the ceramic tube support. The heating wire is spirally wound on the outer wall of the ceramic tube support, and the ceramic insulating gaskets are used to separate adjacent turns of the heating wire.

5. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 1, wherein, It further includes two sealed adiabatic gaskets, which are respectively fixedly installed on the two adiabatic baffles and are used to fix the hexapole and seal the gap between the hexapole and the adiabatic baffle. The front end cap electrode and the rear end cap electrode are respectively fixedly installed on the two sealed adiabatic gaskets.

6. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 4, wherein It further includes a temperature controller and a temperature detection device. The temperature controller is electrically connected to the heating wire and the temperature detection device. The temperature controller supplies power to the heating wire and receives the signal fed back by the temperature detection device. The temperature controller controls the heating temperature of the heating wire according to the fed-back signal.

7. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 6, characterized in that, The temperature detection device is a thermocouple, which is fixedly installed on the adiabatic baffle, and the probe of the thermocouple is inserted into the cavity.

8. The linear ion trap device for realizing the reaction of gas-phase clusters under high-temperature conditions according to claim 1, wherein, It further includes a focusing mirror, which is fixedly installed at the other end of the hexapole and is used to focus the cluster ions after the reaction.

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