JP2021053619A - Carbonyl sulfide decomposition device and carbonyl sulfide detection device - Google Patents

Abstract

To provide a carbonyl sulfide detection device which can stably perform a catalyst reaction of carbonyl sulfide even under such an environment that a volatile component such as a fluorine-based coolant and a detergent used often in a semiconductor factory is present.SOLUTION: A carbonyl sulfide detection device 100 includes a carbonyl sulfide decomposition part 30 for subjecting carbonyl sulfide to catalytic reaction including at least hydrolysis, and a gas detection part 40 for detecting a component in detected gas G generated by catalyst reaction of the carbonyl sulfide by the carbonyl sulfide decomposition part 30. The carbonyl sulfide decomposition part 30 includes a catalyst part 31 having a catalyst 31b for subjecting the carbonyl sulfide to the catalyst reaction including at least the hydrolysis, and a heating mechanism 32 for causing the catalyst reaction. The catalyst 31b contains alkali earth metal silicate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a carbonyl sulfide decomposition device and a carbonyl sulfide detection device, and more particularly to a carbonyl sulfide decomposition device and a carbonyl sulfide detection device that catalytically react carbonyl sulfide with a catalyst.

Carbonyl sulfide is attracting attention as a dry etching gas having an effect of suppressing a shape abnormality called boeing due to passivation, which is the formation of a protective film on the side wall of a pattern-etched structure in the microfabrication of a semiconductor device. On the other hand, the permissible concentration of carbonyl sulfide is regulated from the viewpoint of toxicity. In the United States, the ACGIH (American Conference of Governmental Industrial Hygienists) regulates a time-weighted average permissible concentration of carbonyl sulfide (TLV-TWA) of 5 ppm.

Therefore, it is necessary to appropriately detect leakage from the semiconductor device manufacturing process.

Conventionally, a carbonyl sulfide detector for catalytically reacting carbonyl sulfide with a catalyst is known (see, for example, Patent Document 1).

The above-mentioned Patent Document 1 discloses a carbonyl sulfide measuring device (carbonyl sulfide detecting device) for measuring the concentration of carbonyl sulfide. This carbonyl sulfide measuring device includes activated alumina, which is a catalyst for catalytically reacting carbonyl sulfide, and an electrochemical sensor that measures the concentration of hydrogen sulfide generated by catalytically reacting carbonyl sulfide. This carbonyl sulfide measuring device does not directly measure the concentration of carbonyl sulfide, but converts the concentration of hydrogen sulfide generated by catalytically reacting (hydrolyzing) carbonyl sulfide into the concentration of carbonyl sulfide to obtain carbonyl sulfide. It is configured to measure the concentration indirectly.

JP-A-2017-3534

Here, although not specified in Patent Document 1, volatile components such as Garden, Fluorinert, and Novec are often used as fluorine-based refrigerants in semiconductor factories, and alcohols and the like are volatile as cleaning agents. Ingredients are often used. Therefore, when the carbonyl sulfide measuring device as described in Patent Document 1 is used in a semiconductor factory, the catalytic reaction of carbonyl sulfide is stable in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent are present. There is a problem that it needs to be done.

The present invention has been made to solve the above problems, and one object of the present invention is an environment in which volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present. Also, it is an object of the present invention to provide a carbonyl sulfide decomposition device and a carbonyl sulfide detection device capable of stably performing a catalytic reaction of carbonyl sulfide.

As a result of diligent studies to achieve the above object, the inventor of the present application found that the catalyst containing alkaline earth metal silicate is resistant to poisoning of volatile components such as fluorine-based refrigerants and cleaning agents often used in semiconductor factories. I got a new finding. That is, the carbonyl sulfide decomposition apparatus according to the first aspect of the present invention includes a catalyst portion having a catalyst for catalytic reaction of carbonyl sulfide including at least hydrolysis, and a heating mechanism for inducing a catalytic reaction. Includes alkaline earth metal silicates.

In the carbonyl sulfide decomposition apparatus according to the first aspect of the present invention, the catalyst is configured to contain an alkaline earth metal silicate as described above. As a result, even in an environment where volatile components such as fluorine-based refrigerants and cleaning agents, which are often used in semiconductor factories, are present due to catalysts containing alkaline earth metal silicates, they are covered by volatile components such as fluorine-based refrigerants and cleaning agents. It can trigger a catalytic reaction of carbonyl sulfide while suppressing poisoning. As a result, it is possible to provide a carbonyl sulfide decomposition apparatus capable of stably performing a catalytic reaction of carbonyl sulfide even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present. Can be done.

In the carbonyl sulfide decomposition apparatus according to the first aspect, the catalyst preferably contains silica, magnesium, and calcium as alkaline earth metal silicates. With this configuration, the catalyst containing silica, magnesium, and calcium causes a catalytic reaction of carbonyl sulfide even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present. Can be stably triggered.

In this case, preferably, the catalyst further comprises at least one of platinum and palladium, and alumina. With this configuration, the catalytic reaction can be promoted by at least one of platinum and palladium and alumina. Therefore, a catalyst containing at least one of platinum and palladium and alumina can be used to generate carbonyl sulfide. The catalytic reaction effect can be suitably exhibited. This point has been confirmed in an experiment described later by the inventor of the present application.

In the carbonyl sulfide decomposition apparatus according to the first aspect, the catalyst preferably contains 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia and calcia in a range in which the total does not exceed 100% by mass. Including with. With this configuration, 50% by mass or more of silica (silicon dioxide: SiO ₂ ) and 10% by mass or more and 30% by mass or less of magnesia (magnesium oxide: MgO) and calcia (calcium oxide: CaO) are contained. As a result, the catalyst can be used as a basic catalyst, so that the catalytic reaction effect of carbonyl sulfide can be suitably exhibited. This point has been confirmed in an experiment described later by the inventor of the present application.

In this case, preferably, the catalyst further contains 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium, as long as the total does not exceed 100% by mass. With this configuration, the catalytic reaction can be promoted by 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium, so that 1% by mass or less of platinum, A catalyst containing 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium can preferably exert the catalytic reaction effect of carbonyl sulfide. This point has been confirmed in an experiment described later by the inventor of the present application.

In a configuration in which the catalyst contains 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia and calcia, the catalyst preferably contains 30% by mass or less of alumina, for a total of more than 100% by mass. Including further to the extent that there is no. With this configuration, the catalytic reaction can be promoted with 30% by mass or less of alumina, so that the catalytic reaction effect of carbonyl sulfide can be suitably exhibited by the catalyst containing 30% by mass or less of alumina. .. This point has been confirmed in an experiment described later by the inventor of the present application.

In the carbonyl sulfide decomposition apparatus according to the first aspect, preferably, the heating mechanism is configured to heat the catalyst portion in a temperature range of 140 ° C. or higher and 500 ° C. or lower. With this configuration, by setting the heating temperature of the heating mechanism to 140 ° C. or higher, the catalytic reaction effect of carbonyl sulfide can be suitably exhibited by the catalyst containing the alkaline earth metal silicate. Further, by setting the heating temperature of the heating mechanism to 500 ° C. or lower, it is possible to prevent the catalytic reaction effect of carbonyl sulfide from being excessively lowered due to the influence of the interference gas. This point has been confirmed in an experiment described later by the inventor of the present application.

In the carbonyl sulfide decomposition apparatus according to the first aspect, the catalyst preferably further contains 11% by mass or less of platinum or 10% by mass or less of palladium in a range not exceeding 100% by mass in total. With this configuration, the catalytic reaction can be promoted with 11% by mass or less of platinum or 10% by mass or less of palladium. Therefore, 11% by mass or less of platinum or 10% by mass or less of palladium can be used. Depending on the catalyst contained, the catalytic reaction effect of carbonyl sulfide can be suitably exhibited. This point has been confirmed in an experiment described later by the inventor of the present application.

The carbonyl sulfide detector according to the second aspect of the present invention is detected by a carbonyl sulfide decomposition part for catalytic reaction of carbonyl sulfide including at least hydrolysis and a carbonyl sulfide decomposition part generated by catalytic reaction of carbonyl sulfide by the carbonyl sulfide decomposition part. The carbonyl sulfide decomposition unit includes a gas detection unit for detecting components in the gas, a catalyst unit having a catalyst for catalytic reaction of carbonyl sulfide including at least hydrolysis, and a heating mechanism for inducing a catalytic reaction. , And the catalyst comprises an alkaline earth metal silicate.

In the carbonyl sulfide detector according to the second aspect of the present invention, the catalyst is configured to contain an alkaline earth metal silicate as described above. As a result, the catalytic reaction of carbonyl sulfide is stabilized even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present, as in the case of the carbonyl sulfide decomposition apparatus according to the first aspect. It is possible to provide a carbonyl sulfide detection device that can be performed.

In the carbonyl sulfide detection device according to the second aspect, the gas detection unit preferably includes a gas detection unit of an electrochemical type. With this configuration, the electrochemical gas detection unit can suitably detect the components in the gas to be detected generated by the catalytic reaction of carbonyl sulfide by the carbonyl sulfide decomposition unit.

According to the present invention, as described above, the catalytic reaction of carbonyl sulfide can be stably performed even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present.

It is a schematic diagram which showed the carbonyl sulfide detection apparatus by one Embodiment. It is a graph which showed the experimental result (relationship between a COS adjustment concentration and an indicated value) by Example 1. It is a graph which showed the experimental result ( _{relationship between Al 2} O _{3 content rate and an indicated value) by Example 2. FIG.} It is a graph which showed the experimental result ( _{relationship between Pt / Al 2} O _{3 content rate and an indicated value) by Example 3. FIG.} It is a graph which showed the experimental result ( _{relationship between Pd / Al 2} O _{3 content rate and an indicated value) by Example 4. FIG.} It is a graph which showed the experimental result by Example 5 (relationship between Pt: Pd (1: 1) / Al ₂ O ₃ content rate and an indicated value). It is a graph which showed the experimental result by Example 6 (relationship between Pt: Pd (2: 1) / Al ₂ O ₃ content rate and an indicated value). It is a graph which showed the experimental result by Example 7 (relationship between Pt: Pd (1: 2) / Al ₂ O ₃ content rate and an indicated value). It is a graph which showed the experimental result (relationship between a catalyst temperature and an indicated value) by Example 8. It is a graph which showed the experimental result (relationship between a catalyst temperature and an indicated value) by Example 9. It is a graph which showed the experimental result (miscellaneous gas coherence) by Example 10. It is a graph which showed the experimental result (miscellaneous gas coexistence responsiveness) by Example 11. It is a graph which showed the experimental result (exposed to saturated vapor of miscellaneous gas) by Example 12. It is a graph which showed the experimental result (pressure loss with respect to a catalyst bulk density) by Example 13. It is a graph which showed the experimental result (relationship between a Pt content and an indicated value) by Example 14. 6 is a graph showing the experimental results (relationship between Pd content and indicated value) according to Example 15. It is a graph which showed the experimental result (miscellaneous gas coherence) by Example 16. It is a graph which showed the experimental result (miscellaneous gas coherence) by Example 17.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the configuration of the carbonyl sulfide detection device 100 according to the embodiment will be described with reference to FIG.

(Overall configuration of carbonyl sulfide detector)
As shown in FIG. 1, the carbonyl sulfide detection device 100 is a device that catalytically reacts carbonyl sulfide (chemical composition: COS) and detects components in a gas to be detected generated by the catalytic reaction of carbonyl sulfide. is there. The carbonyl sulfide detection device 100 can be used, for example, for detecting carbonyl sulfide in an analysis sample, for detecting carbonyl sulfide in an atmosphere, and the like.

The carbonyl sulfide detection device 100 includes a flow rate control unit 10, a pump 20, a carbonyl sulfide decomposition unit 30, and a gas detection unit 40. The flow rate control unit 10, the carbonyl sulfide decomposition unit 30, the gas detection unit 40, and the pump 20 are moved from the upstream side to the downstream side in the flow direction of the gas to be detected G (gas of the analysis sample, gas in the atmosphere, etc.). Toward, they are fluidly connected in this order by the gas flow path 50. The connection order of each configuration is not particularly limited as long as the carbonyl sulfide decomposition unit 30 and the gas detection unit 40 are connected in this order. Further, the carbonyl sulfide decomposition unit 30 is an example of a “carbonyl sulfide decomposition apparatus” within the scope of the claims.

The flow rate control unit 10 is, for example, a mass flow controller, and is configured to control the flow rate of the detected gas G. The carbonyl sulfide detection device 100 is configured so that a constant flow rate of the detected gas G flows by controlling the flow rate of the detected gas G by the flow rate control unit 10. The flow rate of the detected gas G is not particularly limited, but can be, for example, about 500 ml / m. The pump 20 is a drive source for assisting the built-in pump of the gas detection unit 40 when the gas to be detected G causes a pressure loss due to the carbonyl sulfide decomposition unit 30 via the gas flow path 50.

The carbonyl sulfide decomposition unit 30 is configured to cause a catalytic reaction of carbonyl sulfide in the detected gas G at least including hydrolysis. Specifically, the carbonyl sulfide decomposition unit 30 includes a catalyst cylinder 31 and a heating mechanism 32. The catalyst cylinder 31 has a cylinder body 31a and a catalyst 31b. The cylinder body 31a is, for example, an alumina tube, a quartz tube, or the like. The cylinder body 31a has a hollow cylindrical shape. The cylinder body 31a is filled with the catalyst 31b. The catalyst 31b is provided so that the carbonyl sulfide in the detected gas G undergoes a catalytic reaction including at least hydrolysis. Catalysis, for example, carbonyl sulfide as shown in formula (1) hydrolysis reaction is shown in the following equation (2), hydrogen sulfide generated by the hydrolysis of carbonyl sulfide (chemical composition: H 2 _S) in It may include an oxidation reaction and the like. The catalyst cylinder 31 is an example of the "catalyst unit" in the claims.
COS + H ₂ O → H ₂ S + CO ₂ ... (1)
H ₂ S + 3 / 2O ₂ → SO ₂ + H ₂ O ・ ・ ・ (2)

Here, in the present embodiment, the catalyst 31b contains an alkaline earth metal silicate which is a basic catalyst. The catalyst 31b is preferably a material exhibiting basicity from the viewpoint of promoting the catalytic reaction of carbonyl sulfide. For example, the catalyst 31b contains an alkaline earth metal oxide, an alkali metal oxide, a rare earth oxide, thorium (IV) oxide (chemical composition: ThO ₂ ), zirconia (chemical composition: ZrO ₂ ), zinc oxide (chemical composition:). ZnO), sepiolite (chemical _{composition: Mg 4 Si 12 O 30 (} OH) 4 (OH 2) 4 · 8H 2 O), hydrotalcite (chemical _{composition: Mg 6 Al 2 CO 3 (} OH) 16 · 4H 2 O ), Chrysotile (chemical composition: Mg ₃ (Si ₂ O ₅ ) (OH) ₄ ) and the like may be contained. Further, iron oxide may be contained as a material showing both sexes. Specifically, magnetite (chemical composition: Fe ²⁺ Fe ³⁺ ₂ O ₄ ), hematite (chemical composition: Fe ₂ O ₃ , α-Fe ₂ O ₃ ), maghemite (chemical composition: Fe ₂ O _3). , Γ-Fe ₂ O ₃ ).

Preferably, the catalyst 31b contains silica (chemical composition: SiO ₂ ), magnesium (chemical composition: Mg), and calcium (chemical composition: Ca) as an alkaline earth metal silicate. More preferably, the catalyst 31b contains alumina (chemical composition: Al ₂ O ₃ ). More preferably, the catalyst 31b contains at least one of platinum (chemical composition: Pt) and palladium (chemical composition: Pd).

More preferably, the catalyst 31b contains 40% by mass or more of silica and 10% by mass or more and 50% by mass or less of magnesia (chemical composition: MgO) and calcia (chemical composition: CaO) in a total amount of more than 100% by mass. It is included in the range that does not exist. More preferably, the catalyst 31b contains 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia (chemical composition: MgO) and calcia (chemical composition: CaO) in a total amount of more than 100% by mass. It is included in the range that does not exist. More preferably, the catalyst 31b contains 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium in a range not exceeding 100% by mass in total. More preferably, the catalyst 31b contains 30% by mass or less of alumina in a range not exceeding 100% by mass in total. Further, preferably, the catalyst 31b contains 11% by mass or less of platinum or 10% by mass or less of palladium without containing alumina in a range not exceeding 100% by mass in total. The decomposition experiment of carbonyl sulfide by the catalyst 31b containing an alkaline earth metal silicate will be described later.

Further, the catalyst 31b is formed in a cotton-like shape made of inorganic fibers. The catalyst 31b has an average fiber diameter of 2 μm or more and 4 μm or less. The cotton-like catalyst 31b is filled in the cylinder body 31a of the catalyst cylinder 31. The bulk density of the filled catalyst 31b is not particularly limited, but can be, for example, 70 kg / m ³ or more and 250 kg / m ³ or less from the viewpoint of reducing pressure loss. The cotton-like catalyst 31b is provided so as to form a filling layer on the cylinder body 31a of the catalyst cylinder 31. The packed layer of the catalyst 31b is held inside the cylinder body 31a of the catalyst cylinder 31 by the holding members 31c of the catalyst 31b arranged at both ends. The holding member 31c is, for example, quartz wool. The holding member 31c is a member for holding the catalyst 31b, and is not limited as long as it is a material that can withstand the temperature of the heating mechanism 32.

The heating mechanism 32 is configured to heat the catalyst cylinder 31 in order to cause a catalytic reaction. Specifically, the heating mechanism 32 includes a heating unit 32a and a heat insulating unit 32b. The heating unit 32a is configured to heat the catalyst 31b via the cylinder body 31a of the catalyst cylinder 31. The heating unit 32a is, for example, a heating wire. The heating portion 32a, which is a heating wire, is formed in a coil shape so as to surround the catalyst 31b with the cylinder body 31a of the catalyst cylinder 31 separated from the heating portion 32a, for example. The shape of the heating wire is not limited as long as the temperature of the heating mechanism 32 can be kept constant. The heating portion 32a is provided so as to face the packed layer of the catalyst 31b from one end to the other end of the packed layer of the catalyst 31b. That is, the heating unit 32a is configured to heat the catalyst 31b from one end to the other end of the packed bed of the catalyst 31b. The heat insulating portion 32b is made of a heat insulating material, and is provided so as to surround the heating portion 32a and the catalyst 31b of the catalyst cylinder 31. The heat insulating material of the heat insulating portion 32b is, for example, a biosoluble fiber heat insulating material.

The heating mechanism 32 is preferably configured to heat the catalyst cylinder 31 by the heating unit 32a in a temperature range of 140 ° C. or higher and 500 ° C. or lower. More preferably, the heating mechanism 32 is configured to heat the catalyst cylinder 31 by the heating unit 32a in a temperature range of 260 ° C. or higher and 500 ° C. or lower. More preferably, the heating mechanism 32 is configured to heat the catalyst cylinder 31 by the heating unit 32a in a temperature range of 280 ° C. or higher and 400 ° C. or lower. Further, the heating mechanism 32 is configured to heat the catalyst cylinder 31 by the heating unit 32a so that the temperature becomes substantially constant. Heating such that the catalyst cylinder 31 reaches a substantially constant temperature is not particularly limited, but for example, based on the temperature detection result by a temperature detection unit (not shown), the heating unit of the heating mechanism 32 is subjected to feedback control such as PID control. This can be done by controlling 32a.

The gas detection unit 40 is configured to detect components (hydrogen sulfide, sulfur oxide, etc.) in the gas to be detected G generated by the catalytic reaction of carbonyl sulfide by the carbonyl sulfide decomposition unit 30. The gas detection unit 40 includes an electrochemical gas detection unit (electrochemical type sensor). Specifically, the gas detection unit 40 includes a constant-potential electrolysis type gas detection unit (constant-potential electrolysis type sensor) suitable for detecting hydrogen sulfide, sulfur oxides, and the like. The carbonyl sulfide detection device 100 indirectly detects carbonyl sulfide by detecting components (hydrogen sulfide, sulfur oxide, etc.) in the detected gas G generated by the catalytic reaction of carbonyl sulfide by the gas detection unit 40. It is configured to detect. The gas detection unit 40 is configured to incorporate a pump for flowing the gas to be detected G.

(Effect of this embodiment)
In this embodiment, the following effects can be obtained.

In the present embodiment, as described above, the catalyst 31b is configured to contain an alkaline earth metal silicate. As a result, even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present due to the catalyst 31b containing an alkaline earth metal silicate, the volatile components such as a fluorine-based refrigerant and a cleaning agent are used. It can trigger a catalytic reaction of carbonyl sulfide while suppressing poisoning. As a result, the catalytic reaction of carbonyl sulfide can be stably performed even in an environment where volatile components such as a fluorine-based refrigerant and a cleaning agent, which are often used in semiconductor factories, are present.

Further, in the present embodiment, as described above, the catalyst 31b contains silica, magnesium, and calcium as alkaline earth metal silicates. As a result, the catalyst 31b containing silica, magnesium, and calcium can stably induce a catalytic reaction of carbonyl sulfide even in an environment in which volatile components such as a fluorine-based refrigerant and a cleaning agent are present.

Further, in the present embodiment, as described above, the catalyst 31b is configured to contain at least one of platinum and palladium and alumina. As a result, the catalytic reaction can be promoted by at least one of platinum and palladium and alumina. Therefore, the catalytic reaction effect of carbonyl sulfide by the catalyst 31b containing at least one of platinum and palladium and alumina. Can be suitably exhibited. This point has been confirmed in an experiment described later by the inventor of the present application.

Further, in the present embodiment, as described above, the catalyst 31b contains 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia and calcia within a range in which the total does not exceed 100% by mass. It is configured as follows. As a result, the catalyst 31b can be used as a basic catalyst by containing 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia and calcia, so that the catalytic reaction effect of carbonyl sulfide is preferable. Can be demonstrated. This point has been confirmed in an experiment described later by the inventor of the present application.

Further, in the present embodiment, as described above, the total amount of the catalyst 31b containing 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium does not exceed 100% by mass. Configure to include in the range. As a result, the catalytic reaction can be promoted by 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium, so that 1% by mass or less of platinum and 2% by mass or less of palladium can be promoted. The catalytic reaction effect of carbonyl sulfide can be suitably exhibited by the catalyst 31b containing palladium or 2% by mass or less of platinum and palladium. This point has been confirmed in an experiment described later by the inventor of the present application.

Further, in the present embodiment, as described above, the catalyst 31b is configured to contain 30% by mass or less of alumina in a range not exceeding 100% by mass in total. As a result, the catalytic reaction can be promoted with 30% by mass or less of alumina, so that the catalytic reaction effect of carbonyl sulfide can be suitably exhibited by the catalyst 31b containing 30% by mass or less of alumina. This point has been confirmed in an experiment described later by the inventor of the present application.

Further, in the present embodiment, as described above, the heating mechanism 32 is configured to heat the catalyst 31b in a temperature range of 140 ° C. or higher and 500 ° C. or lower. As a result, by setting the heating temperature of the heating mechanism 32 to 140 ° C. or higher, the catalytic reaction effect of carbonyl sulfide can be suitably exhibited by the catalyst 31b containing the alkaline earth metal silicate. Further, by setting the heating temperature of the heating mechanism 32 to 500 ° C. or lower, it is possible to prevent the catalytic reaction effect of carbonyl sulfide from being excessively lowered due to the influence of the interference gas. This point has been confirmed in an experiment described later by the inventor of the present application.

Further, in the present embodiment, as described above, the catalyst 31b is configured to contain 11% by mass or less of platinum or 10% by mass or less of palladium in a range not exceeding 100% by mass in total. As a result, the catalytic reaction can be promoted with 11% by mass or less of platinum or 10% by mass or less of palladium. Therefore, the catalyst 31b containing 11% by mass or less of platinum or 10% by mass or less of palladium can be used. , The catalytic reaction effect of carbonyl sulfide can be suitably exhibited. This point has been confirmed in an experiment described later by the inventor of the present application.

[Example]
Next, a confirmation experiment (Examples 1 to 13) performed to confirm the effect of the present invention will be described with reference to FIGS. 2 to 18.

(Example 1)
As shown in FIG. 2, in this confirmation experiment, the detected gas G containing 5 ppm, 10 ppm, 15 ppm, and 20 ppm of carbonyl sulfide was used in the carbonyl sulfide detector (Example 1) using a catalyst containing an alkaline earth metal silicate. Was detected, and an indicated value (a value corresponding to the output value of the gas detection unit according to the detected amount) was obtained.

As the carbonyl sulfide detection device of Example 1, the carbonyl sulfide detection device 100 shown in FIG. 1 was used. In the carbonyl sulfide detection device of Example 1, a tube having an outer cylinder and an inner cylinder was used as the cylinder body 31a. As the outer cylinder, an alumina tube having an inner diameter of 12.9 mm was used, and as the inner cylinder, a quartz tube having an inner diameter of 8.3 mm was used. Further, as the catalyst 31b, 73.4% by mass of SiO ₂ (silica), 19.1% by mass of MgO (magnesia) and CaO (calcia), 0.2% by mass of Pt (platinum), and 4. A catalyst containing 4% by mass of Al ₂ O ₃ and 2.9% by mass of other components was used.

The catalyst 31b was prepared as follows. First, an alkaline earth metal silicate was prepared. As the alkaline earth metal silicate, "Isoool BSSR 1300 Bulk" manufactured by Isolite Industries, Ltd. was used. In this case, the produced catalyst 31b may contain crystals of urastonite, diopside or enstatite, or K ₂ O, Na ₂ O, Fe ₂ O ₃ , ZrO ₂ , P ₂ O ₄ , It _{may contain Ba 2} O ₃ , La ₂ O ₃ , and the like. Then, the prepared alkaline earth metal silicate was immersed in a viscous solvent in which alumina supporting platinum was dispersed. Then, the alkaline earth metal silicate immersed in the viscous solvent was taken out from the viscous solvent and fired. As a result, _{a catalyst 31b containing SiO 2} , MgO and CaO, Pt, Al ₂ O ₃ and other components at the above-mentioned contents was produced. Further, as the gas detection unit 40, PS-7 (model number) of New Cosmos Electric Co., Ltd., which includes a constant potential electrolysis type gas detection unit, was used.

In the carbonyl sulfide detector of Example 1, the gas to be detected G containing 5 ppm, 10 ppm, 15 ppm, and 20 ppm of carbonyl sulfide was flowed, respectively, and the indicated value of the gas detection unit was obtained. The graph on the left side shown in FIG. 2 shows the time change of the indicated value of the gas detection unit in each detected gas G. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 2 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the COS adjusted concentration. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the COS adjustment concentration.

As can be seen from the graph shown in FIG. 2, in the carbonyl sulfide detection device of Example 1, there is a correlation between the COS adjustment concentration and the indicated value of the gas detection unit in the range of 5 ppm or more and 20 ppm or less of the COS adjustment concentration. It was seen. Specifically, in the carbonyl sulfide detector of Example 1, the relationship between the COS adjusted concentration and the indicated value of the gas detection unit could be linearly approximated in the range of 5 ppm or more and 20 ppm or less of the COS adjusted concentration. .. From this, it is considered that the COS concentration can be accurately measured from the indicated value of the gas detection unit. Further, it is considered that a catalyst containing an alkaline earth metal silicate can be suitably used for measuring the concentration of COS.

(Example 2)
_{As shown in FIG. 3, in this confirmation experiment, the influence of the Al 2} O ₃ content was investigated by a carbonyl sulfide detector (Example 2) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 2, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 1 below was used.

In the carbonyl sulfide detector of Example 2, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 3 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 3 shows the relationship between the indicated value in the graph on the left side at a predetermined time point and the Al ₂ O _{3 content rate.} In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Al ₂ O ₃ content rate.

As can be seen from the graph shown in FIG. 3, in the carbonyl sulfide detector of Example 2, _{the catalytic reaction of carbonyl sulfide is carried out in the range where the Al 2} O ₃ content is 1.98% by mass or more and 21.44% by mass or less. I was able to. Further, in the carbonyl sulfide detector of Example 2, in _{the range where the Al 2} O ₃ content is 1.98% by mass or more and 13.67% by mass or less, as the Al ₂ O ₃ content increases, the gas detection unit The indicated value tended to increase. Further, in the carbonyl sulfide detector of Example 2, the gas detector reading value tended to be almost flat in the range of the _{Al 2} O _{3 content of 13.67% by mass or more and 21.44% by mass or less.} From this, it _{is considered that in the range where the Al 2} O ₃ content is 1.98% by mass or more and 21.44% by mass or less, the _{larger the Al 2} O ₃ content is, the more preferably it can be used as a catalyst. Specifically, it is considered that the Al ₂ O ₃ content is preferably in the range of 13.67% by mass or more and 21.44% by mass or less.

(Example 3)
_{As shown in FIG. 4, in this confirmation experiment, the influence of the Pt and Al 2} O ₃ contents was investigated by a carbonyl sulfide detector (Example 3) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 3, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 2 below was used.

In the carbonyl sulfide detector of Example 3, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 4 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 4 shows the relationship between the indicated value of the graph on the left side at a predetermined time point and the Pt and Al ₂ O _{3 contents.} In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pt and Al ₂ O ₃ contents.

As can be seen from the graph shown in FIG. 4, in the carbonyl sulfide detector of Example 3, the Pt content is 0.11% by mass or more and 0.92% by mass or less, and the Al ₂ O ₃ content is 2.03% by mass. The catalytic reaction of carbonyl sulfide could be carried out in the range of 17.39% by mass or less. Further, the carbonyl sulfide detection device of Example 3, with Pt content of less 0.23 mass% or more 0.92 wt%, _Al 2 _{O 3} content is less 17.39 mass% or more 4.43 wt% In the range, as the Pt content and the Al ₂ O ₃ content decreased, the indicated value of the gas detection unit tended to increase. Further, the carbonyl sulfide detection device of Example 3, Pt content is not more than 0.11 mass% to 0.23 mass%, _Al 2 _{O 3} content is less 4.43 wt% or more 2.03 wt% In the range, the indicated value of the gas detector tended to be almost flat. From this, in the range where the Pt content is 0.11% by mass or more and 0.92% by mass or less and the Al ₂ O ₃ content is 2.03% by mass or more and 17.39% by mass or less, the Pt content and Al about ₂ O ₃ content is low, is believed can be suitably used as a catalyst. Specifically, it is preferable that the Pt content is 0.11% by mass or more and 0.23% by mass or less, and the Al ₂ O ₃ content is 2.03% by mass or more and 4.43% by mass or less. Conceivable.

Further, the carbonyl sulfide detection device of the third embodiment, and schematically, Pt content is not more than 0.57 mass% to 0.11 mass%, _Al 2 _{O 3} content is more than 2.03 mass% 10. In the range of 88% by mass or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. It is considered that this is because the catalytic reaction of carbonyl sulfide was promoted because the oxidation reaction represented by the above formula (2) was promoted by Pt contained in the catalyst.

(Example 4)
_{As shown in FIG. 5, in this confirmation experiment, the influence of the Pd and Al 2} O ₃ contents was investigated by a carbonyl sulfide detector (Example 4) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 4, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 3 below was used.

In the carbonyl sulfide detector of Example 4, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 5 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 5 shows the relationship between the indicated value in the graph on the left side at a predetermined time point and the Pd and Al ₂ O _{3 contents.} In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pd and Al ₂ O ₃ contents.

As can be seen from the graph shown in FIG. 5, in the carbonyl sulfide detector of Example 4, the Pd content is 0.11% by mass or more and 1.74% by mass or less, and the Al ₂ O ₃ content is 1.02% by mass. The catalytic reaction of carbonyl sulfide could be carried out in the range of 15.67% by mass or less. Further, the carbonyl sulfide detection device of Example 4, Pd content is not more than 1.00 mass% to 0.11 mass%, _Al 2 _{O 3} content is less 9.03 wt% or more 1.02 wt% In the range, as the Pd content and the Al ₂ O ₃ content increased, the indicated value of the gas detection unit tended to increase. Further, the carbonyl sulfide detection device of Example 4, Pd content is not more than 1.38 wt% 1.00 wt% or more, _Al 2 _{O 3} content is less 15.67 mass% or more 9.03 wt% In the range, as the Pd content and the Al ₂ O ₃ content increased, the indicated value of the gas detection unit tended to decrease. From this, in the range where the Pd content is 0.11% by mass or more and 1.74% by mass or less and the Al ₂ O ₃ content is 1.02% by mass or more and 15.67% by mass or less, the Pd content is 1. It is considered that the closer the Al ₂ O ₃ content is to 9.03% by mass at 0.000% by mass, the more preferably it can be used as a catalyst. Specifically, Pd content is not more than 1.38 mass% to 0.76 mass%, and is preferably _Al 2 _{O 3} content is in the range of less 12.44 mass% or more 6.87 wt% Conceivable.

Further, the carbonyl sulfide detection device of Example 4, the schematic, Pd content is not more than 0.41 mass% to 1.74 mass%, _Al 2 _{O 3} content is 3.71 mass% or more 15. In the range of 67% by mass or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. It is considered that this is because the catalytic reaction of carbonyl sulfide was promoted due to the promotion of the oxidation reaction represented by the above formula (2) by Pd contained in the catalyst.

(Example 5)
_{As shown in FIG. 6, in this confirmation experiment, the influence of the Pt, Pd and Al 2} O ₃ contents was investigated by a carbonyl sulfide detector (Example 5) using a catalyst containing an alkaline earth metal silicate. The Pt content and the Pd content were set to 1: 1. As the carbonyl sulfide detection device of Example 5, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 4 below was used.

In the carbonyl sulfide detector of Example 5, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 6 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 6 shows the relationship between the _{indicated value of the graph on the left side at a predetermined time point and the content of Pt, Pd and Al 2} O _3. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pt, Pd and Al ₂ O ₃ contents.

As can be seen from the graph shown in FIG. 6, in the carbonyl sulfide detector of Example 5, the Pt content is 0.11% by mass or more and 0.74% by mass or less, and the Pd content is 0.09% by mass or more and 0. The catalytic reaction of carbonyl sulfide could be carried out in the range of 67% by mass or less and the Al ₂ O ₃ content of 2.83% by mass or more and 20.09% by mass or less. Further, in the carbonyl sulfide detector of Example 5, the Pt content is 0.11% by mass or more and 0.44% by mass or less, the Pd content is 0.09% by mass or more and 0.45% by mass or less, and Al ₂ In _{the range where the O 3} content is 2.83% by mass or more and 12.33% by mass or less, the indicated value of the gas detector tends to decrease as the _{Pt content, Pd content and Al 2} O _{3 content increase.} showed that. Further, in the carbonyl sulfide detector of Example 5, the Pt content is 0.44% by mass or more and 0.74% by mass or less, the Pd content is 0.45% by mass or more and 0.67% by mass or less, and Al ₂ O ₃ content in the range of 12.33 wt% or more 20.09 wt%, showed a tendency indicated value of the gas sensing portion is flat. From this, the Pt content is 0.11% by mass or more and 0.74% by mass or less, the Pd content is 0.09% by mass or more and 0.67% by mass or less, and the Al ₂ O ₃ content is 2.83. In the range of mass% or more and 20.09% by mass or less, it is _{considered that the smaller the Pt content, the Pd content and the Al 2} O ₃ content, the more preferably it can be used as a catalyst. Specifically, the Pt content is 0.11% by mass or more and 0.29% by mass or less, the Pd content is 0.09% by mass or more and 0.29% by mass or less, and the Al ₂ O ₃ content is 2. It is considered that the range is preferably 83% by mass or more and 8.08% by mass or less.

Further, in the carbonyl sulfide detector of Example 5, the Pt content is roughly 0.11% by mass or more and 0.37% by mass or less, and the Pd content is 0.09% by mass or more and 0.39% by mass. Below, in the range where the Al ₂ O ₃ content was 2.83% by mass or more and 12.33% by mass or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. It is considered that this is because the catalytic reaction of carbonyl sulfide was promoted due to the promotion of the oxidation reaction represented by the above formula (2) by Pt and Pd contained in the catalyst.

(Example 6)
_{As shown in FIG. 7, in this confirmation experiment, the influence of the Pt, Pd and Al 2} O ₃ contents was investigated by a carbonyl sulfide detector (Example 6) using a catalyst containing an alkaline earth metal silicate. The Pt content and the Pd content were set to 2: 1. As the carbonyl sulfide detection device of Example 6, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 5 below was used.

In the carbonyl sulfide detector of Example 7, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 7 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 7 shows the relationship between the _{indicated value of the graph on the left side at a predetermined time point and the content of Pt, Pd and Al 2} O _3. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pt, Pd and Al ₂ O ₃ contents.

As can be seen from the graph shown in FIG. 7, in the carbonyl sulfide detector of Example 6, the Pt content is 0.10% by mass or more and 0.69% by mass or less, and the Pd content is 0.05% by mass or more and 0. The catalytic reaction of carbonyl sulfide could be carried out in the range of 37% by mass or less and the Al ₂ O ₃ content of 2.35% by mass or more and 16.50% by mass or less. Further, in the carbonyl sulfide detector of Example 6, the Pt content is 0.10% by mass or more and 0.47% by mass or less, the Pd content is 0.05% by mass or more and 0.25% by mass or less, and Al ₂ In _{the range where the O 3} content is 2.35% by mass or more and 11.14% by mass or less, the indicated value of the gas detector tends to decrease as the _{Pt content, Pd content and Al 2} O _{3 content increase.} showed that. Further, in the carbonyl sulfide detector of Example 6, the Pt content is 0.47% by mass or more and 0.69% by mass or less, the Pd content is 0.25% by mass or more and 0.37% by mass or less, and Al ₂ O ₃ content in the range of 11.14 wt% or more 16.50 wt%, showed a tendency indicated value of the gas sensing portion is flat. From this, the Pt content is 0.10% by mass or more and 0.69% by mass or less, the Pd content is 0.05% by mass or more and 0.37% by mass or less, and the Al ₂ O ₃ content is 2.35. In the range of mass% or more and 16.50 mass% or less, it is _{considered that the smaller the Pt content, the Pd content and the Al 2} O ₃ content, the more preferably it can be used as a catalyst. Specifically, the Pt content is 0.10% by mass or more and 0.27% by mass or less, the Pd content is 0.05% by mass or more and 0.16% by mass or less, and the Al ₂ O ₃ content is 2. It is considered that the range is preferably 35% by mass or more and 6.63% by mass or less.

Further, in the carbonyl sulfide detector of Example 6, the Pt content is roughly 0.10% by mass or more and 0.37% by mass or less, and the Pd content is 0.05% by mass or more and 0.20% by mass. Below, in the range where the Al ₂ O ₃ content was 2.35% by mass or more and 8.92% by mass or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. It is considered that this is because the catalytic reaction of carbonyl sulfide was promoted due to the promotion of the oxidation reaction represented by the above formula (2) by Pt and Pd contained in the catalyst.

(Example 7)
_{As shown in FIG. 8, in this confirmation experiment, the influence of the Pt, Pd and Al 2} O ₃ contents was investigated by a carbonyl sulfide detector (Example 7) using a catalyst containing an alkaline earth metal silicate. The Pt content and the Pd content were set to be 1: 2. As the carbonyl sulfide detection device of Example 7, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 6 below was used.

In the carbonyl sulfide detector of Example 7, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 8 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 8 shows the relationship between the _{indicated value of the graph on the left side at a predetermined time point and the content of Pt, Pd and Al 2} O _3. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pt, Pd and Al ₂ O ₃ contents.

As can be seen from the graph shown in FIG. 8, in the carbonyl sulfide detector of Example 7, the Pt content is 0.05% by mass or more and 0.46% by mass or less, and the Pd content is 0.13% by mass or more and 0. The catalytic reaction of carbonyl sulfide could be carried out in a range of 85% by mass or less and an Al ₂ O ₃ content of 2.04% by mass or more and 16.36% by mass or less. Further, in the carbonyl sulfide detector of Example 7, the Pt content is 0.05% by mass or more and 0.46% by mass or less, the Pd content is 0.13% by mass or more and 0.85% by mass or less, and Al ₂ In _{the range where the O 3} content is 2.04% by mass or more and 16.36% by mass or less, the indicated value of the gas detector tends to decrease as the _{Pt content, Pd content and Al 2} O _{3 content increase.} showed that. From this, the Pt content is 0.05% by mass or more and 0.46% by mass or less, the Pd content is 0.13% by mass or more and 0.85% by mass or less, and the Al ₂ O ₃ content is 2.04. In the range of mass% or more and 16.36% by mass or less, it is _{considered that the smaller the Pt content, the Pd content and the Al 2} O ₃ content, the more preferably it can be used as a catalyst. Specifically, the Pt content is 0.05% by mass or more and 0.20% by mass or less, the Pd content is 0.13% by mass or more and 0.37% by mass or less, and the Al ₂ O ₃ content is 2. It is considered that the range is preferably 04% by mass or more and 7.20% by mass or less.

Further, in the carbonyl sulfide detector of Example 7, the Pt content is roughly 0.05% by mass or more and 0.20% by mass or less, and the Pd content is 0.13% by mass or more and 0.37% by mass. Below, in the range where the Al ₂ O ₃ content was 2.04% by mass or more and 7.20% by mass or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. It is considered that this is because the catalytic reaction of carbonyl sulfide was promoted due to the promotion of the oxidation reaction represented by the above formula (2) by Pt and Pd contained in the catalyst.

As can be seen from Examples 2 to 7, the catalyst can further promote the catalytic reaction of carbonyl sulfide by containing at least one of Pt and Pd in addition to alumina.

(Example 8)
As shown in FIG. 9, in this confirmation experiment, the influence of the catalyst temperature (heating temperature) was investigated by a carbonyl sulfide detector (Example 8) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 8, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 7 below was used.

In the carbonyl sulfide detector of Example 8, the gas to be detected G containing 20 ppm of carbonyl sulfide was flown, and the indicated value of the gas detection unit by each catalyst at each temperature was obtained. The graph shown in FIG. 9 shows the temperature change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value (normalized value) of the gas detection unit, and the horizontal axis shows the catalyst temperature (heating temperature).

As can be seen from the graph shown in FIG. 9, the carbonyl sulfide detector of Example 8 was able to carry out a catalytic reaction of carbonyl sulfide in a temperature range of 200 ° C. or higher and 500 ° C. or lower. In addition, the carbonyl sulfide detector of Example 8 showed a substantially similar temperature tendency regardless of the catalyst. Specifically, from 280 ° C. to 330 ° C., the indicated value of the gas detection unit tended to increase as the catalyst temperature increased. Further, after 280 ° C. to 330 ° C., the indicated value of the gas detection unit tended to decrease as the catalyst temperature increased. From this, it is considered that in the range of 200 ° C. or higher and 500 ° C. or lower, the closer the catalyst temperature is to 280 ° C. to 330 ° C., the more suitable the catalyst can be used.

When the catalyst temperature is higher than 500 ° C., the influence of the interference gas described later becomes too large. Therefore, it is considered that the catalyst temperature is preferably 500 ° C. or lower. Further, when the catalyst temperature is smaller than 200 ° C., the indicated value of the gas detection unit becomes too small, so that it is considered preferable that the catalyst temperature is 200 ° C. or higher. Further, since the value is about twice or more the indicated value of the gas detection unit when the catalyst temperature is 200 ° C., it is considered more preferable that the catalyst temperature is in the range of 260 ° C. or higher and 500 ° C. or lower. Further, since the catalyst temperature is about 3 times or more the indicated value of the gas detection unit when the catalyst temperature is 200 ° C., it is considered more preferable that the catalyst temperature is in the range of 280 ° C. or higher and 400 ° C. or lower.

(Example 9)
As shown in FIG. 10, in this confirmation experiment, the influence of the catalyst temperature (heating temperature) was investigated by a carbonyl sulfide detector (Example 9) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 9, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, a catalyst containing 98.4% by mass of sepiolite, 0.08% by mass of Pt, and 1.52% by mass of Al ₂ O ₃ was used. Specifically, as a catalyst 31b, a SiO ₂ of 55.1 wt%, and 22.63 wt% of MgO, and CaO of 3.94 weight%, and _Fe 2 _{O 3} 2.95 wt%, 2 .51% by mass of Al ₂ O ₃ , 0.08% by mass of Pt, and 12.79% by mass of Ig. A catalyst containing Loss (Ignition weight loss) was used.

In the carbonyl sulfide detector of Example 9, the gas to be detected G containing 10 ppm of carbonyl sulfide was flown, and the indicated value of the gas detection unit by each catalyst at each temperature was obtained. The graph shown in FIG. 10 shows the temperature change of the indicated value of the gas detection unit. In this graph, the vertical axis shows the indicated value (normalized value) of the gas detection unit, and the horizontal axis shows the catalyst temperature (heating temperature).

As can be seen from the graph shown in FIG. 10, the carbonyl sulfide detector of Example 9 was able to carry out a catalytic reaction of carbonyl sulfide in a temperature range of 140 ° C. or higher and 400 ° C. or lower. Further, in the carbonyl sulfide detector of Example 9, up to 260 ° C., the indicated value of the gas detection unit tended to increase as the catalyst temperature increased. Further, after 260 ° C., the indicated value of the gas detection unit tended to decrease as the catalyst temperature increased. From this, it is considered that in the range of 140 ° C. or higher and 400 ° C. or lower, the closer the catalyst temperature is to 260 ° C., the more suitable the catalyst can be used.

In the carbonyl sulfide detector of Example 9, when the catalyst temperature is smaller than 140 ° C., the indicated value of the gas detection unit becomes too small, so that the catalyst temperature is preferably 140 ° C. or higher. Further, it is considered more preferable that the catalyst temperature is in the range of 160 ° C. or higher and 400 ° C. or lower as the catalyst temperature that is about twice or more the indicated value of the gas detection unit when the catalyst temperature is 140 ° C.

(Example 10)
As shown in FIG. 11, in this confirmation experiment, the influence of miscellaneous gas (interference gas) was investigated by a carbonyl sulfide detector (Example 10) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 10, the same device as the carbonyl sulfide detection device of Example 1 was used. As miscellaneous gases, a detected gas G containing 329 ppm of HT-70, a detected gas G containing 223 ppm of FC-43, a detected gas G containing 245 ppm of HFE-7100, and a subject containing 109 ppm of acetone. A detection gas G and a detection gas G containing 141 ppm of ethanol were used. Here, carbonyl sulfide is used as a dry etching gas in the semiconductor manufacturing process, and alcohols (ethanol) and ketones (acetone) are used as cleaning agents in the semiconductor manufacturing process, such as HT-70 (Garden) and FC-43 (Florinate). And HFE-7100 (Novec) is a component used as a fluorine-based inert refrigerant for chillers in the semiconductor manufacturing process. That is, in Example 10, the influence of miscellaneous gas used in the semiconductor manufacturing process was investigated on the assumption that a carbonyl sulfide detecting device is used for detecting carbonyl sulfide in the atmosphere of the semiconductor manufacturing process.

In the carbonyl sulfide detector of Example 10, the detected gas G containing 5 ppm carbonyl sulfide G, the detected gas G containing 329 ppm HT-70, the detected gas G containing 223 ppm FC-43, and the 245 ppm HFE-7100. The detected gas G containing 109 ppm of acetone, the detected gas G containing 141 ppm of ethanol, and the detected gas G containing 141 ppm of ethanol were flown to obtain the indicated value of the gas detection unit by each gas. The graph shown in FIG. 11 shows the time change of the indicated value of the gas detection unit depending on each gas. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time.

As can be seen from the graph shown in FIG. 11, in the carbonyl sulfide detector of Example 10, the indicated value of the detected gas G containing COS is about 5 ppm, whereas the detected value of the detected gas G containing HT-70 is about 5 ppm. The indicated value is about 0.1 ppm, the indicated value of the detected gas G containing FC-43 is about 0.1 ppm, the indicated value of the detected gas G including HFE-7100 is about 0.2 ppm, and the indicated gas containing acetone is about 0.2 ppm. The indicated value of G was about 0.5 ppm, and the indicated value of the detected gas G containing ethanol was about 0.6 ppm. That is, all of HT-70, FC-43, HFE-7100, acetone and ethanol showed values in which the indicated value of the gas detection unit was sufficiently smaller than that of COS. From this, it is considered that when a catalyst containing an alkaline earth metal silicate is used, none of HT-70, FC-43, HFE-7100, acetone and ethanol interferes with the detection of COS. That is, it is considered that a catalyst containing an alkaline earth metal silicate can be suitably used for detecting carbonyl sulfide in the semiconductor manufacturing process.

(Example 11)
As shown in FIG. 12, in this confirmation experiment, the response in an environment where COS and miscellaneous gas (interfering gas) coexist by the carbonyl sulfide detector (Example 11) using a catalyst containing an alkaline earth metal silicate. I checked the sex. As the carbonyl sulfide detection device of Example 11, the same device as the carbonyl sulfide detection device of Example 1 was used. As the miscellaneous gas, a detected gas G containing 329 ppm of HT-70, a detected gas G containing 223 ppm of FC-43, and a detected gas G containing 245 ppm of HFE-7100 were used.

In the carbonyl sulfide detector of Example 11, the detected gas G containing 5 ppm carbonyl sulfide, 329 ppm HT-70, 223 ppm FC-43, and 245 ppm HFE-7100 are detected. Gas G (4 gas coexisting gas) was allowed to flow, and the indicated value of the gas detection unit for each gas was obtained. The graph shown in FIG. 12 shows the time change of the indicated value of the gas detection unit depending on each gas. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time.

As can be seen from the graph shown in FIG. 12, in the carbonyl sulfide detector of Example 11, the indicated value of the detected gas G containing 5 ppm of COS is about 5.4 ppm, whereas the indicated value of the four gas coexisting gas is indicated. The value was about 5.7 ppm. That is, the indicated values of the gas detection unit showed the same values for both the gas to be detected G containing 5 ppm of COS and the gas coexisting with 4 gases. From this, it is considered that when a catalyst containing an alkaline earth metal silicate is used, the responsiveness of COS detection is hardly affected even in the coexistence of HT-70, FC-43, and HFE-7100. That is, it is considered that a catalyst containing an alkaline earth metal silicate can be suitably used for detecting carbonyl sulfide in the semiconductor manufacturing process.

(Example 12)
As shown in FIG. 13, in this confirmation experiment, deterioration of the catalyst due to saturated vapor of miscellaneous gas (interference gas) was investigated by a carbonyl sulfide detector (Example 12) using a catalyst containing an alkaline earth metal silicate. .. As the carbonyl sulfide detection device of Example 12, the same device as the carbonyl sulfide detection device of Example 1 was used. Examples of miscellaneous gases include a detected gas G containing 18.5 vol% HT-70, a detected gas G containing 1895 ppm FC-43, and a detected gas G containing 27.6 vol% HFE-7100. A Gus G to be detected containing 5.8 vol% ethanol and a Gus G to be detected containing 24.4 vol% acetone were used. In addition, 18.5 vol% HT-70, 1895 ppm FC-43, 27.6 vol% HFE-7100, 5.8 vol% ethanol, and 24.4 vol% acetone are all normal. It is a gas with a high concentration that is unthinkable in the semiconductor manufacturing process. That is, in Example 12, an accelerated test was conducted with a high-concentration gas.

In the carbonyl sulfide detector of Example 12, the detected gas G containing 18.5 vol% HT-70, the detected gas G containing 1895 ppm FC-43, and the subject containing 27.6 vol% HFE-7100. After flowing the detection gas G, the detected gas G containing 5.8 vol% ethanol, and the detected gas G containing 24.4 vol% acetone for 30 minutes each, the detected gas G containing 5 ppm COS. Was flown, and the indicated value of the gas detector was obtained. The graph shown in FIG. 13 shows the time change of the indicated value of the gas detection unit of 5 ppm of COS after 30 minutes exposure of each saturated vapor gas. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time.

As can be seen from the graph shown in FIG. 13, even after 30 minutes of exposure to each saturated vapor gas, an indicated value of about 5 ppm of the gas detection unit was obtained for 5 ppm of COS. This is because the catalyst containing the alkaline earth metal silicate did not deteriorate or deteriorated very little even when exposed to HT-70, FC-43, HFE-7100, ethanol, and acetone. it is conceivable that. From this, the catalyst containing the alkaline earth metal silicate is resistant to poisoning by the fluorine-based components HT-70, FC-43 and HFE-7100, and is also poisoned by the organic components ethanol and acetone. It is considered to be a strong catalyst.

(Example 13)
As shown in FIG. 14, in this confirmation experiment, the pressure loss with respect to the catalyst bulk density was investigated by a carbonyl sulfide detector (Example 13) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 13, the same device as the carbonyl sulfide detection device of Example 1 was used.

In the carbonyl sulfide detector of Example 13, the detected gas G was flown to obtain a pressure loss with respect to the catalyst bulk density at each temperature. The graph shown in FIG. 14 shows the change in pressure loss with respect to bulk density at each temperature. In this graph, the vertical axis shows the pressure loss and the horizontal axis shows the catalyst bulk density.

As can be seen from the graph shown in FIG. 14, the carbonyl sulfide detector of Example 13 showed a tendency for the pressure loss to increase as the catalyst bulk density increased in the temperature range of 200 ° C. or higher and 450 ° C. or lower. Further, in the carbonyl sulfide detector of Example 13, the pressure loss tended to increase as the temperature increased in the temperature range of 200 ° C. or higher and 450 ° C. or lower. Assuming that the allowable pressure loss (pressure loss that does not cause a decrease in gas flow rate) of the carbonyl sulfide detector of Example 13 is -3 kPa, the catalyst bulk density is 250 kg / m ³ or less in the temperature range of 200 ° C. or higher and 450 ° C. or lower. Is considered to be preferable. Further, from a practical point of view, it is considered that the catalyst bulk density is ^{more preferably 200 kg / m 3} or less, considering the margin. Further, from the viewpoint of securing the filling amount of the catalyst, it is considered that ^{the catalyst bulk density is preferably 70 kg / m 3 or more.}

(Example 14)
As shown in FIG. 15, in this confirmation experiment, the influence of the Pt content was investigated by a carbonyl sulfide detector (Example 14) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 14, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 8 below was used.

In the carbonyl sulfide detector of Example 14, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 15 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 15 shows the relationship between the indicated value in the graph on the left side at a predetermined time point and the Pt content rate. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pt content.

As can be seen from the graph shown in FIG. 15, in the carbonyl sulfide detector of Example 14, the catalytic reaction of carbonyl sulfide can be carried out in the range of Pt content of 0.03% by mass or more and 10.50% by mass or less. It was. Further, in the carbonyl sulfide detector of Example 14, in the range where the Pt content is 0.03% by mass or more and 0.30% by mass or less, the indicated value of the gas detection unit tends to increase as the Pt content increases. showed that. Further, in the carbonyl sulfide detector of Example 14, in the range where the Pt content is 0.30% by mass or more and 4.00% by mass or less, the indicated value of the gas detection unit tends to decrease as the Pt content increases. showed that. Further, in the carbonyl sulfide detector of Example 14, the gas detector reading value tended to be almost flat in the range of the Pt content of 4.00% by mass or more and 10.50% by mass or less. From this, it is considered that in the range of Pt content of 0.03% by mass or more and 0.30% by mass or less, the closer the Pt content is to 0.30% by mass, the more preferably it can be used as a catalyst. In the range where the Pt content is 0.03% by mass or more and 10.50% by mass or less, the indicated value of the gas detection unit changes over the entire range, and therefore, it is suitably used as a catalyst over the entire range. It is thought that it can be done.

(Example 15)
As shown in FIG. 16, in this confirmation experiment, the influence of the Pd content was investigated by a carbonyl sulfide detector (Example 15) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 15, the same device as the carbonyl sulfide detection device of Example 1 was used. However, as the catalyst 31b, the catalyst shown in Table 9 below was used.

In the carbonyl sulfide detector of Example 15, the gas to be detected G containing 10 ppm of carbonyl sulfide was flowed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side shown in FIG. 16 shows the time change of the indicated value of the gas detection unit in each catalyst. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time. Further, the graph on the right side shown in FIG. 16 shows the relationship between the indicated value in the graph on the left side at a predetermined time point and the Pd content rate. In this graph, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the Pd content rate.

As can be seen from the graph shown in FIG. 16, in the carbonyl sulfide detector of Example 15, the catalytic reaction of carbonyl sulfide can be carried out in the range of Pd content of 0.02% by mass or more and 9.84% by mass or less. It was. Further, in the carbonyl sulfide detector of Example 15, the indicated value of the gas detection unit tends to increase as the Pd content increases in the range of 0.02% by mass or more and 0.31% by mass or less of the Pd content. showed that. Further, in the carbonyl sulfide detector of Example 15, the gas detector reading value tended to be almost flat in the range of Pd content of 0.31% by mass or more and 9.84% by mass or less. From this, it is considered that in the range of Pd content of 0.02% by mass or more and 9.84% by mass or less, the larger the Pd content, the more preferably it can be used as a catalyst. Specifically, it is considered that the Pd content is preferably in the range of 0.31% by mass or more and 9.84% by mass or less.

(Examples 16 and 17)
As shown in FIGS. 17 and 18, in this confirmation experiment, the influence of miscellaneous gas (interference gas) was obtained by the carbonyl sulfide detector (Examples 16 and 17) using a catalyst containing an alkaline earth metal silicate containing Pt. I examined. As the carbonyl sulfide detection device of Examples 16 and 17, the same device as the carbonyl sulfide detection device of Example 1 was used. However, in the carbonyl sulfide detector of Example 16, 0.30% by mass of Pt _{, 76.77% by mass of SiO 2} , 19.94% by mass of CaO + MgO, and 2.99% by mass of the catalyst 31b were used. A catalyst containing other components was used. Further, in the carbonyl sulfide detector of Example 17, 10.50% by mass of Pt, 68.92% by mass of SiO ₂ , 17.90% by mass of CaO + MgO, and 2.68% by mass of the catalyst 31b were used. A catalyst containing other components was used.

As the miscellaneous gas, a detected gas G containing 109 ppm of acetone and a detected gas G containing 137 ppm of ethanol were used. As described above, alcohols (ethanol) and ketones (acetone) are components used as cleaning agents in the semiconductor manufacturing process. That is, in Examples 16 and 17, the influence of miscellaneous gas used in the semiconductor manufacturing process was investigated on the assumption that a carbonyl sulfide detecting device is used for detecting carbonyl sulfide in the atmosphere of the semiconductor manufacturing process.

In the carbonyl sulfide detectors of Examples 16 and 17, a detected gas G containing 5 ppm of carbonyl sulfide, a detected gas G containing 109 ppm of acetone, and a detected gas G containing 137 ppm of ethanol were flowed, and each gas was flown. The indicated value of the gas detection unit was obtained. The graphs shown in FIGS. 17 and 18 show the time change of the indicated value of the gas detection unit due to each gas. In these graphs, the vertical axis shows the indicated value of the gas detection unit, and the horizontal axis shows the time.

As can be seen from the graphs shown in FIGS. 17 and 18, in the carbonyl sulfide detectors of Examples 16 and 17, the indicated value of the detected gas G containing COS is about 5 ppm, whereas the detected value containing acetone is detected. The indicated value of the gas G was about 0.1 ppm, and the indicated value of the detected gas G containing ethanol was about 0.2 ppm. That is, both acetone and ethanol showed a value in which the indicated value of the gas detection unit was sufficiently smaller than that of COS. From this, it is considered that neither acetone nor ethanol interferes with the detection of COS when a catalyst containing an alkaline earth metal silicate containing Pt is used. That is, it is considered that a catalyst containing an alkaline earth metal silicate containing Pt can be suitably used for detecting carbonyl sulfide in the semiconductor manufacturing process.

[Modification example]
It should be noted that the embodiments and examples disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiments and examples, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the above embodiment, an example in which the carbonyl sulfide detector includes a flow rate control unit and a pump is shown, but the present invention is not limited to this. In the present invention, if the carbonyl sulfide decomposition unit and the gas detection unit are provided, the carbonyl sulfide detection device does not necessarily have to include the flow rate control unit and the pump.

Further, in the above embodiment, an example in which the catalyst is formed in a cotton-like shape is shown, but the present invention is not limited to this. In the present invention, the catalyst may be formed in, for example, granular, powdery, sheet-like, tablet-like, etc., as long as it can function as a catalyst.

Further, in the above embodiment, the gas detection unit includes an electrochemical gas detection unit, but the present invention is not limited to this. In the present invention, if the component generated by the hydrolysis of carbonyl sulfide can be detected, the gas detection unit may be, for example, an optical gas detection unit (sensor) or a semiconductor type gas detection unit (sensor). It may be included.

Further, in the above embodiment, an example is shown in which the catalyst portion of the present invention is a catalyst cylinder formed in a tubular shape, but the present invention is not limited to this. In the present invention, the shape of the catalyst portion is not particularly limited as long as the catalyst can be arranged, and the catalyst portion may have a shape other than the tubular shape.

30 Carbonyl sulfide decomposition part 31 Catalyst cylinder (catalyst part)
31b Catalyst 32 Heating mechanism 40 Gas detector 100 Carbonyl sulfide detector G Gas to be detected

Claims (10)

A catalyst part having a catalyst for catalytic reaction of carbonyl sulfide including at least hydrolysis, and
Equipped with a heating mechanism to trigger a catalytic reaction,
The catalyst is a carbonyl sulfide decomposition apparatus containing an alkaline earth metal silicate. The carbonyl sulfide decomposition apparatus according to claim 1, wherein the catalyst contains silica, magnesium, and calcium as the alkaline earth metal silicate. The carbonyl sulfide decomposition apparatus according to claim 2, wherein the catalyst further comprises at least one of platinum and palladium and alumina. The catalyst according to any one of claims 1 to 3, wherein the catalyst contains 50% by mass or more of silica and 10% by mass or more and 30% by mass or less of magnesia and calcia within a range in which the total does not exceed 100% by mass. The carbonyl sulfide decomposition apparatus according to the above. The sulfide according to claim 4, wherein the catalyst further contains 1% by mass or less of platinum, 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium in a range not exceeding 100% by mass in total. Carbonyl decomposition device. The carbonyl sulfide decomposition apparatus according to claim 4, wherein the catalyst further contains 30% by mass or less of alumina in a range not exceeding 100% by mass in total. The carbonyl sulfide decomposition apparatus according to any one of claims 1 to 6, wherein the heating mechanism is configured to heat the catalyst portion in a temperature range of 140 ° C. or higher and 500 ° C. or lower. The carbonyl sulfide decomposition apparatus according to claim 1 or 2, wherein the catalyst further contains 11% by mass or less of platinum or 10% by mass or less of palladium in a range not exceeding 100% by mass in total. A carbonyl sulfide decomposition unit for catalytic reaction of carbonyl sulfide including at least hydrolysis,
A gas detection unit for detecting a component in a gas to be detected generated by a catalytic reaction of the carbonyl sulfide by the carbonyl sulfide decomposition unit is provided.
The carbonyl sulfide decomposition part is
A catalyst part having a catalyst for catalytic reaction of the carbonyl sulfide including at least hydrolysis,
Including a heating mechanism for inducing a catalytic reaction,
The catalyst is a carbonyl sulfide detector containing an alkaline earth metal silicate. The carbonyl sulfide detection device according to claim 9, wherein the gas detection unit includes an electrochemical gas detection unit.

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