JP7419058B2 - Carbonyl sulfide decomposition equipment and carbonyl sulfide detection equipment - Google Patents

Description

The present invention relates to a carbonyl sulfide decomposition device and a carbonyl sulfide detection device, and more particularly to a sulfide carbonyl decomposition device and a carbonyl sulfide detection device in which carbonyl sulfide undergoes a catalytic reaction using a catalyst.

Carbonyl sulfide is attracting attention as a dry etching gas that is effective in suppressing shape abnormalities called bowing caused by passivation, which is the formation of a protective film on the sidewalls of pattern-etched structures during microfabrication of semiconductor devices. 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) has established a time-weighted average allowable concentration (TLV-TWA) of 5 ppm for carbonyl sulfide.

For this reason, it is necessary to appropriately detect leakage from the semiconductor device manufacturing process.

Conventionally, carbonyl sulfide detection devices that cause carbonyl sulfide to undergo a catalytic reaction using a catalyst are known (for example, see Patent Document 1).

The above Patent Document 1 discloses a carbonyl sulfide measuring device (carbonyl sulfide detection device) that measures 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 rather converts the concentration of hydrogen sulfide generated by catalytic reaction (hydrolysis) of carbonyl sulfide into the concentration of carbonyl sulfide. The device is configured to measure concentration indirectly.

JP 2017-3534 Publication

Although not specified in Patent Document 1, in semiconductor factories, volatile components such as Galden, Fluorinert, and Novec are often used as fluorinated refrigerants, and volatile components such as alcohols are often used as cleaning agents. Ingredients are well utilized. Therefore, when using the carbonyl sulfide measuring device as described in Patent Document 1 in a semiconductor factory, the catalytic reaction of carbonyl sulfide cannot be stably performed in an environment where volatile components such as fluorinated refrigerants and cleaning agents are present. The problem is that it needs to be done.

This invention was made in order to solve the above-mentioned problems, and one purpose of this invention is to solve the problems described above. Another object of the present invention is to provide a carbonyl sulfide decomposition device and a carbonyl sulfide detection device that can stably perform a catalytic reaction of carbonyl sulfide.

In order to achieve the above object, as a result of intensive studies, the inventor of the present application has discovered that a catalyst containing an alkaline earth metal silicate is resistant to poisoning by volatile components such as fluorinated refrigerants and cleaning agents commonly used in semiconductor factories. I gained new knowledge. That is, the carbonyl sulfide decomposition apparatus according to the first aspect of the present invention includes a catalyst section having a catalyst for catalytic reaction of carbonyl sulfide including at least hydrolysis, and a heating mechanism for causing the catalytic reaction. contains 50% by mass or more of silica and 10% by mass or more and 30% by mass of magnesia and calcia as alkaline earth metal silicate, within the range where the total mass% of the constituent components of the catalyst does not exceed 100% by mass. By containing, alkaline earth metal silicate is included as a main component.

In the carbonyl sulfide decomposition apparatus according to the first aspect of the invention, the catalyst is configured to contain an alkaline earth metal silicate, as described above. As a result, the catalyst containing alkaline earth metal silicate can be used even in environments where volatile components such as fluorinated refrigerants and cleaning agents commonly used in semiconductor factories are present. It can trigger the catalytic reaction of carbonyl sulfide while suppressing the poison. As a result, it is an object of the present invention to provide a carbonyl sulfide decomposition device that can stably perform a catalytic reaction of carbonyl sulfide even in an environment where volatile components such as fluorinated refrigerants and cleaning agents often used in semiconductor factories are present. I can do it.

In this case, preferably the catalyst further contains 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, so that the catalyst containing at least one of platinum and palladium and alumina can reduce carbonyl sulfide. The catalytic reaction effect can be suitably exhibited. Note that this point has been confirmed in experiments described below by the inventor of the present application.

In this case, the catalyst preferably contains not more than 1% by mass of platinum, not more than 2% by mass of palladium, or not more than 2% by mass of platinum and palladium, but the sum of the percentages by mass of the components of the catalyst exceeds 100% by mass. Including further to the extent not applicable. 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. A catalyst containing 2% by mass or less of palladium, or 2% by mass or less of platinum and palladium can suitably exhibit the effect of the catalytic reaction of carbonyl sulfide. Note that this point has been confirmed in experiments described below by the inventor of the present application.

In a structure in which the above-mentioned 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 alumina in a mass% of the constituent components of the catalyst. Further, the total amount does not exceed 100% by mass. With this configuration, the catalytic reaction can be promoted by the alumina of 30% by mass or less, so the effect of the catalytic reaction of carbonyl sulfide can be suitably exhibited by the catalyst containing the alumina of 30% by mass or less. . Note that this point has been confirmed in experiments described below 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 section in a temperature range of 140°C or more and 500°C or less. With this configuration, by setting the heating temperature of the heating mechanism to 140° C. or higher, the catalyst containing the alkaline earth metal silicate can suitably exhibit the effect of the catalytic reaction of carbonyl sulfide. Furthermore, 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 decreasing too much due to the influence of interfering gas. Note that this point has been confirmed in experiments described below by the inventor of the present application.

In the carbonyl sulfide decomposition apparatus according to the first aspect, preferably, the catalyst contains 11% by mass or less of platinum, or 10% by mass or less of palladium, and the total mass% of the components of the catalyst exceeds 100% by mass. Including further to the extent not applicable. 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. The catalyst included can suitably exhibit the catalytic reaction effect of carbonyl sulfide. Note that this point has been confirmed in experiments described below by the inventor of the present application.

The carbonyl sulfide detection device according to the second aspect of the present invention includes a carbonyl sulfide decomposition unit for causing a catalytic reaction of carbonyl sulfide including at least hydrolysis, and a carbonyl sulfide decomposition unit for detecting carbonyl sulfide generated by the catalytic reaction of the carbonyl sulfide decomposition unit. a gas detection unit that detects components in the gas; the carbonyl sulfide decomposition unit includes a catalyst unit that causes carbonyl sulfide to undergo a catalytic reaction including at least hydrolysis; and a heating mechanism for causing the catalytic reaction. , 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 as alkaline earth metal silicate, and the total mass% of the constituent components of the catalyst is 100% by mass. By containing the alkaline earth metal silicate in a range not exceeding , it contains an alkaline earth metal silicate as a main component.

In the carbonyl sulfide detection device according to the second aspect of the invention, the catalyst is configured to contain an alkaline earth metal silicate, as described above. As with the carbonyl sulfide decomposition apparatus according to the first aspect, this allows the catalytic reaction of carbonyl sulfide to be stabilized even in environments where volatile components such as fluorinated refrigerants and cleaning agents often used in semiconductor factories are present. It is possible to provide a carbonyl sulfide detection device that can perform the following steps.

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

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

FIG. 1 is a schematic diagram showing a carbonyl sulfide detection device according to one embodiment. 1 is a graph showing experimental results (relationship between COS adjusted concentration and indicated value) according to Example 1. 2 is a graph showing experimental results (relationship between Al ₂ O ₃ content and indicated value) according to Example 2. 3 is a graph showing experimental results (relationship between Pt/Al ₂ O ₃ content and indicated value) according to Example 3. It is a graph showing experimental results (relationship between Pd/Al ₂ O ₃ content and indicated value) according to Example 4. It is a graph showing experimental results (relationship between Pt:Pd (1:1)/Al ₂ O ₃ content and indicated value) according to Example 5. It is a graph showing experimental results (relationship between Pt:Pd (2:1)/Al ₂ O ₃ content and indicated value) according to Example 6. It is a graph showing experimental results (relationship between Pt:Pd (1:2)/Al ₂ O ₃ content and indicated value) according to Example 7. 7 is a graph showing experimental results (relationship between catalyst temperature and indicated value) according to Example 8. 7 is a graph showing experimental results (relationship between catalyst temperature and indicated value) according to Example 9. 12 is a graph showing experimental results (miscellaneous gas interference) according to Example 10. 12 is a graph showing experimental results (miscellaneous gas coexistence responsiveness) according to Example 11. 12 is a graph showing experimental results (exposure to miscellaneous gas saturated steam) according to Example 12. 7 is a graph showing experimental results (pressure loss versus catalyst bulk density) according to Example 13. 7 is a graph showing experimental results (relationship between Pt content and indicated value) according to Example 14. 7 is a graph showing experimental results (relationship between Pd content and indicated value) according to Example 15. 12 is a graph showing experimental results (miscellaneous gas interference) according to Example 16. 12 is a graph showing experimental results (miscellaneous gas interference) according to Example 17.

Embodiments of the present invention will be described below based on the drawings.

First, with reference to FIG. 1, the configuration of a carbonyl sulfide detection device 100 according to an embodiment will be described.

(Overall configuration of carbonyl sulfide detection device)
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 the detected gas generated by the catalytic reaction of carbonyl sulfide. be. The carbonyl sulfide detection device 100 can be used, for example, to detect carbonyl sulfide in an analysis sample, carbonyl sulfide in an atmosphere, and the like.

The carbonyl sulfide detection device 100 includes a flow rate control section 10, a pump 20, a carbonyl sulfide decomposition section 30, and a gas detection section 40. The flow rate control unit 10, the carbonyl sulfide decomposition unit 30, the gas detection unit 40, and the pump 20 are arranged from the upstream side to the downstream side in the flow direction of the detected gas G (gas of an analysis sample, gas in the atmosphere, etc.). They are fluidly connected in this order by a gas flow path 50. Note that the connection order of each component 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 section 30 is an example of a "carbonyl sulfide decomposition device" in 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 gas G to be detected. The carbonyl sulfide detection device 100 is configured so that the flow rate of the gas G to be detected is controlled by the flow rate control unit 10 so that a constant flow rate of the gas G to be detected flows. The flow rate of the gas to be detected G is not particularly limited, but may 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 passes through the gas flow path 50 and causes a pressure loss due to the carbonyl sulfide decomposition unit 30 .

The carbonyl sulfide decomposition unit 30 is configured to cause carbonyl sulfide in the detection gas G to undergo a catalytic reaction including at least hydrolysis. Specifically, the carbonyl sulfide decomposition section 30 includes a catalyst cylinder 31 and a heating mechanism 32. The catalyst cylinder 31 has a cylinder main 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 a catalyst 31b. The catalyst 31b is provided so that carbonyl sulfide in the detection gas G undergoes a catalytic reaction including at least hydrolysis. The catalytic reaction is, for example, the hydrolysis reaction of carbonyl sulfide shown in the following formula (1), or the hydrolysis reaction of hydrogen sulfide (chemical composition: H ₂ S) produced by the hydrolysis of carbonyl sulfide shown in the following formula (2). This may include oxidation reactions and the like. Note that the catalyst cylinder 31 is an example of a "catalyst section" in the claims.
COS+ _H2O → _H2S + _CO2 ...(1)
_H2S +3/ _2O2 → _SO2 + _H2O ...(2)

Here, in this embodiment, the catalyst 31b contains an alkaline earth metal silicate which is a basic catalyst. The catalyst 31b is preferably a basic material from the viewpoint of promoting the catalytic reaction of carbonyl sulfide. For example, the catalyst 31b includes alkaline earth metal oxides, alkali metal oxides, rare earth oxides, 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 ), etc. may be included. Further, iron oxide may be included as a material exhibiting amphoteric properties. 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 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 of magnesia (chemical composition: MgO) and calcia (chemical composition: CaO), the total of which exceeds 100% by mass. It is included to the extent that it is not. More preferably, the catalyst 31b contains 50% by mass or more of silica, and 10% by mass or more and 30% by mass of magnesia (chemical composition: MgO) and calcia (chemical composition: CaO), in a total of more than 100% by mass. It is included to the extent that it is not. 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, so long as the total does not exceed 100% by mass. More preferably, the catalyst 31b contains 30% by mass or less of alumina, with the total amount not exceeding 100% by mass. Preferably, the catalyst 31b does not contain alumina and contains 11% by mass or less of platinum, or 10% by mass or less of palladium, within a range in which the total does not exceed 100% by mass. Note that an experiment for decomposing carbonyl sulfide using the catalyst 31b containing an alkaline earth metal silicate will be described later.

Moreover, the catalyst 31b is formed into a cotton-like shape made of inorganic fiber. The catalyst 31b has an average fiber diameter of 2 μm or more and 4 μm or less. The cylinder body 31a of the catalyst cylinder 31 is filled with the cotton-like catalyst 31b. The bulk density of the packed catalyst 31b is not particularly limited, but from the viewpoint of reducing pressure loss, it can be, for example, 70 kg/m ³ or more and 250 kg/m ³ or less. The cotton-like catalyst 31b is provided to form a packed layer in the cylinder body 31a of the catalyst cylinder 31. The packed bed of the catalyst 31b is held inside the cylinder body 31a of the catalyst cylinder 31 by holding members 31c of the catalyst 31b arranged at both ends. The holding member 31c is, for example, quartz wool. Note that the holding member 31c is a member for holding the catalyst 31b, and is not limited to any material as long as it 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 section 32a and a heat insulating section 32b. The heating section 32a is configured to heat the catalyst 31b via the cylinder body 31a of the catalyst cylinder 31. The heating part 32a is, for example, a heating wire. The heating part 32a, which is a heating wire, is formed in a coil shape, for example, so as to surround the catalyst 31b with the cylinder main body 31a of the catalyst cylinder 31 interposed therebetween. Note that 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 section 32a is provided so as to face the packed bed of the catalyst 31b from one end to the other end of the packed bed of the catalyst 31b. That is, the heating section 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 part 32b is made of a heat insulating material and is provided so as to surround the heating part 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 with the heating portion 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 with the heating portion 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 with the heating portion 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 using the heating section 32a so as to maintain a substantially constant temperature. Heating that brings the catalyst cylinder 31 to a substantially constant temperature is not particularly limited; This can be done by controlling 32a.

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

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

In this embodiment, as described above, the catalyst 31b is configured to contain an alkaline earth metal silicate. As a result, the catalyst 31b containing alkaline earth metal silicate can prevent volatile components such as fluorinated refrigerants and cleaning agents, which are often used in semiconductor factories, even in environments where volatile components such as fluorinated refrigerants and cleaning agents are present. It is possible to cause a catalytic reaction of carbonyl sulfide while suppressing poisoning. As a result, the catalytic reaction of carbonyl sulfide can be carried out stably even in an environment where volatile components such as fluorinated refrigerants and cleaning agents often used in semiconductor factories are present.

Further, in this embodiment, as described above, the catalyst 31b contains silica, magnesium, and calcium as alkaline earth metal silicate. Thereby, the catalyst 31b containing silica, magnesium, and calcium can stably cause the catalytic reaction of carbonyl sulfide even in an environment where volatile components such as fluorine-based refrigerants and cleaning agents are present.

Further, in this embodiment, as described above, the catalyst 31b is configured to include 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, so the catalyst 31b containing at least one of platinum and palladium and alumina has an effect on the catalytic reaction of carbonyl sulfide. can be suitably demonstrated. Note that this point has been confirmed in experiments described below by the inventor of the present application.

Further, in this 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. Configure it 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 can be suitably used. can be demonstrated. Note that this point has been confirmed in experiments described below by the inventor of the present application.

Further, in this embodiment, as described above, the catalyst 31b contains platinum of 1% by mass or less, palladium of 2% by mass or less, or platinum and palladium of 2% by mass or less, and the total does not exceed 100% by mass. Configure to include in a 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. The catalyst 31b containing palladium or 2% by mass or less of platinum and palladium can suitably exhibit the effect of the catalytic reaction of carbonyl sulfide. Note that this point has been confirmed in experiments described below 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 within a range in which the total does not exceed 100% by mass. Thereby, the catalytic reaction can be promoted by the alumina in an amount of 30% by mass or less, so that the effect of the catalytic reaction of carbonyl sulfide can be suitably exhibited by the catalyst 31b containing the alumina in an amount of 30% by mass or less. Note that this point has been confirmed in experiments described below by the inventor of the present application.

Further, in this embodiment, as described above, the heating mechanism 32 is configured to heat the catalyst 31b portion in a temperature range of 140° C. or higher and 500° C. or lower. Thereby, by setting the heating temperature of the heating mechanism 32 to 140° C. or higher, the catalyst 31b containing the alkaline earth metal silicate can suitably exhibit the effect of the catalytic reaction of carbonyl sulfide. 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 decreasing too much due to the influence of interfering gas. Note that this point has been confirmed in experiments described below by the inventor of the present application.

Further, in this embodiment, as described above, the catalyst 31b is configured to contain platinum of 11% by mass or less or palladium of 10% by mass or less within a range in which the total does not exceed 100% by mass. As a result, the catalytic reaction can be promoted by platinum of 11% by mass or less or palladium of 10% by mass or less, so the catalyst 31b containing platinum of 11% by mass or less or palladium of 10% by mass or less , the catalytic reaction effect of carbonyl sulfide can be suitably exhibited. Note that this point has been confirmed in experiments described below by the inventor of the present application.

[Example]
Next, confirmation experiments (Examples 1 to 13) conducted to confirm the effects 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, a carbonyl sulfide detection device (Example 1) using a catalyst containing an alkaline earth metal silicate was used to detect gas G containing 5 ppm, 10 ppm, 15 ppm, and 20 ppm of carbonyl sulfide. 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, a 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 tube and an inner tube was used as the tube body 31a. As the outer tube, an alumina tube with an inner diameter of 12.9 mm was used, and as the inner tube, a quartz tube with 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), and 0.2% by mass of Pt (platinum); A catalyst containing 4% by mass of Al ₂ O ₃ and 2.9% by mass of other components was used.

Catalyst 31b was produced as follows. First, an alkaline earth metal silicate was prepared. As the alkaline earth metal silicate, "Isowool BSSR 1300 Bulk" manufactured by Isolite Kogyo Co., Ltd. was used. In this case, the prepared catalyst 31b may contain crystals of ulastonite, diopside, or enstatite, or may contain K ₂ O, Na ₂ O, Fe ₂ O ₃ , ZrO ₂ , P ₂ O ₄ , It may also 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 platinum-supported alumina was dispersed. Then, the alkaline earth metal silicate soaked in the viscous solvent was taken out from the viscous solvent and fired. As a result, a catalyst 31b containing SiO ₂ , MgO, CaO, Pt, Al ₂ O ₃ and other components at the above-described content was produced. Furthermore, as the gas detection unit 40, PS-7 (model number) manufactured by Shin Cosmos Electric Co., Ltd., which includes a constant potential electrolysis type gas detection unit, was used.

In the carbonyl sulfide detection device of Example 1, the gases G to be detected containing carbonyl sulfide of 5 ppm, 10 ppm, 15 ppm, and 20 ppm were flowed, and the indicated values of the gas detection unit were obtained. The graph on the left side of FIG. 2 shows the change over time in the indicated value of the gas detection unit for each detected gas G. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates 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 adjustment concentration. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates 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 no correlation between the adjusted COS concentration and the indicated value of the gas detection unit in the range of the adjusted COS concentration from 5 ppm to 20 ppm. It was seen. Specifically, in the carbonyl sulfide detection device of Example 1, the relationship between the adjusted COS concentration and the indicated value of the gas detection unit could be linearly approximated in the range of the adjusted COS concentration from 5 ppm to 20 ppm. . 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 using a carbonyl sulfide detection device (Example 2) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 2, a device similar to the carbonyl sulfide detection device of Example 1 was used. However, the catalyst shown in Table 1 below was used as the catalyst 31b.

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

As can be seen from the graph shown in FIG. 3, in the carbonyl sulfide detection device of Example 2, the catalytic reaction of carbonyl sulfide is carried out when the Al ₂ O ₃ content is in the range of 1.98% by mass to 21.44% by mass. I was able to do that. In addition, in the carbonyl sulfide detection device _of Example 2, as the Al ₂ O ₃ content increases in the range of 1.98 mass % to 13.67 mass %, _the gas detection part The indicated value showed a tendency to increase. In addition, in the carbonyl sulfide detection device of Example 2, the gas detection unit indication value tended to remain approximately flat in the range of Al ₂ O ₃ content from 13.67% by mass to 21.44% by mass. From this, it is considered that within the range of Al ₂ O ₃ content from 1.98% by mass to 21.44% by mass, the higher the Al ₂ O ₃ content, the more preferably it can be used as a catalyst. Specifically, it is considered preferable that the Al ₂ O ₃ content is 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 effects of Pt and Al ₂ O ₃ contents were investigated using a carbonyl sulfide detection device (Example 3) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 3, a device similar to the carbonyl sulfide detection device of Example 1 was used. However, the catalyst shown in Table 2 below was used as the catalyst 31b.

In the carbonyl sulfide detection device 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 of FIG. 4 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the graph on the right side shown in FIG. 4 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the Pt and Al ₂ O ₃ content rates. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pt and Al ₂ O ₃ content rates.

As can be seen from the graph shown in FIG. 4, in the carbonyl sulfide detection device 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 within the above range of 17.39% by mass or less. Further, in the carbonyl sulfide detection device of Example 3, the Pt content is 0.23 mass% or more and 0.92 mass% or less, and the Al ₂ O ₃ content is 4.43 mass% or more and 17.39 mass% or less. In the range, as the Pt content and Al ₂ O ₃ content decreased, the indicated value of the gas detection unit showed a tendency to increase. Further, in the carbonyl sulfide detection device of Example 3, the Pt content is 0.11 mass% or more and 0.23 mass% or less, and the Al ₂ O ₃ content is 2.03 mass% or more and 4.43 mass% or less. Within this range, the indicated values of the gas detection unit tended to remain roughly the same. From this, when 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 It is considered that the lower the ₂ O ₃ content, the more suitable it can be used as a catalyst. Specifically, it is preferable that the Pt content is in the range of 0.11% by mass or more and 0.23% by mass or less, and the Al ₂ O ₃ content is in the range of 2.03% by mass or more and 4.43% by mass or less. Conceivable.

Further, in the carbonyl sulfide detection device of Example 3, roughly speaking, the Pt content is 0.11% by mass or more and 0.57% by mass or less, and the Al ₂ O ₃ content is 2.03% by mass or more and 10% by mass. In the range of 88% by mass or less, the indicated value of the gas detection unit was larger than that of the carbonyl sulfide detection device of Example 2. This is considered to be because the oxidation reaction shown in the above formula (2) was promoted by Pt contained in the catalyst, which promoted the catalytic reaction of carbonyl sulfide.

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

In the carbonyl sulfide detection device of Example 4, the gas to be detected G containing 10 ppm of carbonyl sulfide was passed, and the indicated value of the gas detection unit by each catalyst was obtained. The graph on the left side of FIG. 5 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the graph on the right side shown in FIG. 5 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the Pd and Al ₂ O ₃ content rates. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pd and Al ₂ O ₃ content rates.

As can be seen from the graph shown in FIG. 5, in the carbonyl sulfide detection device 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 was able to be carried out within the above range of 15.67% by mass or less. Further, in the carbonyl sulfide detection device of Example 4, the Pd content is 0.11 mass% or more and 1.00 mass% or less, and the Al ₂ O ₃ content is 1.02 mass% or more and 9.03 mass% or less. In the range, as the Pd content and the Al ₂ O ₃ content increased, the indicated value of the gas detection unit showed a tendency to increase. Further, in the carbonyl sulfide detection device of Example 4, the Pd content is 1.00 mass% or more and 1.38 mass% or less, and the Al ₂ O ₃ content is 9.03 mass% or more and 15.67 mass% or less. In the range, as the Pd content and the Al ₂ O ₃ content increased, the indicated value of the gas detection unit showed a tendency to decrease. From this, if 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% by mass or less. It is considered that the closer the Al ₂ O ₃ content is to 9.03 mass % at .00 mass %, the more preferably it can be used as a catalyst. Specifically, it is preferable that the Pd content is in the range of 0.76% by mass or more and 1.38% by mass or less, and the Al ₂ O ₃ content is in the range of 6.87% by mass or more and 12.44% by mass or less. Conceivable.

Further, in the carbonyl sulfide detection device of Example 4, roughly speaking, the Pd content is 0.41% by mass or more and 1.74% by mass or less, and the Al ₂ O ₃ content is 3.71% by mass or more and 15% by mass. In the range of 67% by mass or less, the indicated value of the gas detection unit was larger than that of the carbonyl sulfide detection device of Example 2. This is considered to be because the oxidation reaction shown in formula (2) above was promoted by Pd contained in the catalyst, which promoted the catalytic reaction of carbonyl sulfide.

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

In the carbonyl sulfide detection device 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 of FIG. 6 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the graph on the right side shown in FIG. 6 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the content rates of Pt, Pd, and Al ₂ O ₃ . In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pt, Pd, and Al ₂ O ₃ content rates.

As can be seen from the graph shown in FIG. 6, in the carbonyl sulfide detection device 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 0.74% by mass or less. The catalytic reaction of carbonyl sulfide was able to be carried out when the Al ₂ O 3 content was 67% by mass or less and the Al 2 O ₃ content was in the range of 2.83% by mass or more and 20.09% by mass or less. Further, in the carbonyl sulfide detection device of Example 5, the Pt content is 0.11 mass% or more and 0.44 mass% or less, the Pd content is 0.09 mass% or more and 0.45 mass% or less, and Al ₂ In the range of O ₃ content from 2.83% by mass to 12.33% by mass, the indicated value of the gas detection unit tends to decrease as the Pt content, Pd content, and Al ₂ O ₃ content increase. showed that. Further, in the carbonyl sulfide detection device of Example 5, the Pt content is 0.44 mass% or more and 0.74 mass% or less, the Pd content is 0.45 mass% or more and 0.67 mass% or less, and Al ₂ In the range where the O ₃ content was 12.33% by mass or more and 20.09% by mass or less, the indicated value of the gas detection unit tended to remain flat. From this, the Pt content is 0.11 mass% or more and 0.74 mass% or less, the Pd content is 0.09 mass% or more and 0.67 mass% or less, and the Al ₂ O ₃ content is 2.83 mass%. In the range from % by mass to 20.09% by mass, it is considered that the smaller the Pt content, Pd content, and Al ₂ O ₃ content, the better 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 2.0% by mass or more. It is considered that the range of 83% by mass or more and 8.08% by mass or less is preferable.

Further, in the carbonyl sulfide detection device of Example 5, the Pt content is generally 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 of Al ₂ O ₃ content of 2.83 mass % or more and 12.33 mass % or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. This is considered to be because the oxidation reaction shown in the above formula (2) was promoted by Pt and Pd contained in the catalyst, which promoted the catalytic reaction of carbonyl sulfide.

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

In the carbonyl sulfide detection device of Example 7, a 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 of FIG. 7 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the graph on the right side shown in FIG. 7 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the content rates of Pt, Pd, and Al ₂ O ₃ . In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pt, Pd, and Al ₂ O ₃ content rates.

As can be seen from the graph shown in FIG. 7, in the carbonyl sulfide detection device 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 0.69% by mass or less. The catalytic reaction of carbonyl sulfide was able to be carried out when the Al ₂ O 3 content was 37% by mass or less and the Al 2 O ₃ content was in the range of 2.35% by mass or more and 16.50% by mass or less. Further, in the carbonyl sulfide detection device 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 of O ₃ content from 2.35% by mass to 11.14% by mass, the indicated value of the gas detection unit tends to decrease as the Pt content, Pd content, and Al ₂ O ₃ content increase. showed that. In addition, in the carbonyl sulfide detection device of Example 6, the Pt content is 0.47 mass% or more and 0.69 mass% or less, the Pd content is 0.25 mass% or more and 0.37 mass% or less, and Al ₂ In the range where the O ₃ content was 11.14% by mass or more and 16.50% by mass or less, the indicated value of the gas detection unit tended to remain flat. From this, it can be seen that 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% by mass or less. It is considered that in the range from 16.50% by mass to 16.50% by mass, the smaller the Pt content, Pd content, and Al ₂ O ₃ content, the better 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 2.0% by mass or more. It is considered that the range of 35% by mass or more and 6.63% by mass or less is preferable.

Further, in the carbonyl sulfide detection device of Example 6, the Pt content is generally 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 of Al ₂ O ₃ content of 2.35 mass % or more and 8.92 mass % or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. This is considered to be because the oxidation reaction shown in the above formula (2) was promoted by Pt and Pd contained in the catalyst, which promoted the catalytic reaction of carbonyl sulfide.

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

In the carbonyl sulfide detection device of Example 7, a 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 of FIG. 8 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the right graph shown in FIG. 8 shows the relationship between the indicated value at a predetermined time point of the left graph and the Pt, Pd, and Al ₂ O ₃ content rates. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pt, Pd, and Al ₂ O ₃ content rates.

As can be seen from the graph shown in FIG. 8, in the carbonyl sulfide detection device of Example 7, the Pt content was 0.05 mass% or more and 0.46 mass% or less, and the Pd content was 0.13 mass% or more and 0.46 mass% or less. The catalytic reaction of carbonyl sulfide was able to be carried out when the Al ₂ O 3 content was 85% by mass or less and the Al 2 O ₃ content was in the range of 2.04% by mass or more and 16.36% by mass or less. Further, in the carbonyl sulfide detection device 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 the Al ₂ In a 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 detection unit tends to decrease as the Pt content, Pd content, and Al ₂ O ₃ content increase. showed that. From this, it can be seen that 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% by mass or less. It is considered that in the range from 16.36% by mass to 16.36% by mass, the smaller the Pt content, Pd content, and Al ₂ O ₃ content, the better 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 2.0% by mass or more. It is thought that a preferable range is 0.04% by mass or more and 7.20% by mass or less.

Further, in the carbonyl sulfide detection device of Example 7, the Pt content is generally 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 of Al ₂ O ₃ content of 2.04 mass % or more and 7.20 mass % or less, the indicated value of the gas detection unit became larger than that of the carbonyl sulfide detection device of Example 2. This is considered to be because the oxidation reaction shown in the above formula (2) was promoted by Pt and Pd contained in the catalyst, which promoted the catalytic reaction of carbonyl sulfide.

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 catalyst temperature (heating temperature) was investigated using a carbonyl sulfide detection device (Example 8) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device in Example 8, a device similar to the carbonyl sulfide detection device in Example 1 was used. However, the catalyst shown in Table 7 below was used as the catalyst 31b.

In the carbonyl sulfide detection device of Example 8, the gas to be detected G containing 20 ppm of carbonyl sulfide was flowed, 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 indicates the indicated value (normalized value) of the gas detection unit, and the horizontal axis indicates the catalyst temperature (heating temperature).

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

If the catalyst temperature is higher than 500°C, the influence of interfering gas, which will be described later, becomes too large, so it is considered that the catalyst temperature is preferably 500°C or lower. Further, if the catalyst temperature is lower than 200°C, the indicated value of the gas detection unit becomes too small, so it is considered that the catalyst temperature is preferably 200°C or higher. Further, since the value is about twice or more than the value indicated by 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 more and 500°C or less. Further, since the value is about three times or more than the value indicated by 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 more and 400°C or less.

(Example 9)
As shown in FIG. 10, in this confirmation experiment, the influence of catalyst temperature (heating temperature) was investigated using a carbonyl sulfide detection device (Example 9) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 9, a device similar to 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 the catalyst 31b, 55.1% by mass of SiO ₂ , 22.63% by mass of MgO, 3.94% by mass of CaO, 2.95% by mass of Fe ₂ O ₃ , 2 .51% by weight _Al2O3 , 0.08% _by weight Pt, and 12.79% by weight Ig. A catalyst containing Loss (loss on ignition) was used.

In the carbonyl sulfide detection device of Example 9, the gas to be detected G containing 10 ppm of carbonyl sulfide was passed through, 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 in the indicated value of the gas detection section. In this graph, the vertical axis indicates the indicated value (normalized value) of the gas detection unit, and the horizontal axis indicates the catalyst temperature (heating temperature).

As can be seen from the graph shown in FIG. 10, the carbonyl sulfide detection device of Example 9 was able to carry out the catalytic reaction of carbonyl sulfide in the temperature range of 140°C to 400°C. Furthermore, in the carbonyl sulfide detection device of Example 9, the indicated value of the gas detection unit showed a tendency to increase as the catalyst temperature increased up to 260°C. Moreover, after 260° C., the indicated value of the gas detection unit showed a tendency 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 preferably it can be used as a catalyst.

In the carbonyl sulfide detection device of Example 9, if the catalyst temperature is lower than 140°C, the indicated value of the gas detection section becomes too small, so it is considered that the catalyst temperature is preferably 140°C or higher. Further, it is considered that it is more preferable that the catalyst temperature is in the range of 160°C or more and 400°C or less, as the catalyst temperature is about twice or more of the value indicated by 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 using a carbonyl sulfide detection device (Example 10) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device in Example 10, a device similar to the carbonyl sulfide detection device in Example 1 was used. The miscellaneous gases include a detected gas G containing 329 ppm HT-70, a detected gas G containing 223 ppm FC-43, a detected gas G containing 245 ppm HFE-7100, and a detected gas G containing 109 ppm 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 (Galden) and FC-43 (Florinat). and HFE-7100 (Novec) are components used as fluorine-based inert refrigerants in chillers in semiconductor manufacturing processes. That is, in Example 10, the influence of miscellaneous gases used in the semiconductor manufacturing process was investigated assuming that a carbonyl sulfide detection device was used to detect carbonyl sulfide in the atmosphere of the semiconductor manufacturing process.

In the carbonyl sulfide detection device of Example 10, a detected gas G containing 5 ppm carbonyl sulfide, a detected gas G containing 329 ppm HT-70, a detected gas G containing 223 ppm FC-43, and 245 ppm HFE-7100. , a gas to be detected G containing 109 ppm of acetone, and a gas to be detected G containing 141 ppm of ethanol were flowed, and the indicated values of the gas detection unit for each gas were obtained. The graph shown in FIG. 11 shows changes over time in the indicated value of the gas detection unit due to each gas. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time.

As can be seen from the graph shown in FIG. 11, in the carbonyl sulfide detection device of Example 10, the indicated value of the detected gas G containing COS was approximately 5 ppm, whereas the indicated value of the detected gas G containing HT-70 was approximately 5 ppm. The indicated value is approximately 0.1 ppm, the indicated value of the detected gas G containing FC-43 is approximately 0.1 ppm, the indicated value of the detected gas G containing HFE-7100 is approximately 0.2 ppm, the detected gas containing acetone The indicated value of G was approximately 0.5 ppm, and the indicated value of the detected gas G containing ethanol was approximately 0.6 ppm. That is, HT-70, FC-43, HFE-7100, acetone, and ethanol all showed sufficiently smaller values indicated by the gas detection unit than 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 will substantially interfere with COS detection. That is, it is considered that a catalyst containing an alkaline earth metal silicate can be suitably used for detecting carbonyl sulfide in a semiconductor manufacturing process.

(Example 11)
As shown in Figure 12, in this confirmation experiment, a carbonyl sulfide detection device (Example 11) using a catalyst containing an alkaline earth metal silicate was used to detect the response in an environment where COS and miscellaneous gases (interference gases) coexist. I looked into gender. As the carbonyl sulfide detection device of Example 11, a device similar to 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, and a detected gas G containing 245 ppm of HFE-7100 were used.

In the carbonyl sulfide detection device of Example 11, the detected gas G contains 5 ppm of carbonyl sulfide, the detected gas G contains 5 ppm of carbonyl sulfide, 329 ppm of HT-70, 223 ppm of FC-43, and 245 ppm of HFE-7100. Gas G (four gas coexistence gas) was passed through each gas, and the indicated value of the gas detection unit for each gas was obtained. The graph shown in FIG. 12 shows changes over time in the indicated value of the gas detection unit due to each gas. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time.

As can be seen from the graph shown in FIG. 12, in the carbonyl sulfide detection device of Example 11, the indicated value of the detected gas G containing 5 ppm of COS was approximately 5.4 ppm, whereas the indicated value of the gas coexisting with 4 gases was approximately 5.4 ppm. The value was approximately 5.7 ppm. That is, both the gas to be detected G containing 5 ppm of COS and the gas coexisting with four gases showed similar values in the indicated values of the gas detection unit. 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 a semiconductor manufacturing process.

(Example 12)
As shown in Figure 13, in this confirmation experiment, the deterioration of the catalyst due to saturated vapor of miscellaneous gas (interference gas) was investigated using a carbonyl sulfide detection device (Example 12) using a catalyst containing an alkaline earth metal silicate. . As the carbonyl sulfide detection device in Example 12, a device similar to the carbonyl sulfide detection device in Example 1 was used. As miscellaneous gases, 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 detection gas G containing 5.8 vol% ethanol and a detection gas G 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. This is a highly concentrated gas that is unimaginable in semiconductor manufacturing processes. That is, in Example 12, an accelerated test was conducted using a highly concentrated gas.

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

As can be seen from the graph shown in FIG. 13, even after 30 minutes of exposure to each saturated vapor gas, an indication value of about 5 ppm from the gas detection unit was obtained for 5 ppm COS. This is because the catalyst containing 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, catalysts containing alkaline earth metal silicates are highly resistant to poisoning by the fluorine components HT-70, FC-43, and HFE-7100, and are resistant to poisoning 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, pressure loss with respect to catalyst bulk density was investigated using a carbonyl sulfide detection device (Example 13) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 13, a device similar to the carbonyl sulfide detection device of Example 1 was used.

In the carbonyl sulfide detection device of Example 13, the gas to be detected G was passed, and the pressure loss with respect to the bulk density of the catalyst at each temperature was obtained. The graph shown in FIG. 14 shows changes in pressure loss with respect to bulk density at each temperature. In this graph, the vertical axis shows pressure loss, and the horizontal axis shows catalyst bulk density.

As can be seen from the graph shown in FIG. 14, in the carbonyl sulfide detection device of Example 13, the pressure loss tended to increase as the catalyst bulk density increased in the temperature range of 200° C. or higher and 450° C. or lower. Furthermore, in the carbonyl sulfide detection device 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 detection device 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. It is considered preferable that Further, considering the margin from a practical standpoint, it is considered that the catalyst bulk density is more preferably 200 kg/m ³ or less. Further, from the viewpoint of ensuring the amount of catalyst packed, it is considered preferable that the bulk density of the catalyst is 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 using a carbonyl sulfide detection device (Example 14) using a catalyst containing an alkaline earth metal silicate. As the carbonyl sulfide detection device of Example 14, a device similar to the carbonyl sulfide detection device of Example 1 was used. However, the catalyst shown in Table 8 below was used as the catalyst 31b.

In the carbonyl sulfide detection device 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 of FIG. 15 shows the change over time in the indicated value of the gas detection unit for each catalyst. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time. Moreover, the graph on the right side shown in FIG. 15 shows the relationship between the indicated value at a predetermined time point in the graph on the left side and the Pt content rate. In this graph, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates the Pt content rate.

As can be seen from the graph shown in FIG. 15, the carbonyl sulfide detection device of Example 14 was able to carry out the catalytic reaction of carbonyl sulfide when the Pt content was in the range of 0.03% by mass to 10.50% by mass. Ta. In addition, in the carbonyl sulfide detection device of Example 14, the indicated value of the gas detection unit tends to increase as the Pt content increases in the range of 0.03 mass% to 0.30 mass% Pt content. showed that. In addition, in the carbonyl sulfide detection device of Example 14, the indicated value of the gas detection unit tends to decrease as the Pt content increases in the range of 0.30 mass% to 4.00 mass%. showed that. In addition, in the carbonyl sulfide detection device of Example 14, the gas detection unit indication value tended to remain approximately the same in the range of Pt content of 4.00% by mass to 10.50% by mass. From this, it is considered that in a range where the Pt content is 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 addition, 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 remains high over the entire range, so it is suitable for use as a catalyst over the entire range. It is thought that it is possible to do so.

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

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

As can be seen from the graph shown in FIG. 16, the carbonyl sulfide detection device of Example 15 is capable of carrying out the catalytic reaction of carbonyl sulfide when the Pd content is in the range from 0.02% by mass to 9.84% by mass. Ta. In addition, in the carbonyl sulfide detection device 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 mass% or more and 0.31 mass% or less. showed that. In addition, in the carbonyl sulfide detection device of Example 15, the gas detection unit indication value tended to remain approximately flat in the range of Pd content of 0.31% by mass to 9.84% by mass. From this, it is considered that in a range where the Pd content is 0.02% by mass or more and 9.84% by mass or less, the higher the Pd content, the more preferably it can be used as a catalyst. Specifically, it is considered preferable that the Pd content is in a range of 0.31% by mass or more and 9.84% by mass or less.

(Examples 16 and 17)
As shown in Figures 17 and 18, in this confirmation experiment, the effects of miscellaneous gases (interference gases) were measured using a carbonyl sulfide detection device (Examples 16 and 17) using a catalyst containing an alkaline earth metal silicate containing Pt. I looked into it. As the carbonyl sulfide detection device in Examples 16 and 17, a device similar to the carbonyl sulfide detection device in Example 1 was used. However, in the carbonyl sulfide detection device of Example 16, the catalyst 31b contained 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 A catalyst containing other components was used. In addition, in the carbonyl sulfide detection device of Example 17, as the catalyst 31b, 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 A catalyst containing other components was used.

Further, as miscellaneous gases, a gas to be detected G containing 109 ppm of acetone and a gas to be detected G containing 137 ppm of ethanol were used. As mentioned above, alcohols (ethanol) and ketones (acetone) are components used as cleaning agents in semiconductor manufacturing processes. That is, in Examples 16 and 17, the influence of miscellaneous gases used in the semiconductor manufacturing process was investigated assuming that a carbonyl sulfide detection device was used to detect carbonyl sulfide in the atmosphere of the semiconductor manufacturing process.

In the carbonyl sulfide detection devices of Examples 16 and 17, a detection gas G containing 5 ppm of carbonyl sulfide, a detection gas G containing 109 ppm of acetone, and a detection gas G containing 137 ppm of ethanol were passed through each gas. The indicated value of the gas detection unit was obtained. The graphs shown in FIGS. 17 and 18 show changes over time in the indicated value of the gas detection unit due to each gas. In these graphs, the vertical axis indicates the indicated value of the gas detection unit, and the horizontal axis indicates time.

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

[Modified example]
Note that the embodiments and examples disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments and examples described above, and further includes all changes (modifications) within the meaning and range equivalent to the claims.

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

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

Further, in the above embodiment, an example was shown in which the gas detection section includes an electrochemical gas detection section, but the present invention is not limited to this. In the present invention, the gas detection unit may be an optical gas detection unit (sensor) or a semiconductor gas detection unit (sensor) as long as it is possible to detect components generated by hydrolysis of carbonyl sulfide. May contain.

Further, in the above embodiment, an example was shown in which the catalyst section of the present invention is a cylindrical catalyst tube, 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 a cylindrical shape.

30 Carbonyl sulfide decomposition section 31 Catalyst tube (catalyst section)
31b catalyst 32 heating mechanism 40 gas detection section 100 carbonyl sulfide detection device G gas to be detected

Claims (8)

a catalyst part having a catalyst for catalytic reaction of carbonyl sulfide including at least hydrolysis;
a heating mechanism for causing a catalytic reaction;
The catalyst contains, as an alkaline earth metal silicate, 50% by mass or more of silica, 10% by mass or more and 30% by mass or less of magnesia and calcia, and the total mass% of the constituent components of the catalyst exceeds 100% by mass. A carbonyl sulfide decomposition device containing the alkaline earth metal silicate as a main component by including the alkaline earth metal silicate within a range not limited to the above . The carbonyl sulfide decomposition apparatus according to claim 1 , wherein the catalyst further includes at least one of platinum and palladium, and alumina. 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 mass% of the constituent components of the catalyst does not exceed 100% by mass. The carbonyl sulfide decomposition apparatus according to claim 1 , comprising: The carbonyl sulfide decomposition apparatus according to claim 1 , wherein the catalyst further contains 30% by mass or less of alumina, to the extent that the total mass% of the constituent components of the catalyst does not exceed 100% by mass. The carbonyl sulfide decomposition apparatus according to any one of claims 1 to 4 , wherein the heating mechanism is configured to heat the catalyst section in a temperature range of 140°C or more and 500°C or less. The sulfurized catalyst according to claim 1 , wherein the catalyst further contains 11% by mass or less of platinum or 10% by mass or less of palladium, as long as the sum of the mass% of the constituent components of the catalyst does not exceed 100% by mass. Carbonyl decomposition equipment. a carbonyl sulfide decomposition unit for catalytic reaction of carbonyl sulfide including at least hydrolysis;
a gas detection unit that detects a component in a detected gas generated by a catalytic reaction of the carbonyl sulfide by the carbonyl sulfide decomposition unit;
The carbonyl sulfide decomposition part is
a catalyst part having a catalyst for the carbonyl sulfide to undergo a catalytic reaction including at least hydrolysis;
a heating mechanism for causing a catalytic reaction;
The catalyst contains, as an alkaline earth metal silicate, 50% by mass or more of silica, 10% by mass or more and 30% by mass or less of magnesia and calcia, and the total mass% of the constituent components of the catalyst exceeds 100% by mass. A carbonyl sulfide detection device comprising the alkaline earth metal silicate as a main component by including the above alkaline earth metal silicate within a range where the alkaline earth metal silicate is not included . The carbonyl sulfide detection device according to claim 7 , wherein the gas detection section includes an electrochemical gas detection section.

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