JP7437242B2 - Manganese-added barium zirconate particles and organic matter decomposition catalyst containing them - Google Patents

Description

The present invention relates to manganese-doped barium zirconate particles, and more specifically, the substitution rate of zirconium by manganese is 8 mol % or more, the particles are fine and highly crystalline, and can be suitably used as an organic substance decomposition catalyst. The present invention relates to manganese-doped barium zirconate particles.

Manganese-doped barium zirconate particles are already known as an organic substance decomposition catalyst for thermally decomposing organic substances (see Patent Document 1). The above manganese-doped barium zirconate particles are manufactured by a solid phase method. That is, for example, barium carbonate, zirconium oxide, and trimanganese tetroxide (Mn ₃ O ₄ ) are heat-treated at 1100° C. at a Ba:Zr:Mn molar ratio of 1:0.9:0.1, and the resulting powder is After shaping, it is fired at 1100°C and pulverized to obtain manganese-doped barium zirconate particles in which 10 mol% of zirconium is replaced with manganese.

Manganese-added barium zirconate particles are preferably fine particles with a high specific surface area in order to be used as an organic substance decomposition catalyst, but as is well known, manganese-added barium zirconate particles are generally It is difficult to obtain perovskite-type composite oxides as fine particles, including barium zirconate particles.

On the other hand, in manganese-added barium zirconate particles, by increasing the substitution rate of zirconium with manganese, which is a combustion active component, the catalytic activity as an organic matter decomposition catalyst is improved. The crystallinity of the added barium zirconate particles decreases. Furthermore, part of the manganese does not dissolve in the barium zirconate and tends to generate by-products, and as a result, the obtained manganese-added barium zirconate particles form a mixed phase with the above-mentioned by-products. Manganese-added barium zirconate having such low crystallinity or mixed phase has low activity as an organic matter decomposition catalyst.

Japanese Patent Application Publication No. 2015-229137

In particular, the present invention was made to solve the above-mentioned problems in manganese-doped barium zirconate particles used as an organic substance decomposition catalyst, and the substitution rate of zirconium by manganese is 8 mol% or more, and the specific surface area is The object of the present invention is to provide manganese-added barium zirconate particles that are fine and have a high crystallite diameter/specific surface area particle diameter in the range of 0.3 to 1.1, and have high crystallinity. .

Particularly, in the present invention, preferably, the substitution rate of zirconium by manganese is substantially 10 mol % or more, the specific surface area is high and fine, and the crystallite diameter/specific surface area equivalent particle diameter is 0.4 to 1. It is an object of the present invention to provide manganese-doped barium zirconate particles that have a particle diameter of 0.1, have high crystallinity, and can be suitably used as an organic substance decomposition catalyst.

According to the invention, compositional formula (I)
BaZr _1-x Mn _x O _3-δ
(In the formula, x is a number satisfying 0.08≦x≦0.25, and δ indicates the amount of oxygen vacancies.)
Manganese-doped barium zirconate particles are provided, which are represented by the following formula, have a crystallite diameter/specific surface area equivalent particle diameter in the range of 0.455 to 1.090 , and have a specific surface area of 8.2 m ² /g or more .

According to the invention, the manganese-doped barium zirconate particles preferably have a specific surface area of 8 m ² /g or more.

Further, according to the present invention, there is provided an organic matter decomposition catalyst containing the manganese-doped barium zirconate particles.

The manganese-added barium zirconate particles according to the present invention have a substitution rate of zirconium by manganese of 8 mol % or more, a high specific surface area, are fine, and have a crystallite diameter/specific surface area equivalent particle diameter of 0.3 to 1. 1, indicating high crystallinity.

Such manganese-added barium zirconate particles can be suitably used as an organic substance decomposition catalyst having high combustion catalytic activity.

3 shows powder X-ray diffraction patterns of manganese-doped barium zirconate particles according to Example 4 of the present invention and Comparative Example 2.

The manganese-doped barium zirconate particles according to the present invention have the composition formula (I)
BaZr _1-x Mn _x O _3-δ
(In the formula, x is a number satisfying 0.08≦x≦0.25, and δ indicates the amount of oxygen vacancies.)
The crystallite diameter/specific surface area equivalent particle diameter is in the range of 0.3 to 1.1.

In the present invention, in the composition formula (I), the Mn/(Zr+Mn) molar ratio, that is, the value of x, is referred to as the substitution ratio of zirconium by manganese, and Mn/(Zr+Mn)×100 is the substitution ratio of zirconium by manganese ( (mol%).

When the substitution ratio x of zirconium by manganese is smaller than 0.08, such manganese-doped barium zirconate particles do not have high catalytic activity as an organic matter decomposition catalyst, while when x is larger than 0.25. However, such manganese-added barium zirconate particles contain foreign substances or foreign substances derived from by-products containing manganese, and similarly do not have high catalytic activity as an organic matter decomposition catalyst.

The crystallite diameter/specific surface area equivalent particle diameter is a measure of the crystallinity of the manganese-doped barium zirconate particles, and the manganese-doped barium zirconate particles according to the present invention have a crystallite diameter/specific surface area equivalent particle diameter of 0.3. -1.1 and has high crystallinity.

Generally, the closer the crystallite diameter/specific surface area equivalent particle diameter is to 1, the closer the geometric particle diameter and single crystal size are, and therefore the higher the crystallinity of the particles.

Usually, the specific surface area equivalent diameter of particles is larger than the crystallite diameter. In other words, the value of crystallite diameter/specific surface area equivalent particle diameter is often smaller than 1, but the specific surface area equivalent diameter is calculated assuming that each particle is perfectly spherical, so the particle shape is not perfectly spherical. In this case, the value of crystallite diameter/specific surface area converted particle diameter may be larger than 1 due to the difference from the actual particle shape.

The manganese-doped barium zirconate particles according to the present invention preferably have a specific surface area of 8 m ² /g or more, are fine, and can be suitably used as an organic matter decomposition catalyst.

For example, when carbon black is thermally decomposed (combusted), manganese-doped barium zirconate particles according to the present invention are mixed with carbon black as a thermal decomposition catalyst, and thermogravimetric analysis is performed to determine the thermal decomposition behavior of carbon black. If the peak top temperature according to the differential curve of weight change is used as an indicator of activity, as will be described later, the peak top temperature is significantly higher than when manganese-added barium zirconate particles according to a comparative example are used as a thermal decomposition catalyst. Therefore, by using the manganese-doped barium zirconate particles according to the invention as a pyrolysis catalyst, carbon black can be combusted with less energy.

The manganese-doped barium zirconate particles represented by the composition formula (I) according to the present invention can preferably be obtained by the method described below.

That is,
(a) A step of mixing barium hydroxide, zirconium hydroxide, manganese hydroxide, and manganese-added barium zirconate seed crystals having an average particle size of 2.0 μm or less with water to obtain a first slurry. ,
(b) a step of subjecting the first slurry to a hydrothermal reaction to obtain a second slurry as a reaction mixture, and (c) a step of treating the second slurry with an acid and then washing with water,
In the above step (a), the Mn/(Zr+Mn) molar ratio of the first slurry is in the range of 0.08 to 0.25, and the Ba/(Zr+Mn) molar ratio is in the range of 1.0 to 2.0. It is something to do.

In the step (a), when zirconium hydroxide and manganese hydroxide are used at a Mn/(Zr+Mn) molar ratio of less than 0.08 in the first slurry, high catalytic activity is obtained. It is not possible to obtain manganese-doped barium zirconate particles as an organic matter decomposition catalyst. On the other hand, in the above step (a), when zirconium hydroxide and manganese hydroxide are used at a Mn/(Zr+Mn) molar ratio greater than 0.25, the resulting manganese-doped barium zirconate particles may contain foreign substances. This is not preferable because it contains foreign phases.

Further, in the step (a), when barium hydroxide, zirconium hydroxide, and manganese hydroxide are used with the Ba/(Zr+Mn) molar ratio of the first slurry being smaller than 1.0, , it is difficult to obtain manganese-doped barium zirconate particles with a large specific surface area. However, when barium hydroxide, zirconium hydroxide, and manganese hydroxide are used with the Ba/(Zr+Mn) molar ratio above 2.0, the final resultant manganese-doped barium zirconate particles contains a foreign phase, which is not desirable.

In the production of manganese-doped barium zirconate particles according to the present invention described above, the Mn/(Zr+Mn) molar ratio and Ba/(Zr+Mn) molar ratio in the above step (a) are the same as the barium hydroxide used in the step (a). Based on the amount of zirconium hydroxide and manganese hydroxide, that is, the amount charged. On the other hand, the Mn/(Zr+Mn) molar ratio in the manganese-doped barium zirconate particles finally obtained by the method described above is based on the analysis method described below.

In the present invention, in the composition formula (I), the Mn/(Zr+Mn) molar ratio, that is, the value of x, is referred to as the substitution ratio of zirconium by manganese, and Mn/(Zr+Mn)×100 is the substitution ratio of zirconium by manganese ( (mol%).

According to the above manufacturing method, in step (a), the first slurry has a Mn/(Zr+Mn) molar ratio in the range of 0.8 to 0.25, and a Ba/(Zr+Mn) molar ratio of 1. .0 to 2.0, and in step (b), the first slurry is subjected to a hydrothermal reaction to obtain a second slurry, and the second slurry thus obtained is treated with an acid, By washing with water to remove excess barium hydroxide, the zirconium substitution rate with manganese is 8 mol% or more, the specific surface area is high, the particles are fine, and the crystallite size/specific surface area equivalent particle size is It is possible to obtain manganese-doped barium zirconate particles represented by the above compositional formula (I) in the range of 0.3 to 1.1.

Particularly, in the step (a), the Mn/(Zr+Mn) molar ratio of the first slurry is in the range of 0.095 to 0.22, and the Ba/(Zr+Mn) molar ratio is in the range of 1.0 to 2.0. 0 range, then similarly, in step (b), the first slurry is subjected to a hydrothermal reaction to obtain a second slurry, and the second slurry thus obtained is treated with an acid, By washing with water to remove excess barium hydroxide, the manganese-doped barium zirconate particles according to a preferred embodiment of the present invention, that is, the crystallite diameter/specific surface area equivalent particle diameter is 0.4 to 1.1. Compositional formula (Ia) in the range of
BaZr _1-x Mn _x O _3-δ
(In the formula, x is a number satisfying 0.095≦x≦0.22, and δ indicates the amount of oxygen vacancies.)
It is possible to obtain manganese-doped barium zirconate particles represented by:

Also in the manganese-doped barium zirconate particles represented by the above compositional formula (Ia), the definitions regarding the substitution ratio and substitution rate are the same as described above.

Thus, according to a preferred embodiment of the present invention, the substitution rate of zirconium by manganese is substantially 10 mol% or more, the specific surface area is high and fine, and the crystallite diameter/specific surface area equivalent particle diameter is 0.4. According to a particularly preferred embodiment, the value is close to 1, it is possible to obtain manganese-doped barium zirconate particles that are highly crystalline and can be suitably used as an organic substance decomposition catalyst.

In particular, according to a preferred embodiment of the present invention, the manganese-doped barium zirconate particles have a specific surface area of 8 m ² /g or more.

In the production of the manganese-doped barium zirconate particles according to the present invention described above, as the barium hydroxide, barium hydroxide anhydrate, monohydrate, octahydrate, etc. can be used.

As the zirconium hydroxide, commercially available anhydrates and various hydrates of zirconium hydroxide can be used. However, the above commercial products easily absorb water and are unstable. Therefore, as the above-mentioned zirconium hydroxide, preferably, a water-soluble zirconium compound such as zirconium oxychloride or zirconium acetate is reacted with an excess amount of an alkaline compound such as sodium hydroxide, potassium hydroxide, or aqueous ammonia in water. Preference is given to producing zirconium hydroxide quantitatively and using the zirconium hydroxide as a wet cake obtained in this way.

Commercially available manganese hydroxides can be used as the manganese hydroxide, but commercially available manganese hydroxides also tend to absorb water and are unstable. Therefore, as the above-mentioned manganese hydroxide, preferably, a water-soluble manganese compound such as manganese chloride or manganese nitrate is reacted with an excess amount of an alkaline compound such as sodium hydroxide, potassium hydroxide, or aqueous ammonia in water to obtain a nearly quantitative amount. Preferably, the manganese hydroxide is produced as a wet cake and the manganese hydroxide thus obtained is used as a wet cake.

The above-mentioned zirconium hydroxide and manganese hydroxide may be used by producing a wet cake of mixed hydroxide of zirconium and manganese.

The seed crystal of the manganese-doped barium zirconate used in the step (a) may be any seed crystal as long as it is represented by the composition formula (I). It is preferable that there be. When the average particle diameter of the seed crystal exceeds 2.0 μm, the resulting manganese-doped barium zirconate particles have a small specific surface area, low crystallinity, and do not have high catalytic activity as an organic matter decomposition catalyst. The lower limit of the average particle diameter of the seed crystal is usually 0.1 μm, although it is not particularly limited.

The seed crystal is preferably used in an amount of 1 to 20 parts by mole based on 100 parts by mole of the total number of manganese and zirconium contained in the first slurry. When the amount of the seed crystal used is less than 1 mole part per 100 mole parts of the total number of manganese and zirconium contained in the first slurry, it is difficult to obtain manganese-doped barium zirconate particles having a high specific surface area. be. On the other hand, even if a large amount of seed crystals exceeding 20 molar parts per 100 molar parts of zirconium in the zirconium hydroxide contained in the first slurry is used, the specific surface area of the resulting manganese-doped barium zirconate particles will decrease. There is no change, and thus the addition of such large amounts of seed crystals does not have a commensurate effect.

In particular, it is preferable to use the seed crystal in an amount of 1 to 10 mole parts based on 100 mole parts of the total number of manganese and zirconium contained in the first slurry.

The step (b) is a step of hydrothermally reacting the first slurry obtained in step (a) to obtain a reaction mixture containing manganese-doped barium zirconate particles as a reaction product as a second slurry. be. The temperature of this hydrothermal reaction is usually in the range of 120 to 300°C, preferably in the range of 130 to 250°C, and most preferably in the range of 150 to 200°C.

The second slurry contains manganese-doped barium zirconate particles produced by a hydrothermal reaction of barium hydroxide, zirconium hydroxide, and manganese hydroxide. In this case, even if barium hydroxide, zirconium hydroxide, and manganese hydroxide are subjected to a hydrothermal reaction with a Ba/(Zr+Mn) molar ratio of 1.0, the reactivity of barium is lower than that of zirconium or manganese. Since the Ba/(Zr+Mn) molar ratio in the manganese-doped barium zirconate obtained is usually lower than 1.0, in step (b), the reaction mixture obtained by the hydrothermal reaction contains: Unreacted barium remains as barium hydroxide and/or barium carbonate.

Therefore, in step (c), the second slurry obtained by the above hydrothermal reaction is treated with an acid such as nitric acid, and then washed with water to obtain manganese-doped barium zirconate particles. The unreacted barium is removed from the reactor as a water-soluble barium salt such as barium nitrate.

On the other hand, even if barium hydroxide, zirconium hydroxide, and manganese hydroxide are subjected to a hydrothermal reaction under conditions where the Ba/(Zr+Mn) molar ratio is higher than 1.0, hydroxide does not contribute to the organic matter decomposition catalyst activity. Barium and/or barium carbonate may remain as they are in the obtained manganese-added barium zirconate particles and have a detrimental effect on the organic matter decomposition catalyst activity per unit weight, so the Ba/(Zr+Mn) molar ratio In step (c), the second slurry obtained by the hydrothermal reaction is preferably treated with an acid and washed with water, as in the case where the .

Thus, after the second slurry is acid-treated, it is washed with water, and if necessary, filtered and dried to obtain single-phase manganese-added barium zirconate particles that do not contain unreacted barium as a foreign phase. I can do it.

The acid used in the acid treatment may be either an inorganic acid or an organic acid. Usually, nitric acid, hydrochloric acid, acetic acid, etc. are preferably used, and the acid treatment is performed so that the second slurry has a pH of about 5. Moreover, ion-exchanged water or pure water is preferably used for the water washing treatment. It is preferable that the water washing treatment is carried out until the electrical conductivity of the filtrate becomes 5 ms/m or less.

If the amount of barium in the manganese-doped barium zirconate particles obtained by the above method is deficient, that is, if the Ba/(Zr+Mn) molar ratio is less than 1, the barium is compensated for in the manganese-doped barium zirconate particles. In this way, manganese-doped barium zirconate particles having a desired Ba/(Zr+Mn) molar ratio can be obtained.

That is, for example, after a hydrothermal reaction, the resulting reaction mixture (solid) is filtered, treated with an acid, and washed with water to remove barium hydroxide dissolved in water from the reaction mixture. The Ba/(Zr+Mn) molar ratio of the reaction product obtained is analyzed, and then a barium compound is added to the reaction product as an additive to obtain the desired Ba/(Zr+Mn) molar ratio. /(Zr+Mn) molar ratio, and by sintering this, a manganese-doped barium zirconate sintered body having a desired Ba/(Zr+Mn) molar ratio can be obtained.

Here, the above additive has a low solubility in water, and furthermore, when the reaction mixture containing the additive is sintered, even if the additive is thermally decomposed, substances other than barium will be released. Those that do not remain in the sintered body, such as carbonates, organic acid salts, oxides, etc., are preferably used.

EXAMPLES The present invention will be explained in detail below by giving Examples and Comparative Examples regarding the manganese-doped barium zirconate particles according to the present invention, but the present invention is not limited to these Examples in any way. In addition, production examples of a mixed hydroxide of zirconium and manganese or each hydroxide used in the production of manganese-doped barium zirconate particles according to the present invention will be given.

Manufacturing example 1
(Production of wet cake of mixed hydroxide of zirconium and manganese)
Add 295.29 g of zirconium oxychloride octahydrate (manufactured by Yoneyama Pharmaceutical Co., Ltd.) and 18.62 g of manganese chloride tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to 2 L of ion-exchanged water in a glass beaker, and stir. Then, zirconium oxychloride octahydrate and manganese chloride tetrahydrate were dissolved in water to obtain a mixed aqueous solution of zirconium salt and manganese salt. Next, 79.98 g of sodium hydroxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 4 L of ion-exchanged water were added to a nylon beaker, and the mixture was stirred and dissolved to obtain an aqueous sodium hydroxide solution.

Using a tube pump, add the above mixed aqueous solution at a rate of 30 mL/min to a beaker equipped with another stirrer containing 1 L of ion-exchanged water, and add the above mixture to the beaker so that the pH becomes 10.5 to 11.5. Aqueous sodium hydroxide solution was added using a separate tube pump.

After the addition was completed, the mixture was stirred for 1 hour to obtain a slurry. The solid matter obtained by filtering this slurry was washed with ion-exchanged water until the water conductivity became 10 mS/m or less, and 1321.5 g of a wet cake of mixed hydroxide of zirconium and manganese (zirconium hydroxide concentration 10.3%, manganese hydroxide concentration 0.6%, Zr/(Zr+Mn) molar ratio 0.907, zirconium hydroxide yield 93%, manganese hydroxide yield 95%).

The above mixed hydroxide of zirconium and manganese easily absorbs moisture, and it is difficult to accurately weigh the concentration of each of the above hydroxides in the obtained wet cake. The concentration of hydroxide was determined as follows. That is, when the wet cake was heated to 500°C, the concentrations of zirconium and manganese in the oxide residue were determined, and these were converted to the respective hydroxides, that is, Zr(OH) ₄ and Mn(OH) ₂ . The concentration and yield of each hydroxide were determined. It was confirmed by X-ray diffraction that physically adsorbed water and hydroxyl groups were completely removed and oxides were formed by heating the cake to 500°C.

(Manufacture of seed crystals)
Put 51.25 g of the wet cake of the mixed hydroxide of zirconium and manganese into a titanium container, add 18.92 g of barium hydroxide octahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 0.0 g of ion-exchanged water. 1 L was added and stirred to form a slurry.

The titanium container was placed in an autoclave and heated at 200° C. for 2 hours to cause a hydrothermal reaction between the mixed hydroxide of zirconium and manganese and barium hydroxide. The obtained slurry was transferred to a polyethylene beaker equipped with a stirrer, a 0.2% aqueous nitric acid solution was added thereto to adjust the pH of the slurry to 5, and the slurry was stirred for 30 minutes. After 30 minutes, the pH of the slurry rose again, so 0.2% nitric acid aqueous solution was added to readjust the pH to 5.

The solid matter obtained by filtering this slurry was washed with ion-exchanged water until the washing water conductivity became 10 mS/m or less. After washing with water, the obtained cake was dried overnight in a dryer set at a temperature of 150°C, and seed crystal particles of manganese-doped barium zirconate represented by the composition formula BaZr _0.903 Mn _0.097 O _3-δ were added. Obtained.

0.11 g (0.00040 mol) of the thus obtained seed crystal particles was weighed into a 100 mL plastic container, and 8 mL of ion-exchanged water was added to form a slurry. After adding 8 mL of zirconia beads with a diameter of 1.0 mm to this slurry, it was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotation speed of 210 rpm for 1 hour to wet-pulverize the slurry. The beads were separated from the slurry using a sieve, the beads were washed with 2 mL of ion-exchanged water, and the wash water was returned to the slurry to give a total slurry volume of 10 mL. In this way, a pulverized slurry of seed crystals was obtained with an average particle diameter of 0.19 μm and a slurry concentration of 0.011 g/mL (0.00004 mol/mL).

Example 1
(Step (a))
In a titanium container, 51.25 g of the wet cake of mixed hydroxide of zirconium and manganese obtained in Production Example 1 and 18.92 g of barium hydroxide octahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were weighed. Add 0.09 L of ion-exchanged water, and add 10 mL of the seed crystal pulverized slurry obtained in Production Example 1 (0.00040 mol as seed crystal, to 100 mol parts of the total molar parts of zirconium and manganese in the first slurry). 1 mole part) was added thereto and stirred to prepare a first slurry.

(Step (b))
The titanium container was placed in an autoclave and heated at 200° C. for 2 hours to cause a hydrothermal reaction between the mixed hydroxide of zirconium and manganese and barium hydroxide in the presence of the crushed seed crystals.

(Step (c))
The slurry thus obtained was transferred to a polyethylene beaker equipped with a stirrer, a 0.2% aqueous nitric acid solution was added thereto to adjust the pH of the slurry to 5, and the slurry was stirred for 30 minutes. After 30 minutes, the pH of the slurry had risen again, so 0.2% nitric acid aqueous solution was further added to readjust the pH to 5.

This slurry was filtered, and the obtained solid material was washed with ion-exchanged water until the washing water conductivity became 10 mS/m or less. After washing with water, the obtained cake was dried overnight in a dryer set at a temperature of 150° C. to obtain manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.903 Mn _0.097 O _3-δ .

Example 2
0.33 g (0.0012 mol) of the seed crystal particles obtained in Production Example 1 was weighed into a 100 mL plastic container, and 8 mL of ion-exchanged water was added to form a slurry. After adding 8 mL of zirconia beads with a diameter of 1.0 mm to this slurry, it was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotation speed of 210 rpm for 1 hour to wet-pulverize the slurry. The beads were separated from the slurry using a sieve, the beads were washed with 2 mL of ion-exchanged water, and the wash water was returned to the slurry to give a total slurry volume of 10 mL. In this way, a pulverized slurry of seed crystals was obtained with an average particle diameter of 0.26 μm and a slurry concentration of 0.033 g/mL (0.00012 mol/mL).

The procedure was carried out in the same manner as in Example 1, except that 10 mL of the above-mentioned pulverized slurry of the seed crystals (0.0012 mol as the seed crystal, 3 mol parts based on 100 mol parts of the total zirconium and manganese in the first slurry) was used. As a result, manganese-doped barium zirconate particles having the compositional formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Example 3
1.1 g (0.0040 mol) of the seed crystal particles obtained in Production Example 1 were weighed into a 100 mL plastic container, and 8 mL of ion-exchanged water was added to form a slurry. After adding 8 mL of zirconia beads with a diameter of 1.0 mm to this slurry, it was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotation speed of 210 rpm for 1 hour to wet-pulverize the slurry. The beads were separated from the slurry using a sieve, the beads were washed with 2 mL of ion-exchanged water, and the wash water was returned to the slurry to give a total slurry volume of 10 mL. In this way, a pulverized slurry of seed crystals was obtained with an average particle diameter of 0.31 μm and a slurry concentration of 0.11 g/mL (0.00040 mol/mL).

The procedure was carried out in the same manner as in Example 1, except that 10 mL of the above-mentioned pulverized slurry of the seed crystals (0.0040 mol as the seed crystal, 10 mol parts based on the total 100 mol parts of zirconium and manganese in the first slurry) was used. As a result, manganese-doped barium zirconate particles having the compositional formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Manufacturing example 2
(Production of wet cake of mixed hydroxide of zirconium and manganese)
In the same manner as in Production Example 1, except that 257.87 g of zirconium oxychloride octahydrate (manufactured by Yoneyama Yakuhin Kogyo Co., Ltd.) and 39.53 g of manganese chloride tetrahydrate (manufactured by Nihon Kagaku Sangyo Co., Ltd.) were used. 1129.0 g wet cake of mixed hydroxide of zirconium and manganese (zirconium hydroxide concentration 10.5%, manganese hydroxide concentration 1.5%, Zr/(Zr+Mn) molar ratio 0.800, yield of zirconium hydroxide The yield of manganese hydroxide was 93% and the yield of manganese hydroxide was 95%. The zirconium hydroxide concentration and manganese hydroxide concentration in the wet cake and their respective yields were determined in the same manner as in Production Example 1.

(Manufacture of seed crystals)
Weigh out 37.62 g of the wet cake of the mixed hydroxide of zirconium and manganese into a titanium container, add 18.92 g of barium hydroxide octahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and ion exchange water. 0.1 L was added and stirred to form a slurry.

The titanium container was placed in an autoclave, and under the same conditions as in Example 1, a hydrothermal reaction and a slurry obtained by the hydrothermal reaction were subjected to pH adjustment, water washing, and drying. In this way, manganese-doped barium zirconate seed crystal particles having the composition formula BaZr _0.807 Mn _0.193 O _3-δ were obtained.

0.11 g (0.00040 mol) of this seed crystal particle was weighed out in a 100 mL plastic container, and 8 mL of ion-exchanged water was added to form a slurry. After adding 8 mL of zirconia beads with a diameter of 1.0 mm to this slurry, it was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotation speed of 210 rpm for 1 hour to wet-pulverize the slurry. The beads were separated from the slurry using a sieve, the beads were washed with 2 mL of ion-exchanged water, and the wash water was returned to the slurry to give a total slurry volume of 10 mL. In this way, a pulverized slurry of seed crystals was obtained with an average particle diameter of 0.25 μm and a slurry concentration of 0.011 g/mL (0.00004 mol/mL).

Example 4
Using 10 mL of the seed crystal pulverized slurry obtained in Production Example 2 (0.00040 mol as the seed crystal, 1 mol part per 100 mol parts of the total number of zirconium and manganese molar parts in the first slurry), A product having the composition formula _BaZr0. Manganese-doped barium zirconate particles represented by ₇₉₇ Mn _0.203 O _3-δ were obtained. FIG. 1 shows the powder X-ray diffraction pattern of the manganese-doped barium zirconate particles.

Example 5
0.11 g (0.00040 mol) of the seed crystal particles obtained in Production Example 1 were slurried and pulverized in the same manner as in Example 1 to obtain an average particle diameter of 0.23 μm and a slurry concentration of 0.011 g/mL (0.01 g/mL). A pulverized slurry of seed crystals with a concentration of 0.00004 mol/mL) was obtained. Using 10 mL of the above-mentioned pulverized slurry of the seed crystal (0.00040 mol as the seed crystal, 1 mol part per 100 mol parts of the total zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.901 Mn _0.099 O _3-δ were obtained in the same manner as in Example 1, except that the molar ratio (Zr+Mn) was 1.0.

Example 6
0.33 g (0.0012 mol) of the seed crystal particles obtained in Production Example 1 were slurried and ground in the same manner as in Example 2 to obtain an average particle diameter of 0.20 μm and a slurry concentration of 0.033 g/mL (0. A pulverized slurry of seed crystals of 0.00012 mol/mL) was obtained. Using 10 mL of the seed crystal pulverized slurry (0.0012 mol as the seed crystal, 3 mol parts based on 100 mol parts of the total zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.902 Mn _0.098 O _3-δ were obtained in the same manner as in Example 1, except that the molar ratio (Zr+Mn) was 1.0.

Example 7
1.1 g (0.0040 mol) of the seed crystal particles obtained in Production Example 1 were slurried and pulverized in the same manner as in Example 3, and the average particle diameter was 0.23 μm and the slurry concentration was 0.11 g/mL (0. A pulverized slurry of seed crystals of 0.00040 mol/mL) was obtained. Using 10 mL of the seed crystal pulverized slurry (0.0040 mol as the seed crystal, 10 mol parts based on 100 mol parts of the total number of zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.901 Mn _0.099 O _3-δ were obtained in the same manner as in Example 1, except that the molar ratio (Zr+Mn) was 1.0.

Example 8
0.11 g (0.00040 mol) of the seed crystal particles obtained in Production Example 1 were slurried and pulverized in the same manner as in Example 1 to obtain an average particle diameter of 0.26 μm and a slurry concentration of 0.011 g/mL (0.01 g/mL). A pulverized slurry of seed crystals with a concentration of 0.00004 mol/mL) was obtained. Using 10 mL of the above-mentioned pulverized slurry of the seed crystal (0.00040 mol as the seed crystal, 1 mol part per 100 mol parts of the total zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.902 Mn _0.098 O _3-δ were obtained in the same manner as in Example 1 except that the molar ratio (Zr+Mn) was 2.0.

Example 9
0.33 g (0.0012 mol) of the seed crystal particles obtained in Production Example 1 were slurried and ground in the same manner as in Example 2, with an average particle diameter of 0.21 μm and a slurry concentration of 0.033 g/mL (0. A pulverized slurry of seed crystals of 0.00012 mol/mL) was obtained. Using 10 mL of the seed crystal pulverized slurry (0.0012 mol as the seed crystal, 3 mol parts based on 100 mol parts of the total zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the composition formula BaZr _0.901 Mn _0.099 O _3-δ were obtained in the same manner as in Example 1, except that the molar ratio (Zr+Mn) was 2.0.

Example 10
1.1 g (0.0040 mol) of the seed crystal particles obtained in Production Example 1 were slurried and pulverized in the same manner as in Example 3 to obtain an average particle diameter of 0.24 μm and a slurry concentration of 0.11 g/mL (0.004 μm). A pulverized slurry of seed crystals of 0.00040 mol/mL) was obtained. Using 10 mL of the seed crystal pulverized slurry (0.0040 mol as the seed crystal, 10 mol parts based on 100 mol parts of the total number of zirconium and manganese in the first slurry), Ba/( Manganese-doped barium zirconate particles represented by the composition formula BaZr _0.901 Mn _0.099 O _3-δ were obtained in the same manner as in Example 1, except that the molar ratio (Zr+Mn) was 2.0.

Example 11
0.33 g (0.0012 mol) of the seed crystal particles obtained in Production Example 1 were slurried in the same manner as in Example 2, and 10 mL of zirconia beads with a diameter of 1.0 mm were added thereto. -5) and operated for 2 minutes at a rotational speed of 210 rpm to pulverize the slurry. Beads were removed from this slurry using a sieve to obtain a pulverized slurry of seed crystals with an average particle diameter of 1.83 μm and a slurry concentration of 0.033 g/mL (0.00012 mol/mL).

Same as Example 1 except that 10 mL of the above-mentioned pulverized slurry of seed crystals was used (0.0012 mol as the seed crystal, 3 mol parts based on 100 mol parts of the total zirconium and manganese in the first slurry). As a result, manganese-doped barium zirconate particles having the compositional formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Manufacturing example 3
(Production of wet cake of zirconium hydroxide)
295.29 g of zirconium oxychloride octahydrate (manufactured by Yoneyama Yakuhin Kogyo Co., Ltd.) was added to 2 L of ion-exchanged water in a glass beaker, and the mixture was stirred to dissolve the zirconium oxychloride octahydrate in the water. Next, 79.98 g of sodium hydroxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 4 L of ion-exchanged water were added to a nylon beaker, and the mixture was stirred and dissolved to obtain an aqueous sodium hydroxide solution.

Using a tube pump, add the above aqueous solution at a rate of 30 mL/min to a beaker equipped with another stirrer containing 1 L of ion-exchanged water, and add the above water to the beaker so that the pH becomes 10.5 to 11.5. Aqueous sodium oxide solution was added using a separate tube pump.

After the addition was completed, the mixture was stirred for 1 hour to obtain a slurry. The solid material obtained by filtering this slurry was washed with ion-exchanged water until the water conductivity became 10 mS/m or less, and 1669.0 g of a wet cake of zirconium hydroxide (zirconium hydroxide concentration 8.1 %, yield 93%). The zirconium hydroxide concentration and yield of the wet cake were determined in the same manner as in Production Example 1.

(Production of wet cake of manganese hydroxide)
98.1 g of manganese chloride tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 500 mL of ion-exchanged water in a glass beaker, and the mixture was stirred to dissolve the manganese chloride tetrahydrate in the water. Next, 79.98 g of sodium hydroxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 4 L of ion-exchanged water were added to a nylon beaker, and the mixture was stirred and dissolved to obtain an aqueous sodium hydroxide solution.

Using a tube pump, add the above aqueous solution at a rate of 30 mL/min to a beaker equipped with another stirrer containing 100 mL of ion-exchanged water, and add the above water to the beaker so that the pH becomes 10.5 to 11.5. Aqueous sodium oxide solution was added using a separate tube pump.

After the addition was completed, the mixture was stirred for 1 hour to obtain a slurry. The solid material obtained by filtering this slurry was washed with ion-exchanged water until the water conductivity became 10 mS/m or less, and 535.8 g of a wet cake of manganese hydroxide (manganese hydroxide concentration 7.8 %, yield 95%). The manganese hydroxide concentration and yield of the wet cake were determined in the same manner as in Production Example 1.
I got it.

Example 12
0.11 g (0.00040 mol) of the seed crystal particles obtained in Production Example 1 were slurried and pulverized in the same manner as in Example 1 to obtain an average particle diameter of 0.23 μm and a slurry concentration of 0.011 g/mL (0.01 g/mL). A pulverized slurry of seed crystals with a concentration of 0.00004 mol/mL) was obtained. Using 10 mL of this seed crystal slurry (0.00040 mol as seed crystal, 1 mol part per 100 mol parts of total zirconium and manganese in the first slurry), the zirconium hydroxide obtained in Production Example 3 was used. Except that 40.62 g of manganese hydroxide cake, 2.57 g of manganese hydroxide cake obtained in Production Example 3, and 18.92 g of barium hydroxide octahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were used. In the same manner as in Example 1, manganese-doped barium zirconate particles having the compositional formula BaZr _0.902 Mn _0.098 O _3-δ were obtained.

Comparative example 1
(Production of manganese-doped barium zirconate particles by solid phase method)
Barium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 85.58 g, zirconium oxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 49.21 g, and manganese carbonate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 5.22 g 210 mL of ion-exchanged water and 140 mL of zirconia beads having a diameter of 3.0 mm were placed in a 500 mL plastic container to obtain a slurry.

The plastic container was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotational speed of 180 rpm for 120 minutes to wet-pulverize the slurry. The beads were removed from the resulting slurry using a sieve, and the resulting slurry was dried overnight in a dryer set at a temperature of 150°C, and then dried in a sample mill (SK-10, manufactured by Kyoritsu Riko Co., Ltd.). It was pulverized to obtain a raw material powder.

The raw material powder obtained above was filled into an alumina crucible and fired in an electric furnace at a temperature of 1200° C. in an air atmosphere for 2 hours. The obtained fired product was pulverized using the sample mill described above to obtain manganese-doped barium zirconate particles represented by the compositional formula BaZr _0.904 Mn _0.096 O _3-δ .

Comparative example 2
(Production of manganese-doped barium zirconate particles by solid phase method)
Barium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 86.41 g, zirconium oxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 43.25 g, and manganese carbonate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 10.33 g Manganese-doped barium zirconate particles having the compositional formula BaZr _0.809 Mn _0.191 O _3-δ were obtained in the same manner as in Comparative Example 1, except that . FIG. 1 shows the powder X-ray diffraction pattern of the manganese-doped barium zirconate particles. It has been shown that the above manganese-doped barium zirconate particles contain a heterophase.

Comparative example 3
(Production of barium zirconate particles by solid phase method)
Comparative Example 1 except that 86.12 g of barium carbonate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 53.88 g of zirconium oxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were used instead of manganese carbonate. Similarly, barium zirconate particles represented by the compositional formula BaZrO ₃ were obtained.

Production example 4
(Production of wet cake of zirconium hydroxide)
Add 295.44 g of zirconium oxychloride octahydrate (manufactured by Yoneyama Pharmaceutical Co., Ltd.) to 1.8 L of ion-exchanged water in a glass beaker, and stir to dissolve the zirconium oxychloride octahydrate in water to obtain an aqueous solution. . Next, 79.98 g of sodium hydroxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 4 L of ion-exchanged water were added to a nylon beaker, and the mixture was stirred and dissolved to obtain an aqueous sodium hydroxide solution.

Using a tube pump, add the above aqueous solution at a rate of 30 mL/min to a beaker equipped with another stirrer containing 1 L of ion-exchanged water, and add the above water to the beaker so that the pH is 8.5 to 9.5. Aqueous sodium oxide solution was added using a separate tube pump.

After the addition was completed, the mixture was stirred for 1 hour to obtain a slurry. The solid material obtained by filtering this slurry was washed with ion-exchanged water until the water conductivity became 10 mS/m or less, and 1564.8 g of a wet cake of zirconium hydroxide (zirconium hydroxide concentration 8.5 %, yield 91%). The zirconium hydroxide concentration and yield of the wet cake were determined in the same manner as in Production Example 1.

(Manufacture of seed crystals)
Barium zirconate represented by the composition formula BaZrO ₃ was prepared in the same manner as in Example 1 except that 61.08 g of the above zirconium hydroxide cake and 18.92 g of barium hydroxide octahydrate were used without using manganese carbonate. Seed crystal particles were obtained.

0.11 g (0.00040 mol) of the above seed crystal particles were weighed into a 100 mL plastic container, and 8 mL of ion-exchanged water was added to form a slurry. After adding 8 mL of zirconia beads with a diameter of 1.0 mm to this slurry, it was placed in a planetary ball mill (P-5 manufactured by Fritsch) and operated at a rotation speed of 210 rpm for 1 hour to wet-pulverize the slurry. The beads were separated from the slurry using a sieve, the beads were washed with 2 mL of ion-exchanged water, and the wash water was returned to the slurry to give a total slurry volume of 10 mL. In this way, a pulverized slurry of seed crystals was obtained with an average particle diameter of 0.25 μm and a slurry concentration of 0.011 g/mL (0.00004 mol/mL).

Comparative example 4
Using 8 mL of the seed crystal slurry obtained in Production Example 4 (0.00032 mol as seed crystal, 1 mol part per 100 mol parts of zirconium in the first slurry)), zirconium hydroxide cake 61 Barium zirconate particles represented by the compositional formula BaZrO ₃ were obtained in the same manner as in Example 1 except that 18.92 g of barium hydroxide octahydrate and 18.92 g of barium hydroxide octahydrate were used.

Comparative example 5
Seed crystals of manganese-doped barium zirconate represented by the compositional formula BaZr _0.904 Mn _0.096 O _3-δ were prepared in the same manner as in Example 1, except that the hydrothermal reaction was carried out in the absence of seed crystals. Particles were obtained.

Comparative example 6
0.11 g (0.00040 mol) of the seed crystal particles obtained in Production Example 1 were slurried in the same manner as in Example 1, with an average particle diameter of 3.99 μm and a slurry concentration of 0.011 g/mL (0.00004 A seed crystal slurry of mol/mL) was obtained. The same procedure as in Example 1 was carried out, except that 10 mL of the above seed crystal slurry (0.00040 mol as the seed crystal, 1 mol part per 100 mol parts of the total number of zirconium and manganese in the first slurry) was used. Manganese-doped barium zirconate particles having the compositional formula BaZr _0.904 Mn _0.096 O _3-δ were obtained.

Comparative example 7
0.33 g (0.0012 mol) of the seed crystal particles obtained in Production Example 1 was slurried in the same manner as in Example 2, with an average particle diameter of 3.99 μm and a slurry concentration of 0.033 g/mL (0.00012 mol). /mL) of seed crystal slurry was obtained. The same procedure as in Example 1 was carried out, except that 10 mL of the above seed crystal slurry (0.0012 mol as the seed crystal, 3 mol parts per 100 mol parts of the total zirconium and manganese in the first slurry) was used. Manganese-doped barium zirconate particles having the composition formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Comparative example 8
1.1 g (0.0040 mol) of the seed crystal particles obtained in Production Example 1 were slurried in the same manner as in Example 3, with an average particle diameter of 3.99 μm and a slurry concentration of 0.11 g/mL (0.00040 mol). /mL) of seed crystal slurry was obtained. The same procedure as in Example 1 was carried out, except that 10 mL of the above seed crystal slurry (0.0040 mol as the seed crystal, 10 mol parts per 100 mol parts of the total zirconium and manganese in the first slurry) was used. Manganese-doped barium zirconate particles having the composition formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Comparative example 9
1.1 g (0.0040 mol) of the seed crystal particles obtained in Production Example 1 were slurried in the same manner as in Example 3, and 10 mL of zirconia beads with a diameter of 1.0 mm were added thereto. -5) and operated at a rotational speed of 210 rpm for 1 minute and 15 seconds to pulverize the slurry. Beads were removed from this slurry using a sieve to obtain a pulverized slurry of seed crystals with an average particle diameter of 2.10 μm and a slurry concentration of 0.11 g/mL (0.00040 mol/mL).

The same procedure as in Example 1 was carried out, except that 10 mL of the above seed crystal slurry (0.0040 mol as the seed crystal, 10 mol parts per 100 mol parts of the total zirconium and manganese in the first slurry) was used. Manganese-doped barium zirconate particles having the composition formula BaZr _0.903 Mn _0.097 O _3-δ were obtained.

Comparative example 10
Instead of using a mixed hydroxide cake of zirconium and manganese, zirconium oxychloride octahydrate (manufactured by Yoneyama Pharmaceutical Co., Ltd.) and manganese chloride tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were used instead. When hydrothermal synthesis was carried out in the same manner as in Example 1 except for this, the desired manganese-doped barium zirconate particles were not obtained.

Various methods for measuring the manganese-added barium zirconate particles or barium zirconate particles obtained in the above Examples and Comparative Examples will be described below. In the following, (manganese-doped) barium zirconate means manganese-doped barium zirconate or barium zirconate.

Method for evaluating organic substance decomposition catalytic activity 0.2 g of carbon black (manufactured by Sigma-Aldrich, CP) was added to 1.0 g of each (manganese-added) barium zirconate powder obtained in the above examples and comparative examples, and the mixture was placed in a mortar. A sample was prepared by mixing.

10 mg of the above sample was subjected to thermogravimetric analysis using a thermal analyzer ThermoPlus EVO TG/DTA/H manufactured by Rigaku Co., Ltd. under the conditions of a heating rate of 10°C/min, a measurement atmosphere of 10% oxygen, and a gas flow rate of 0.4 L/min. went. As an index of the thermal decomposition behavior of organic carbon black, the peak top temperature was determined based on the differential curve of thermogravimetric change.

The peak top temperature according to the differential curve of thermogravimetric change is considered to be the temperature at which the combustion of carbon black is most active, that is, the temperature at which the catalyst activity is maximized. It can be said that the lower the peak top temperature, the more combustion effect can be obtained with less energy.

(Manganese added) Average particle diameter of barium zirconate seed crystal particles (Manganese added) Barium zirconate seed crystal particles were used as a sample, sodium hexametaphosphate was added as a dispersant, dispersed with an ultrasonic homogenizer, and laser diffraction was performed. - Measurement was performed using a scattering particle size distribution measuring device (LA-950V2 manufactured by Horiba, Ltd.) under the following conditions.

Particle refractive index: 2.4
Solvent refractive index: 1.333
The volume median diameter obtained in the above particle size distribution measurement was defined as the average particle diameter.

(Manganese added) Method for measuring the composition ratio of barium zirconate particles (pretreatment)
0.6 g of barium zirconate (with manganese added) was weighed into a platinum crucible, and then 6.0 g of lithium tetraborate (Fuji Film Wako Pure Chemical Industries, Ltd.) was weighed out. 25.0 g of potassium bromide (Fuji Film Wako Pure Chemical Industries, Ltd.) was weighed into a beaker, 75 mL of ion-exchanged water was added, and the mixture was stirred and dissolved using a glass rod to obtain a 25% potassium bromide aqueous solution. 40 μL of this 25% potassium bromide aqueous solution was taken with a micropipettor and added to a platinum crucible in which barium zirconate (with manganese added) and lithium tetraborate had been weighed.

After attaching the platinum crucible to a bead & fuse sampler (manufactured by Amena Tech Co., Ltd., model TK-4100 high-frequency melting equipment), the contents of the crucible were heated and melted at 1000°C, and a glass bead sample of barium zirconate (with manganese added) was prepared. I got it.

(composition ratio measurement)
The molar concentration of each element in the glass bead sample was measured by wavelength-dispersive fluorescent X-ray analysis using a fluorescent X-ray device (Rigaku Corporation, ZSX Primus II), and the molar ratio was calculated by the calibration curve method. The measurement conditions are as follows.

Sample spin: Yes Target: Rh, 50KV-60mA

Method for measuring the specific surface area of barium zirconate particles (added with manganese) The specific surface area of the obtained barium zirconate (added with manganese) was determined by BET using a specific surface area measuring device (Macsorb HM-1220, manufactured by Mountech Co., Ltd.). Measured by flow method. Pure nitrogen was used as the adsorption gas, and the temperature was maintained at 230°C for 30 minutes.

Method for measuring the X-ray diffraction pattern of (manganese-added) barium zirconate particles The X-ray diffraction pattern of the obtained (manganese-added) barium zirconate particles was measured using a powder X-ray diffractometer (manufactured by Rigaku Co., Ltd., sample horizontal type Measurement was performed using an X-ray diffractometer (RINT-TTRIII) under the following conditions.

Optical system: Parallel beam optical system (long slit: PSA200/aperture angle: 0.057°)
Tube voltage: 50kV
Current: 300mA
Measurement method: Parallel method (continuous)
Measurement range (2θ): 10~70°
Sampling width: 0.04°
Scan speed: 5°/min

Method for measuring the crystallite diameter of (manganese-added) barium zirconate particles From the half-value width of the diffraction line for the (110) plane of the perovskite phase in the X-ray diffraction pattern of (manganese-added) barium zirconate particles measured by the method described above. The crystallite diameter of the (manganese-added) barium zirconate particles was calculated using Scherrer's equation.

Crystallite diameter=K×λ/βcosθ
K: Scherrer constant (=0.94)
λ: X-ray wavelength (Cu-Kα ray 1.5418 Å)
β: Half width (in radians)
θ: Bragg angle (1/2 of the diffraction angle 2θ)

Tables 1 and 2 show the reaction conditions in the above Examples and Comparative Examples as well as the physical properties of the obtained (manganese-added) barium zirconate particles.

As shown in the examples in Tables 1 and 2, the manganese-doped barium zirconate particles according to the present invention obtained by the hydrothermal method all have a large specific surface area, are fine, and have a crystallite diameter/specific surface area equivalent particle diameter. is close to 1, the particles are highly crystalline, do not contain foreign phases, and are single-phase particles.

In particular, as shown in the powder X-ray diffraction pattern of manganese in Figure 1, the manganese-doped barium zirconate particles according to Example 4 do not contain any foreign phase, even though the zirconium substitution ratio is 20 mol%. , is single phase.

Such manganese-doped barium zirconate particles according to the present invention have high catalytic activity as an organic matter decomposition catalyst. That is, as described above, the peak top temperature according to the differential curve of thermogravimetric change is about 100° C. lower than that of manganese-added barium zirconate particles according to a comparative example described later, and a combustion effect can be obtained with less energy.

On the other hand, the barium zirconate particles (with manganese added) according to the comparative example generally do not have high catalytic activity as an organic matter decomposition catalyst, regardless of the difference in the production method between the hydrothermal method and the solid phase method.

More specifically, Comparative Examples 1 to 3 are barium zirconate particles (with manganese added) obtained by a solid phase method, and in particular, the barium zirconate particles with manganese added according to Comparative Example 2 have a manganese substitution ratio of Zr of 20. It was close to mol% and contained a different phase. In addition, compared to the barium zirconate particles of Comparative Example 3 that do not contain Mn, the manganese-added barium zirconate particles of Comparative Examples 1 and 2 have lower crystallinity and relatively high specific surface areas, but they are also catalysts for organic matter decomposition. The catalytic activity is almost the same as that of Comparative Example 3.

Comparative Examples 4 to 9 show barium zirconate particles (with manganese added) obtained by a hydrothermal method. Comparative Example 4 shows the results of barium zirconate particles that do not contain manganese, and although the crystallinity is relatively high, it contains a different phase and has low catalytic activity as an organic substance decomposition catalyst.

In Comparative Example 5, manganese-added barium zirconate particles were obtained in the same manner as in Example 1 except that no seed crystal was used, but the specific surface area was small and the catalytic activity as an organic matter decomposition catalyst was low. .

In Comparative Examples 6 to 9, the average particle size of the seed crystals used was too large, resulting in a small specific surface area and a low catalytic activity as an organic substance decomposition catalyst.

Claims (2)

Compositional formula (I)
BaZr _1-x Mn _x O _3-δ
(In the formula, x is a number satisfying 0.08≦x≦0.25, and δ indicates the amount of oxygen vacancies.)
Manganese-added barium zirconate particles, which are represented by the following formula, have a crystallite diameter/specific surface area equivalent particle diameter in the range of 0.455 to 1.090 , and have a specific surface area of 8.2 m ² /g or more. An organic matter decomposition catalyst comprising the manganese-doped barium zirconate particles according to claim 1 .

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