JPH0268144A - Preparation of catalyst for hydrogenating reaction - Google Patents

Abstract

PURPOSE:To obtain a metal supported oxide composition ultrafine particle catalyst controlled in the physical properties and activity thereof and excellent in life by spraying a solution containing a metal element becoming a carrier and a metal element becoming an active seed in a heated oxidizing atmosphere and subsequeutly reducing the formed particles. CONSTITUTION:A metal element becoming a carrier such as Zr, Al or Ti and a metal salt becoming an active seed such as Ni, Cu or Fe are dissolved in water or in a water-containing solvent and this metal element-containing solution is sprayed into a heated oxidizing atmosphere to obtain ultrafine metal oxide particles having a spherical or hollow spherical shape and a particle size of about 1mum or less. Subsequently, these particles are subjected to reducing treatment in a hydrogen atmosphere and the metal oxide becoming the active seed in the ultrafine metal oxide particles is reduced to obtain a metal supported oxide composite ultrafine particle catalyst. This catalyst has high activity and durability and suppresses side reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a catalyst for a hydrogenation reaction, and more particularly, to a method for producing a catalyst for a hydrogenation reaction comprising ultrafine metal-supported oxide composite particles.

BACKGROUND ART Metal fine particles have recently been rapidly used in the fields of electronic materials, magnetic materials, optical materials, ceramics, and the like. Various attempts have been made to utilize ultrafine metal particles as catalyst materials. For example, a metal with a particle size of several tens to hundreds of particles (several 10-3 to several 10-2 μm) prepared by a chemical method, a physical method, or a combination thereof is suspended in a reaction solution. There is an attempt to use it as a reciprocal catalyst [Noda et al., 8th Edition, 1984.1017E. Also, particle size 10-10
Various studies have also been conducted on metal-supported catalysts, which are mainly used in solid-gas phase heterogeneous reactions, in which metal particles are dispersed and supported on the surface of a support such as a metal oxide with a large surface area [for example, Takasu et al. et al., 8th edition, 1984.1o17E.

In general, the activity of a solid catalyst increases as the surface area of the active ingredient increases. Ultrafine metal particle catalysts have a sufficiently small particle size of the metal that serves as the active component, so the surface area of the active component is large.
As a result, the catalyst is characterized by a large number of active sites per unit weight of the catalyst. Furthermore, ultrafine metal particle catalysts are attracting a lot of attention as catalysts with high activity and high selectivity because they tend to exhibit specific interactions with carriers.

[Problems to be Solved by the Invention] However, although ultrafine metal particles have excellent characteristics as catalysts for chemical reactions as described above and are an interesting catalyst material, they have the disadvantage that they are not necessarily easy to prepare. . In other words, it is necessary to prepare ultrafine metal particle catalysts by accurately controlling the particle size and distribution of the metal particles depending on the purpose of the reaction, but it is difficult to precisely control the particle size and distribution of the metal particles. It's not easy.

Further, since the metal ultrafine particle catalyst has high surface reactivity, side reactions are likely to occur and durability is relatively poor. In particular, with metal-supported catalysts used under relatively high temperature conditions such as in solid-gas phase heterogeneous reactions, deterioration of the metal-supported catalyst may occur due to fusion between ultrafine metal particles, sintering, reaction with the support, etc. Easy to wake up. However, conventionally, it has been difficult to prepare a catalyst that maintains high surface reactivity, suppresses side reactions, and has good durability.

Therefore, an object of the present invention is to provide a metal-supported oxide that can easily control the physical properties and activity of the catalyst and has an excellent lifetime.
An object of the present invention is to provide a method capable of producing a composite ultrafine particle catalyst.

[Means for Solving the Problems] The present invention involves spraying a solution containing at least one type of metal element to be a carrier and one or more types of metal elements to be an active species into a heated oxidizing atmosphere, and then spraying the resulting oxide into a heated oxidizing atmosphere. The present invention relates to a method for producing a hydrogenation reaction catalyst including reduction treatment.

According to the present invention, a highly active and durable metal-supported oxide composite ultrafine particle catalyst can be produced extremely easily.

The present invention will be explained below.

Examples of the metal element to serve as an active species used in the present invention include metal elements such as Ni, Cu, Fe5Co, Cr, Mo, and Ag, with Ni being particularly preferred. These metal elements include inorganic salts such as nitrates and sulfates, halides such as chlorides and acid chlorides,
Used as organic acid salts such as acetates and oxalates in solutions sprayed into heated oxidizing atmospheres.

On the other hand, as a metal element to be a carrier, for example, Zr5
Examples include metal elements such as At and Ti5Si.

These metal elements are used as inorganic salts such as nitrates, sulfates, chlorides, or acid chlorides, and organic acid salts such as formates, acetates, and oxalates in a solution sprayed into a heated oxidizing atmosphere.

These metal salts and the like are dissolved in water or a solvent containing water and used for catalyst preparation. Note that the hydrogen ion concentration is adjusted if necessary during dissolution. Further, during dissolution, an organic solvent such as alcohol or acetone may be added. According to the method of the present invention, by changing the mixing ratio of the metal element to serve as a carrier and the metal element to serve as an active species contained in a solution, it is possible to easily and accurately add active metals as desired. The loading amount can be changed. The mixing ratio (atomic ratio) of the metal element to serve as a carrier and the metal element to serve as an active species contained in the solution is, for example, 100:1.
-4:1, preferably 30:1 - 6:1 is suitable. Furthermore, by appropriately selecting the concentrations of the metal element to serve as a support and the metal element to serve as an active species in the solution, it is possible to easily adjust the particle size of the ultimately obtained metal-supported oxide composite ultrafine particle catalyst. can. The concentration of the metal element to be a carrier and the metal element to be an active species in the solution is, for example, 0.01 to 5 mol/j! , preferably 0.03 to 1 mol/j! It is appropriate to

The thus prepared solution containing the metal element to serve as a carrier and the metal element to serve as an active species is sprayed into a heated oxidizing atmosphere. For example, a tubular reactor is used for thermal oxidation. This reaction device consists of a droplet insertion section for a solution containing the metal element, a reaction section that forms a heated oxidizing atmosphere, and a recovery section that recovers the produced ultrafine particle composite metal oxide. A solution (usually an aqueous solution) containing a metal element to serve as a carrier and a metal element to serve as an active species is sprayed in the form of small droplets to the reaction zone together with a gas containing oxygen. As oxygen-containing gas it is usually convenient to use air. Although the temperature of the reaction section varies depending on the type of metal, it is appropriate to set it to, for example, 300 to 1500°C, preferably 500 to 1200°C. The solution containing the metal element sprayed into the reaction section is instantaneously evaporated, dried, reacted, fired, etc. in the presence of an oxygen-containing gas to produce oxide particles. When a solution is sprayed, water in the solution rapidly evaporates, causing volumetric expansion, so it is desirable to maintain the reaction area at reduced pressure. Furthermore, it is desirable to maintain the pressure at reduced pressure in order to prevent fusion between the generated metal oxide particles.

There is no particular limit to the degree of pressure reduction, but for example, about 20 to 7
Q It is appropriate to set it to Qtorr. The generated particulate composite metal oxide is collected by a filter provided at the outlet of the reaction section.

In the manner described above, ultrafine metal oxide particles having a particle size of 1 μm or less and having a true spherical shape or a hollow spherical shape are obtained. The obtained ultrafine metal oxide particles are then subjected to a reduction treatment. An example of the reduction process is as follows. The ultrafine metal oxide particles obtained by the above method are packed into a flow-type or batch-type reactor, and reduced in a hydrogen atmosphere at 300 to 600°C for 0.5 to 30 hours, preferably 1 to 10 hours.

There is no particular limit to the pressure at that time. In this way, part or all of the metal oxide that is to become an active species in the metal oxide ultrafine particles is reduced to obtain a metal-supported oxide composite ultrafine particle catalyst.

The metal supported oxide composite ultrafine particle catalyst obtained by the method of the present invention contains Ni, Cu, Fe, Co, Cr, Mo and A
Active metals such as ZrO2, A1□03, Tie, etc.
These are so-called submicron-order fine particles with a particle size of 1 μm or less that are uniformly held on the surface and inside of a structure such as a metal oxide such as SiO□. The active metal component is retained in the carrier in the form of a solid solution or highly dispersed composite oxide during reaction and firing, and is then subjected to reduction treatment to form a metal/metal oxide composite. It should be noted that, without intending to be bound by theory, the active metal component of the catalyst according to the present invention can be formed at the same time as a single metal oxide or multi-component metal composite oxide such as Zr0z, Al2O3, T102.5i02, etc., which serves as a support. Since the active metal species are taken into the surface and inside of the carrier, they are homogeneously dispersed in the carrier. By reducing the active metal species, their grain growth is suppressed, and the active metal species are highly dispersed in clusters on the ultrafine carrier. It is thought that it has stabilized.

As a result, the catalyst according to the invention exhibits homogeneous and excellent activity, stability and durability.

The metal-supported oxide composite ultrafine particle catalyst prepared by the method described above is optimal as a catalyst for hydrogenation reactions. For example, aliphatic unsaturated hydrocarbons (e.g. ethylene,
propylene, butene, butadiene, isoprene, etc.), alicyclic unsaturated hydrocarbons (e.g., cyclopentene, cyclohexene, methylcyclohexene, cyclopentadiene, etc.), and aromatic hydrocarbons having unsaturated substituents in their side chains (e.g., , styrene, phenylacetylene, etc.).

The type of hydrogenation reaction may be either batchwise or continuous, and the reaction conditions include a reaction temperature of -30 to 200℃.
℃ is appropriate, and the reaction pressure is reduced to 50 kg.
/cd is appropriate. The reaction time can be selected arbitrarily. Additionally, a solvent or diluent inert to hydrogen and unsaturated hydrocarbons (e.g. methanol, ethanol, etc.) may be used during the reaction.
-hexane, cyclohexane, benzene, nitrogen gas, carbon dioxide gas, etc.) can also be used.

[Effects of the Invention] According to the method of the present invention, it is possible to obtain a homogeneous hydrogenation reaction catalyst having excellent low-temperature activity and long life.

The method of the present invention is an extremely easy method in which the sprayed microdroplets are fired in air or an oxygen stream, and then the obtained oxide is subjected to a reduction treatment. Furthermore, according to the method of the present invention, the catalyst particle diameter and the amount of active metal supported can be easily adjusted.

[Example code] The present invention will be explained in more detail below with reference to Examples.

Example 1 0.5 mol/1 Z r O(N 03)2
・2 H20 aqueous solution and 0.093 mol/(l of N
i (NO3)2' 6820 aqueous solution was mixed in a ratio of 1=1. Using an ultrasonic vibrator, the mixed aqueous solution of the metals was made into a mist and introduced together with air into a quartz reaction tube having an inner diameter of 25 mm and a length of 1 m. The reaction tube is divided into a front stage and a rear stage.
The temperature is 600℃ for the evaporation and drying sections before and after, and 100℃ for the rear reaction section.
The temperature was 0°C. The system was maintained at approximately 20 Qtorr, and the generated nickel-supported oxide composite ultrafine particles (hereinafter 5-Ni0/
(abbreviated as ZrCh) was collected by a filter provided at the outlet of the reaction tube.

A secondary electron image taken using a scanning electron microscope shows that the particles produced are perfectly spherical with smooth surfaces (see the photo in Figure 1).
The results of measuring the particle size distribution are shown in Table 1. In addition, the obtained 5-Ni0/Zr0h was heated in a hydrogen flow of 140 r
nf! /min, a heating rate of 10°C/min, and a measurement temperature range of 30-1000°C. The results of a temperature-promoted reaction test (TPR) using hydrogen showed that the nickel-supported oxide obtained by the impregnation method shown in Comparative Example 1 described below Ultrafine particles (i-Ni0/
ZrOH) showed clearly different behavior. That is,
In S-NiO/ZrO2, a peak of water production due to reduction of Ni oxide was observed at around 300°C, which is about 100°C higher than in 1-Ni0/ZrCh.

Example 2 0.5 mol/1 Z r O(NOs)2.2
H20 aqueous solution and 0.0.5 mol/R of N1 (
N 03) 2 .5 H2Q aqueous solution was mixed in l:1 ratio. Using the same reaction apparatus as in Example 1, the reaction was carried out under the same conditions as in Example 1 to obtain N1-supported oxide composite ultrafine particles.

A secondary electron image using a scanning electron microscope showed that the shape of the obtained Ni-supported oxide composite ultrafine particles was a perfect sphere with a smooth surface, and the results of measuring the particle size distribution were as shown in Table 1. there were.

Example 3 0.5 mol/f A I (NO3)2 ・9 H
20 aqueous solution and 0.04 mol/1 N 1 (N
03) 2.6 H20 aqueous solution was mixed at a ratio of 2:1. Using the same reaction apparatus as in Example 1, the reaction was carried out under the same conditions as in Example 1 to obtain Ni-supported oxide composite ultrafine particles (hereinafter referred to as S-N i O/A 1203).

A secondary electron image taken by a scanning electron microscope (see the photograph in Figure 2) showed that the shape of the obtained Ni-supported oxide composite ultrafine particles was truly spherical, and the results of measuring the particle size distribution showed that
It was as shown in Table 1.

Example 4 Dissolve TiC1< in 2N MCI to make 0.125 mo
A solution of l/47 was prepared. Apart from this, Ni (:l.

Prepare an O,L 25 mat/l aqueous solution of
Mixed 8:1 with i/HCI solution. The same reaction apparatus as in Example 1 was used, and the temperature conditions were 600 °C for the evaporation and drying parts.
The temperature of the reaction section was 800°C.

The obtained Ni-supported oxide composite ultrafine particles (hereinafter referred to as S-N i
The secondary electron image (see the photograph in Figure 3) of O/TiO2) by scanning electron microscope shows that the shape is truly spherical, and the results of measuring the particle size distribution are as shown in Table 1. It was on the street.

Example 5 5-Ni○/ZrChlOOmg prepared in Example 1 was charged into a closed circulation reactor, heated to 300° C. while degassing, and held at this temperature for 1 hour.

Next, 3 Q Qtorr of hydrogen was introduced at the same temperature, and 1
．． After holding for 5 hours, it was cooled to 0°C. Next, cis-2-butene and hydrogen were introduced at 300 torr each and mixed for 1 hour, and then the reaction rate of the hydrogenation reaction was determined at 0°C. Table 2 shows the reaction rate (turnover frequency, mmol·g-car'·lTl1 rho1) per surface metal based on the reaction rate and the number of active sites determined by another carbon monoxide and hydrogen adsorption test. Compared to the results of Comparative Example 2, several hundred times more activity was observed.

As a result of comparing the X-ray diffraction patterns before and after hydrogen reduction, the nickel-supported oxide composite ultrafine particle catalyst after hydrogen reduction showed that N
I was sure that the iO peak had disappeared.

Example 6 s-N io/Z rO20.5g prepared in Example 2
was charged into a glass continuous flow reactor, and reduced at 400° C. in a hydrogen stream for 2 hours.

Next, a hydrogenation reaction of cis-2-butene was carried out by flowing cis-2-butene and hydrogen at 60°C for 120 hours at a molar ratio of 1:5 and a space velocity (GH3V) of 300 h-1.

As a result, the conversion rate to butane was 99.8% on average from the start of the reaction up to 10 hours, 99.5% on average from 10 to 30 hours, and 99.5% on average from 30 to 50 hours.
1%, average 99.0% from 50 hours to 80 hours, 8
The average durability from 0 to 120 hours was 98.5%, and the durability of the catalyst was extremely good.

Example 7 s-N i O/A 12030 prepared in Example 3.
5 g was charged into the same reaction apparatus as in Example 6, and hydrogen reduction was performed under the same conditions as in Example 6. Next, a hydrogenation reaction of cis-2-butene was carried out under the same conditions as in Example 6. As a result, the average conversion rate to butane from the start of the reaction to 10 hours was 99.9%.

Example 8 sN i O/T i020 prepared in Example 4
．． 5 g was charged into the same reactor as in Example 6, and
Hydrogen reduction was performed under the same conditions as above. Next, hydrogenation reaction of cis-2-butene was carried out under the same conditions as in Example 6.

As a result, the average conversion rate to butane from the start of the reaction to 10 hours was 99.4%.

Comparative Example 1 Using the same reaction apparatus as Example 1, 0.093 mol
/j! 5 mol/12 of Z r O(NO3
)2.2 Only the H20 aqueous solution was treated under the same conditions as in Example 1.

The obtained ZrCh particles were dispersed in distilled water, and the nickel concentration was 0.093 mol/j2 so that the nickel concentration was 15 wt%.
An aqueous solution of N i (NO3)2'6H20 was added thereto, and the mixture was heated, evaporated, and dried while stirring. Next, it was fired at 450° C. for 4 hours in an air atmosphere using an electric furnace. In this way, nickel-supported metal oxide ultrafine particles (hereinafter abbreviated as 1-Ni0/ZrO2) were obtained by the impregnation method.

The obtained secondary electron image of the 1-Nip/ZrCh obtained by a scanning electron microscope (see the photograph in FIG. 4) was perfectly spherical, but showed a rough surface that was thought to be due to metal impregnation. The results of measuring the particle size distribution are shown in Table 1. Also,
The obtained 1-N10/ZrO2 was subjected to a temperature-programmed reaction test (TPR) using the same reaction apparatus and conditions as in Example 1. As a result, 2
A water production peak was observed around 00°C.

Comparative Example 2 After hydrogen reduction of iN iO/Zr 02 prepared in Comparative Example 1 using the same reaction apparatus as in Example 3 and under the same conditions as in Example 3, hydrogenation of cis-2-butene was performed. The reaction was carried out.

Reaction rate per surface metal (turnover frequency, mrnol -g-cat-' -+++
in-') are shown in Table 2.

No. figure

[Brief explanation of the drawing]

1 to 4 are photographs showing the particle structure of the catalyst. No. figure No. figure No. figure

Claims (2)

[Claims] (1) For a hydrogenation reaction that involves spraying a solution containing at least one type of metal element to serve as a carrier and one or more types of metal element to serve as an active species into a heated oxidizing atmosphere, and reducing the resulting oxide. Catalyst manufacturing method. (2) The manufacturing method according to claim (1), wherein the metal element to be the active species is nickel.