JPS62149342A - Production of high dispersion type rhodium-containing catalyst - Google Patents

Abstract

PURPOSE:To effectively use costly rhodium by depositing a specific amt. of rhodium which is catalyst component onto a silica carrier having a specific surface area, pore volume and pore volume distribution of the specific pore size in specific ranges. CONSTITUTION:A silica carrier having 20-800m<2>/g specific surface area of a gaseous N2 method, 0.110-1.8cc/g pore volume of an Hg penetration method and >=0.110cc/g pore volume of 36-75Angstrom pore size is prepd. The catalyst component contg. rhodium is impregnated and deposited into and onto the silica carrier in such a manner that the rhodium is incorporated therein at <=60wt% to produce the high dispersion type rhodium-containing catalyst. An promoters such as Mn, Mg, Sc, and Ir are used as the promoter in combination in addition to the rhodium. The deposition of the catalyst components on the carrier may be executed either by the simultaneous deposition of all the catalyst components thereon or the subsequent deposition by each component on the carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a catalyst in which a component mainly containing rhodium is supported on 7 Lika.

Currently, in the chemical industry, attention is paid to the usefulness of heterogeneous fluxes supporting noble metals, and a wide range of research and development is being carried out on oxidation and reduction reactions of Mo, W, etc., centering on Group II metals. Unlike other inorganic porous supports such as alumina and titania, the warp support is an inert support and is known as a unique support that does not exhibit the 5M5I effect, and is widely used as a support that fully brings out the performance of precious metals. It is being No. 1 in the hydrogenation of olefins, hydrogenation of carbonyls, nuclear hydrogenation of aromatics, dehydration reactions, carbonylation as a step in the synthesis of oxygenated compounds under high pressure conditions, and also in the exhaust gas field.

It is also used for the oxidation and reduction of SOx and hydrocarbons, and occupies an important position as a catalyst.

It is expected that it will be an extremely effective catalyst for various hydrogenation reactions.

(Description of Prior Art) Among supported metal catalysts, there is a reaction in which a specific carrier is used and raw materials are added to reform the hydrogen ratio of hydrocarbons. (Recent patents include JP-A-60-112888, JP-A-60-105636, JP-A-60-54735, JP-A-60-27646, etc.) Catalysts using silica carriers include Pd as the main component. Oxidation catalyst (JP-A-6O-878
57). Furthermore, as a silica catalyst containing Rh as a main component, a catalyst for producing fuel gas (Japanese Patent Application Laid-Open No. 59-1128
40), a low-temperature fuel catalyst (Japanese Unexamined Patent Publication No. 58-14948) is disclosed. Furthermore, silica carriers are often used in gas phase reactions to synthesize oxygen-containing compounds from synthesis gas.

These aims are achieved by using very specific carriers that have a peak at a specific pore size.

In addition, as seen in JP-A-57-194044, high dispersion is achieved by thermal decomposition of acetylacetonate salt in an oxidized state, and JP-A-52-142689 is used to achieve high dispersion using a well water-based organic solvent. , the ingenuity in the preparation method can be seen.

Further, the metal alkoxide method is one of the methods for achieving high dispersion and is useful, but it requires a large number of steps and is far different from the simplicity of the present invention. The ion exchange method is also widely used as a highly dispersed catalyst preparation method, but it has many practical problems, such as contamination of raw material salts with ammine complexes and insufficient adsorption onto the silica carrier.

(Simplified explanation of the invention) Here, the present invention provides a silica catalyst containing rhodium as a main component, in which the silica support used has (1) a specific surface area of 20 m27f1 or more and 8
00 m2/jl or less, and (ii) Hg intrusion method (contact angle 1400, surface tension 4
The pore volume measured at 80 dynes/cm ) is 0.110 ccyJ or more, 1.8 cc/! It is in the range of 17 or less and G! Using a silica carrier with physical properties such that the pore volume of the side pore diameter of 36X to 75X is 0.110 cc/f1 or more, the rhodium to be impregnated is 6.
By supporting 0% by weight or less, it has become possible to achieve the objective by combining a body with the above physical properties with the simplest impregnation method.

(Description of the invention) First, as catalysts containing rhodium, catalysts to which co-catalysts other than rhodium are added are also effective, but in general Rh
6.0% by weight or less, and Rh can be used in metallic form or as a trivalent or less valent rhodium salt or complex.

As a promoter, Mn, Mg, Sc, Ir, Zr+Hf
+Mo, W, U, Th, etc., and alkali metals or alkaline earths, such as Na, K, Li
, Cs, Rb, Ca, St +13a
etc. may also be included. Lanthanides as rare earth elements,
Can any element in the actinide series be used? ! do.

Compounds used as promoters include inorganic acid salts such as halogenates, sulfates, nitrates, and carbonates.

Any organic acid salt such as oxide, hydroxide, acetate, formate, oxalate, etc. can be used. However, in order to facilitate the support of these catalyst components on the carrier, compounds soluble in water or other suitable catalysts (with a specific surface area measured using N2 gas of 20 m2/!1 or more, 800 m2/!
Hg intrusion method (contact angle 140', surface tension 480 dyne s/l)
yn ) is 0.110 cc/,
') or more and 1.8 cc/'l or less, and (iii) the pore volume of 1 pore diameter of 36X to 75X is 0.
Using a silica carrier having physical properties of 110 cc/g or more, it is possible to obtain a supported and fixed target object by adding MJ solubilizer and supporting it by a conventional method of impregnation, and then reducing or heat treating it. can. Especially by drying at low temperature,
Furthermore, by sufficiently removing the impregnating solvent, it becomes possible to form rhodium particles with a better diameter.

The catalyst components may be supported on the carrier at the same time, or each component may be supported on the carrier sequentially, or each component may be subjected to reduction, heat treatment, etc. as necessary. is activated to a substantially metallic state and then subjected to reaction. The reduction treatment can be carried out under hydrogen gas or under a mixed gas of hydrogen and carbon oxide, or in some cases under hydrogen gas partially diluted with an inert gas such as nitrogen, helium, or argon, or under the above mixed gas. can.

The reduction treatment temperature is 100 to 600°C, preferably 2
It is carried out at a temperature of 50-550°C. At this time, in order to maintain the activation state of each component of the catalyst in an optimal state, the reduction treatment may be performed while raising the temperature gradually or stepwise from a low temperature.

Also, rhodium compounds can be reduced using methanol, hydrazine,
This may be carried out by treatment with a reducing agent such as formalin.

Hereinafter, the present invention will be explained in more detail with reference to examples, but these examples intentionally unify the conditions in order to facilitate understanding of the present invention, and the present invention is not limited in any way by these examples. Of course not.

Example 1 Specific surface area 196 m2/jl, average pore diameter (4v/jl)
s) The pore distribution of the silica carrier rA-IJ having the above physical properties is shown in Figure 1, and Table 1 shows the physical properties and the ratio of Rh to adsorbed carbon monoxide (dispersion rate). XRD (Cu-Kd)
Rh particles were measured, but were not detected.

The catalyst preparation method is shown below.

23.4 g (50 ml) of the above silica carrier was mixed with 2.551 g of rhodium chloride hydrate (RhC1,.3H20),
Iridium chloride (IrCl4-H2O) 0.427
,! 7 Manganese chloride (MnCl2・4H20) 0.0
40 F, lithium chloride (Lict) 0.0269 was added to 16 ml of an aqueous solution uniformly dissolved, and uniformly impregnated.
It was air-dried at room temperature for 2 hours. 4 hours at 30℃, 2 hours at 60℃
Dry under reduced pressure in a rotary evaporator for 450 hours.
Hydrogen reduction was performed at ℃ for 2 hours.

Example 2 Silica-supported Kr having various physical properties as shown in A-2 of Table 1
The same preparation as in Example 1 was carried out using A-2J. The carrier used was 22.3.9 (50ml), and the aqueous solution was 19.
m(! Closed. Figure 2 and Table 1 show the physical properties of the silica carrier and
Show the dispersion rate of Rh.

The procedure was the same as in Example 1 except that the stock solution was 23.0 ml.

Comparative Example 2 As shown in Table 1 and Figure 4, silica (8 volatile chemical E56C1
Silica) was used. Carrier 25.9,! i'(50ml
) The procedure was the same as in Example 1 except that the aqueous solution was 17.0 ml.

[Brief explanation of drawings]

FIGS. 1 and 2 show the pore distribution of the carrier of the present invention (Example 1.2), and FIGS. 3 and 4 show the pore distribution of the carrier of soft ratio Example 1.2. The vertical axis of the drawing is the pore spy (integral value cc/
'l A-U-), the horizontal axis represents the pore diameter (A, U,).

Claims (1)

[Claims] (i) The specific surface area measured using N_2 gas is 20 m
The range is ^2/g or more and 800m^2/g or less, and (ii) Hg intrusion method (contact angle 140°, surface tension 480
Pore volume measured in dynes/cm) is 0.110c
c/g or more and 1.8 cc/g or less, and (iii) the pore volume with a pore diameter of 36 Å to 75 Å is 0.
A method for producing a rhodium-containing catalyst, which comprises impregnating and supporting a rhodium-containing catalyst component on a silica carrier having physical properties of 110 cc/g or more so that the rhodium content is 6.0% by weight or less.