JPS61234948A - Catalyst body - Google Patents

Abstract

PURPOSE:To blacken preliminarily a carrier itself by kneading previously the fine powder of a black transition metallic oxide with the powder of ceramic raw material, thereafter calcining the mixture to obtain a honeycomb type and furthermore depositing the black perovskite powder thereon. CONSTITUTION:In relation to a catalyst for purifying an exhaust gas which is provided to the inside of a combustion apparatus, the fine powder of a black transition metallic oxide is previously kneaded with the powder of a ceramic raw material being the raw material of a honeycomb structural body. After calcining the mixture to obtain a honeycomb type, a carrier 1 is immersed in a slurry-like liquid wherein the fine particles 5 of a perovskite composite oxide having the oxidation activity, colloidal alumina and a deposition aid such as Al(NO3)3 are mixed with water, dried and calcined. By such a way, even when the perovskite fine powder of the surface is separated, it is not unsightly in a fine view because the structure has the same color and the catalyst capacity is largely increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to carbonized 7X, which is the cause of incomplete combustion components and unburned components generated during combustion, and odors generated during various cooking processes.
This invention relates to an exhaust gas purification catalyst installed in combustion equipment to remove elemental components.

BACKGROUND OF THE INVENTION Various types of catalysts of this type have existed in the past. Specifically, the most common catalyst supporting platinum group metals is a porous ceramic carrier impregnated with an aqueous solution containing a platinum group metal, such as an aqueous solution of chloroplatinic acid, and then dried.
It is baked and attached to the surface of the pores of the carrier as fine metal particles or fine metal oxide particles. Although platinum group catalysts have good activity, their disadvantage is that they are very expensive. It is known that transition metal oxides or perovskite composite oxides incorporating a portion of transition metals have an activity comparable to that of platinum if the particle size is made very small. However, some complex oxides with a perovskite structure have considerably low activity and are also heat resistant. Therefore, if fine powder of these perogeskite compounds is adhered to a carrier, it becomes an excellent catalyst, but the adhered fine powder is inevitably weak in strength and tends to partially fall off. Only a small portion of the perovskite compound falls off, which has little effect on activity deterioration, but after the perovskite compound, which is mostly black, falls off, the white carrier surface becomes exposed, which is aesthetically undesirable. In particular, it is necessary to solve this problem for household combustion equipment.

Problems to be Solved by the Invention As described above, conventional carriers are almost white or nearly white in color, and when the attached black powder falls off, it becomes noticeable. The present invention has been made in view of this point, and an object of the present invention is to make the carrier itself black or a color close to black in advance.

Means for Solving the Problems The present invention solves the above problems by adding a black transition metal oxide to powders of various ceramic raw materials, which are the raw materials for the honeycomb structure, at the stage of creating a catalyst carrier for the honeycomb structure. The fine powder is kneaded in advance and fired into a honeycomb mold. The resulting catalyst carrier is black in color, and the catalyst body is made by supporting the perovskite black powder on the soil of the catalyst carrier.

Function The present invention has the above-described structure, and even if some of the supported catalyst powder is missing, no abnormality is observed in appearance. In addition, by mixing transition metal oxides into the catalyst carrier,
The catalytic oxidation capacity can be greatly increased compared to a catalyst carrier that is not mixed.

Embodiment FIG. 1 is a model diagram showing an embodiment of the catalyst body of the present invention. In FIG. 1, 1 is a catalyst carrier, 2 is a micropore existing in the catalyst carrier 1, and 3 is a transition metal oxide 4 mixed inside the catalyst carrier 1. A perovskite composite oxide 5 is firmly adhered to the outer surface 4 of the catalyst carrier 1 with alumina 6 produced by firing a supporting agent. As the supporting agent, a material such as colloidal alumina or aluminum nitrate, which becomes porous and has strong adhesive properties by firing, is used.

In the above structure, even if a part of the film of perovskite composite oxide 5 and alumina 6 attached to the surface of the catalyst body is missing due to some mechanical impact or contact, the underlying surface will remain black. Arudame's appearance never changes at all.

An example of the method for producing this catalyst will be described below.

The catalyst carrier is made of cordierite (2Mg0
・58i02 ・2A6203) powder and each fine powder of manganese dioxide (Mn02), tricobalt tetroxide (Co304), and triiron tetroxide (F e 304 ) at a ratio of 100:1.
: They were mixed at a ratio of 1:2, and in order to further increase the porosity, some organic matter was added, formed into a honeycomb shape, and fired, which was used as a catalyst carrier. On the other hand, fine particles of berovskite composite oxide (La□, g Co□, I Co03),
Aluminum nitrate (A4(N03)3.9H2o) 2
: Mix at a ratio of 1:1 and add water to make a slurry.

Furthermore, to make the slurry more stable, CMC1PV
The above-mentioned honeycomb-shaped catalyst carrier is immersed in the mixture, which has been adjusted to a predetermined viscosity by adding a small amount of A. Take out the soaked catalyst carrier, blow off the slurry liquid remaining in the 7p with wind pressure, and
After drying at 00'C for about 1 hour, drying at 800℃ for 5ml
~10 ml of firing is performed.

FIG. 2 is an example of the application of the catalyst of the present invention, in which the catalyst is mounted in a gas cooker.

A catalyst body 7 having a honeycomb shape is installed at an exhaust gas outlet 9 above an interior 8 of the cooking appliance. A wire mesh heating element 10 is placed on the top surface of the cooking chamber interior 8, and is heated to red heat by a gas burner 11.

Further, at the lower part of the interior 8 of the cooker, a stand 13 for placing food 12 to be cooked, a tray 14 for receiving oil from the food 12, etc. are installed.

In the above cooking device, the food 12 is placed on the table 12, the gas burner 11 is ignited, the wire mesh heating element 10 is made red hot, and the food 12 is cooked by the radiation and hot exhaust gas generated. At this time, odor-containing hydrocarbons generated from the food being cooked pass through the catalyst body 9 installed at the exhaust gas outlet 9 together with the exhaust gas generated from the gas bath 11, and the hydrocarbons are purified.

Effects of the invention (1) Since it is a catalyst in the form of a deposit of fine powder, even if the fine perovskite powder supported on the surface is detached, the background remains the same color, so it is not aesthetically unsightly, making it particularly suitable for household combustion. Ideal for use inside a vessel.

(2) Since the catalyst body of the present invention blackens by mixing transition metal oxide fine particles into the catalyst carrier, it is possible to greatly increase the catalytic performance compared to a catalyst body using a catalyst carrier that does not blacken. can.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a catalyst body according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the same catalyst body used in a cooking appliance. 1... Catalyst carrier, 2... Micropore, 3
...Transition metal oxide fine particles, 6...Perovskite composite oxide, 6...Alumina. Name of agent: Patent attorney Toshio Nakao and one other person
Hep17 Meshi 6ite! Figure 2/ψ 13

Claims (2)

[Claims] (1) A honeycomb structure made of a heat-resistant ceramic material with a deep color such as black, gray, or dark brown that has micropores inside is used as a catalyst carrier, and this catalyst carrier is used as fine particles of perovskite composite oxide having oxidizing activity. , and a catalyst body obtained by soaking a supporting agent such as colloidal alumina or aluminum nitrate, which becomes porous and has strong adhesive properties upon firing, in a slurry liquid mixed with water, drying, and firing. (2) Honeycomb structures made of colored heat-resistant ceramic materials are made of raw material powders such as cordierite, gamma and alpha alumina, mullite, zirconia, mullite-zircon, aluminum titanate, and petalite, and oxides such as manganese, cobalt, and iron. The catalyst body according to claim 1, wherein an oxide having a black color or a color close to black is mixed and fired in a honeycomb shape.