JPH05103981A - Noble metal substrate for catalyst - Google Patents

Abstract

PURPOSE:To provide a noble metal substrate for a catalyst usable at >=1,000 deg.C, capable of enhancing adhesive strength to a carrier layer and capable of prolonging the service life of a catalyst for combustion of gaseous fuel. CONSTITUTION:Zr is allowed to enter into solid soln. in Pt, Pd or a Pt-Pd alloy and an oxide layer of ZrO2 is formed on the surface by heat treatment to obtain a noble metal substrate for a catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noble metal substrate for a fuel gas combustion catalyst for a gas turbine or the like.

[0002]

2. Description of the Related Art The use of a metal as a base material for a fuel gas combustion catalyst is effective because of its good thermal conductivity and processability into a honeycomb, and stainless steel is usually used. (As a prior art, there is JP-A-56-96762).

By the way, the base material of stainless steel is 1000 ° C.
If it becomes the above, the use of it will be restricted because the corrosion by oxidation will progress rapidly. In particular, it was far from reaching the minimum life of 8000 hours as a fuel gas combustion catalyst for gas turbines. Further, the weak adhesion to the carrier layer also shortened the life of the fuel gas combustion catalyst.

[0004]

Therefore, according to the present invention, 1000
An object of the present invention is to provide a noble metal substrate for a catalyst, which can be used at a temperature of not less than 0 ° C. and has a strong adhesive force with a carrier layer and which can prolong the life of a fuel gas combustion catalyst.

[0005]

A noble metal substrate for a catalyst according to the present invention for solving the above-mentioned problems includes Pt, Pd, and Pt-P.
Zr is solid-dissolved in any of the d alloys and heat-treated to form an oxide layer of ZrO _{2 on} the surface. The heat treatment is carried out at 500 to 1000 ° C. for 2 to 20 hours, preferably 900 ° C. for 16 hours.

[0006]

Since the noble metal substrate for a catalyst of the present invention constructed as described above contains Pt, Pd, or a Pt-Pd alloy as a main component, it is free from corrosion deterioration due to oxidation at 1000 ° C. or higher. It is extremely effective as a noble metal substrate for fuel gas combustion catalysts used at 1000 ° C or higher in gas turbines. Also P
Since Zr is solid-dissolved in any one of t, Pd, and Pt-Pd alloy and a ZrO ₂ oxide layer is formed on the surface by heat treatment, this oxide layer is formed of Pt, Pd, or Pt-Pd alloy. Tightly tied to either. Therefore, this Zr
O ZrO ₂ over the oxide layer ₂ has the same crystal structure as that of ZrO ₂ such as ZrO ₂ · SiO _2, high affinity, of the strong interaction high surface area ceramic catalyst support plasma spray, spraying Since it is firmly bonded and not peeled off by attaching it by a method such as painting, depping, etc., 1000
It is possible to extend the life of the fuel gas combustion catalyst used in a gas turbine or the like used at a temperature of not less than 0 ° C.

[0007]

EXAMPLE An example of the noble metal substrate for a catalyst of the present invention will be described. Pd containing 2%, 5% and 10% of Zr in solid solution was heat treated at 900 ° C. for 12 hours, and the cross section was obtained. After polishing, it was confirmed by SEM observation that a very dense and firm film was formed on the surface. When each film was inspected by an X-ray diffractometer, it was confirmed to be a ZrO ₂ layer.

As described above, Zr is solid-dissolved in Pd, and a ZrO ₂ layer is formed on the surface by heat treatment.
There is no deterioration of corrosion due to oxidation at 1000 ° C or higher, and it is effective as a base for fuel gas combustion catalysts. Moreover, since the surface ZrO ₂ layer is firmly bonded to Pd, ZrO ₂ layer is
When a catalyst carrier of high surface area ceramics with a similar crystal structure such as O ₂ and ZrO ₂ · SiO ₂ that has high affinity and strong interaction is attached by methods such as plasma spraying, spraying, coating, and depping, it becomes strong. It was bonded and never peeled off. Therefore, the noble metal substrate for the catalyst of this example has a temperature of 1000 ° C.
It is possible to extend the life of the fuel gas combustion catalyst used in the gas turbine or the like.

[0009]

Using the catalyst noble metal substrates As described above the present invention, since no peeling made strongly bonded catalyst support of high surface area ceramic ZrO _2, etc. ZrO ₂ · SiO _2, the present invention If the substrate of (1) is used as a substrate of a catalyst for burning fuel gas such as a gas turbine used at 1000 ° C. or higher, the life of the catalyst for burning fuel gas can be extended.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F23C 11/00 306 7815-3K

Claims (1)

[Claims] 1. A noble metal substrate for a catalyst, wherein Zr is solid-solved in any of Pt, Pd, and Pt-Pd alloy and a ZrO ₂ oxide layer is formed on the surface by heat treatment.