CN102389812A - Automobile exhaust catalyst containing Fe-Al-Cr alloy and preparation method of the same - Google Patents

Abstract

The invention discloses an automobile exhaust catalyst containing Fe-Al-Cr alloy and a preparation method of the same. The automobile exhaust catalyst is prepared by taking Fe-Al-Cr alloy as a carrier, adopting Ce-Zr-La composite oxide and gamma-Al2O3 as assistants and carrying active ingredient Pd. Without the action of other substances, the catalyst can invert NO, CO and HC with serious pollution on atmosphere in the automobile exhaust, and the catalyst is high in conversion rate, low in toxicity and high in catalytic activity.

Description

A kind of automobile-used tail-gas catalyst that contains the Fe-Al-Cr alloy and preparation method thereof

Technical field

The present invention relates to automobile-used tail-gas catalyst of a kind of Fe-Al-Cr of containing alloy and preparation method thereof, is that it is to polluter NO in the vehicle exhaust specifically _X, HC and CO carry out the catalyst and the synthetic technology thereof of integrated treatment.

Background technology

Automobile has become requisite part in our daily life.Automobile has also produced many bad accessory substances bringing us simultaneously easily.Tail gas pollution is exactly one of accessory substance, also is one of main source of atmosphere pollution simultaneously.Most NO in the city _X, CO, HC and CO ₂All make CO by vehicle exhaust ₂Cause the one of the main reasons of atmosphere pollution and greenhouse effects especially.NO _X, CO, HC not only cause damage but also produce blue photochemical fog under certain conditions human body, makes vegetation dead, the environment of human survival is destroyed.

At present, the major measure of control motor vehicle exhaust emission is to develop the purification techniques of auto-exhaust catalyst efficiently.Currently use maximum auto-exhaust catalysts to be noble metal triple effect catalyst (TWC), noble metal catalyst has higher activity, and big extremely ratio is occupied in tail-gas catalyst market in the world, but itself also has a lot of shortcomings.Have only when the scope of air-fuel ratio is controlled at (14.6 ± 0.3), just can make NO _X, CO and HC detergent power reach maximum, outside this scope, catalytic effect is all relatively poor.Noble metal catalyst was poisoned when elements such as Pb, S, P all were prone to, wherein Pb having the greatest impact to TWC.The price of noble metal is expensive, and the noble metal scarcity of resources also makes the application of TW C and popularization be restricted at present.

Summary of the invention

The objective of the invention is to the costing an arm and a leg of noble metal in the prior art, shortcoming such as toxicity is big provides the little activity of a kind of toxicity higher auto-exhaust catalyst.

Technical scheme of the present invention is: a kind of automobile-used tail-gas catalyst of the Fe-Al-Cr of containing alloy, this catalyst is a carrier with the Fe-Al-Cr alloy, Ce-Zr-La composite oxides and γ-Al ₂O ₃Be auxiliary agent, supported active composition Pd processes.Said component Ce-Zr-La composite oxides, γ-Al ₂O ₃, Pd is 1 ~ 3:2 ~ 6:1 ~ 3 at the load capacity proportion by weight of integer catalyzer.

The preparation method who contains the automobile-used tail-gas catalyst of Fe-Al-Cr alloy comprises the steps:

A is with Ce-Zr-La composite oxides and γ-Al ₂O ₃According to mass ratio is that the ratio of 1 ~ 3:2 ~ 6 adds the deionized water press amount of the mixture 20% ~ 50%, and in the adding ball grinder, ball milling 3 ~ 6h processes slurry;

B immerses Fe-Al-Cr alloy carrier in the slurry, takes out behind 1 ~ 5min, dries, and dries by the fire 3 ~ 6h at a certain temperature;

C is immersed in the PdCl that contains Pd1 ~ 3g/L with the carrier of oven dry ₂In the ammonia solution, stir 3 ~ 6h, take out, dry, dry by the fire 3 ~ 6h at a certain temperature;

D immerses KBH with the carrier of oven dry ₄In the solution, reaction 10 ~ 50min spends deionised water, at room temperature carries out chemical plating again, and reaction 10 ~ 50min is washed till neutrality with deionized water, at a certain temperature oven dry.

It is short that the present invention has overcome the conventional catalysts life-span, is prone to poison, and confirming of poor stability realized long-acting, stable high, safe.

The present invention has adopted the method for chemical plating, and it is simple that more traditional technology has an equipment, invest lowly, and chemical plating coating is even, and the hardness height resistance to wears, and is corrosion-resistant.

Description of drawings

Fig. 1 catalyst is to NO _X, CO and HC conversion ratio be with temperature changing curve diagram.

The specific embodiment

Instance 1 Ce-Zr-La composite oxides, γ-Al ₂O ₃Synthetic with the Pd/Fe-Al-Cr alloy:

With Ce-Zr-La composite oxides and γ-Al ₂O ₃According to mass ratio is the deionized water of the ratio adding of 2:3 by amount of the mixture 30%, adds in the ball grinder, and ball milling 5h processes slurry.Cordierite honeycomb ceramic carrier is immersed in the slurry, take out behind the 2min, dry, dry by the fire 4h down at 115 ℃.The carrier of oven dry is immersed in the PdCl that contains Pd2.2g/L ₂In the ammonia solution, stir 4h.Take out, dry, dry by the fire 4h at a certain temperature.The carrier of oven dry is immersed KBH ₄In the solution, reaction 30min spends deionised water, at room temperature carries out chemical plating again, and reaction 30min is washed till neutrality with deionized water, dries down at 115 ℃ and obtains Ce-Cr-La composite oxides, γ-Al ₂O ₃With the Pd/Fe-Al-Cr alloy.

Instance 2 catalyst are investigated the catalytic activity of vehicle exhaust:

With the prepared catalyst of instance 1 to the NO in the vehicle exhaust _X, CO and HC conversion ratio investigate.Test is in high temperature reaction stove, to carry out.To contain NO, CO ₂, H ₂Gaseous mixture feed in the high temperature reaction stove, every min heats up 10 ℃, finally rises to 500 ℃.Experimental result is seen table 1 and Fig. 1.

Table 1

Claims (3)

1. automobile-used tail-gas catalyst that contains the Fe-Al-Cr alloy is characterized in that it is is carrier with the Fe-Al-Cr alloy, Ce-Zr-La composite oxides and γ-Al ₂O ₃Be auxiliary agent, supported active composition Pd processes; Said component Ce-Zr-La composite oxides, γ-Al ₂O ₃, Pd is 1 ~ 3:2 ~ 6:1 ~ 3 at the load capacity proportion by weight of integer catalyzer.

2. the preparation method who contains the automobile-used tail-gas catalyst of Fe-Al-Cr alloy according to claim 1 is characterized in that comprising the steps:

A is with Ce-Zr-La composite oxides and γ-Al ₂O ₃According to mass ratio is that the ratio of 1 ~ 3:2 ~ 6 adds the deionized water press amount of the mixture 20% ~ 50%, and in the adding ball grinder, ball milling 3 ~ 6h processes slurry;

B immerses Fe-Al-Cr alloy carrier in the slurry, takes out behind 1 ~ 5min, dries, and dries by the fire 3 ~ 6h at a certain temperature;

C is immersed in the PdCl that contains Pd1 ~ 3g/L with the carrier of oven dry ₂In the ammonia solution, stir 3 ~ 6h, take out, dry, dry by the fire 3 ~ 6h at a certain temperature;

D immerses KBH with the carrier of oven dry ₄In the solution, reaction 10 ~ 50min spends deionised water, at room temperature carries out chemical plating again, and reaction 10 ~ 50min is washed till neutrality with deionized water, at a certain temperature oven dry.

3. the preparation method who contains the automobile-used tail-gas catalyst of Fe-Al-Cr alloy according to claim 2 is characterized in that: after the d step supported catalyst active ingredient is peeled off into powder or processed solution.