A kind of preparation method of catalyst for automobile exhaust gas and its product and application

Abstract

The invention discloses a preparation method of a catalyst for automobile tail gas as well as its product and application. By first loading a coating containing magnesium-modified alumina, samarium oxide and yttrium oxide-modified cerium-zirconium solid solution and aluminum sol on the cordierite honeycomb ceramic substrate, then loading the noble metal palladium, and then loading the coating containing magnesium-modified alumina , samarium oxide and yttrium oxide modified cerium zirconium solid solution and aluminum sol coating, and then load rhodium, coating by the above method can effectively avoid the alloying of palladium and rhodium, and magnesium modified alumina can effectively reduce the precious metal At the same time, the presence of magnesium can significantly improve the activity and sulfur resistance, and the oxygen storage and release performance and thermal stability of the catalyst can be improved by using samarium oxide and yttrium oxide to modify the cerium-zirconium solid solution, so the catalyst is used for Ideal material for automobile exhaust treatment.

Description

technical field [0001] The invention relates to the field of automobile tail gas treatment, in particular to a method for preparing a catalyst for automobile tail gas and its product and application. Background technique [0002] As we all know, the main pollutants of automobile exhaust are carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NO x ) three components. Moreover, the discharge of these toxic and harmful gases not only pollutes the environment, induces photochemical smog, causes secondary pollution, and even causes acid rain, greenhouse effect and ozone hole effect, even threatens human health, and even causes life danger. Therefore, how to reduce the pollution of the above substances Emissions are an important issue that needs to be solved urgently. [0003] Utilize catalytic technology to accelerate the redox reaction of CO, HC and NOx in automobile exhaust gas, and convert most pollutants into harmless CO 2 、H 2 O and N 2 , in order to achieve th...

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Problems solved by technology

Moreover, the discharge of these toxic and harmful gases not only pollutes the environment, induces photochemical smog, causes secondary pollution, and even causes acid rain, greenhouse effect and ozone hole effect, even threatens human health, and even causes life danger. Therefore, how to reduce the pollution of the above substances Emissions are an important issue that needs to be solved urgently

[0003] Utilize catalytic technology to accelerate the redox reaction of CO, HC and NOx in automobile exhaust gas, and convert most pollutants into harmless CO 2 、H 2 O and N 2 , in order to achieve the purpose of purifying automobile exhaust, due to the increasingly stringent emission standards, relying only on the current catalyst in the machine and unable to meet the needs of the current stage, how to provide an excellent catalyst that can efficiently remove the above substances is still a huge challenge

[0004] Platinum group metals (Pt, Rh, Pd) are the main active components of catalysts for automobile exhaust. Among the three noble metals, Pd catalysts have good activity for the oxidation of HC, and their high temperature resistance is also stronger, which is better than that of Pt and Rh. , but poor anti-poisoning ability, especially for SO 2 Sensitive to lead Pb poisoning

The noble metal rhodium Rh has a high reduction activity to nitrogen oxides NOx, but it is easy to form an alloy with Pd at high temperature, which greatly reduces its catalytic activity.

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