Preparation method of automobile exhaust purification catalyst

Abstract

The invention discloses a preparation method of an automobile exhaust purification catalyst, and relates to the technical field of automobile exhaust treatment. The preparation method of the automobile exhaust purification catalyst comprises the following steps: preparation of an oxygen storage material, pretreatment of a carrier, preparation of alumina powder slurry, preparation of an activated alumina layer and preparation of a final catalyst. In the carrier treatment process, malic acid and nitrate are used for treatment, a carrier is pretreated, 1, 4-butyrolactone is added in the preparation of activated aluminum oxide powder slurry, and an oxygen storage layer is prepared and formed in the carrier and in a catalyst coating. According to the preparation method of the automobile exhaustpurification catalyst, the specific surface area of the carrier is increased through acid etching, and the oxygen storage layer is prepared and formed in the carrier and the catalyst coating so thatthe positive-valence catalyst has the oxygen storage capacity, the phenomenon that the activated aluminum oxide layer falls off in the using process is reduced by adding 1, 4-butyrolactone into the activated aluminum oxide powder slurry, and the tail gas purification effect is obvious.

Description

technical field [0001] The invention belongs to the technical field of automobile exhaust gas treatment, in particular to a preparation method of an automobile exhaust gas purification catalyst. Background technique [0002] Exhaust gas emitted by locomotives is one of the main sources of air pollution. The main pollutants of medium and heavy diesel vehicles are nitrogen oxides, and their emissions are extremely harmful to the ecological environment and human health. Nitrogen oxides in combustion exhaust are usually produced by the reaction of nitrogen in fuel and nitrogen in air with oxygen at high temperatures. Taking internal combustion engines, especially diesel engines and other oxygen-rich combustion engines as examples, the exhaust gas contains pollutants such as carbon monoxide, hydrocarbons, carbon particles and nitrogen oxides. In the case of a gasoline engine, the oxygen in the air is mixed with the fuel in a stoichiometric ratio, and the pollutants are free of ...

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Problems solved by technology

[0003] The composition of the automobile exhaust catalyst commonly used in actual production is: coating a coating with a large specific surface area on the carrier, and then loading Pt, Rh, Pd and other noble metal catalytic active components, due to the small specific surface area of ​​the cordierite honeycomb ceramic carrier , the loaded active components are low, so that the exhaust gas purification effect is not obvious, and the catalytic converter is eroded by the high-temperature air flow for a long time during use, so that the active aluminum layer on the surface gradually falls off the carrier. Therefore, we propose a catalyst for automobile exhaust gas purification preparation method

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