Preparation method of NOx adsorbing material with HC catalytic oxidation function

Abstract

The invention discloses a preparation method of a NOx adsorbing material with an HC catalytic oxidation function. The method comprises the following steps of S1, molecular sieve pretreatment; S2, loading with precious metal; S3, roasting; S4, hydrothermal aging. The provided preparation method of the NOx adsorbing material with the HC catalytic oxidation function has the advantages that the obtained NOx adsorbing material has the functions of efficiently adsorbing and storing NOx at a low temperature and thermally desorbing the NOx at a high temperature, and also has a certain function catalytic oxidation function on the hydrocarbons.

Description

technical field [0001] The invention relates to the technical field of adsorption materials, in particular to a preparation method of a NOx adsorption material with HC catalytic oxidation function. Background technique [0002] As emissions regulations become more stringent, fuel efficiency increases, and engine exhaust temperatures decrease, engine cold-start emissions will become more difficult. [0003] During the implementation of China V emission standards for motor vehicles, SCR catalysts are usually used to reduce NOx to N 2 To achieve up-to-standard emission of motor vehicle exhaust. However, the upcoming National VI emission standards have greatly reduced the NOx emission concentration. The traditional SCR catalytic reduction of NOx has a high temperature requirement, which can no longer meet the NOx emission treatment during the cold start stage of the engine, resulting in excessive NOx emission during the cold start stage of motor vehicles. [0004] Existing tec...

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Problems solved by technology

However, the upcoming National VI emission standards will greatly reduce the NOx emission concentration. The traditional SCR catalytic reduction of NOx has a high temperature requirement, which can no longer meet the NOx emission treatment during the engine cold start stage, resulting in excessive NOx emission during the cold start stage of motor vehicles.

[0004] Existing technologies for treating NOx in exhaust exhaust from motor vehicles are no longer suitable for the National VI standards, because the temperature requirements for SCR catalytic reduction of NOx (generally not lower than 200°C) cannot be met during the cold start stage of the motor vehicle engine, so the SCR catalyst is lower than 200°C. At ℃, it does not have a catalytic reduction effect on NOx, so it cannot meet the emission reduction requirements of the National VI standard for nitrogen oxides (NOx).

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