Catalytic complex for denitration of lean burn gasoline engine exhaust and preparation method thereof

Abstract

A catalytic complex for denitration of lean burn gasoline engine exhaust and a preparation method thereof aim to overcome unsuitability of an existing ternary composite catalyst catalytic complex for lean burn technology. The catalytic complex comprises a cellular titanium dioxide carrier and metal platinum, rare earth metal, and metal copper that are attached to the carrier. The preparation method includes steps of: immersing titanium dioxide into a copper sulfate pentahydrate solution with a concentration of 75%, and drying and roasting to obtain a copper / titanium dioxide catalyst complex; immersing the copper / titanium dioxide catalyst complex in a rare earth cerium solution, and then drying and roasting to obtain a cerium / copper / titanium dioxide catalyst complex; and immersing the cerium / copper / titanium dioxide catalyst into a platinum nitrate salt solution, and drying and roasting to obtain a nitrate platinum / cerium / copper / titanium dioxide catalyst complex. The invention is beneficial to nitrogen oxides and reduction thereof, and significantly reduces temperature of harmless transformation of nitrogen oxides, and improves the ability of resistance to sulfur poisoning of the catalyst. Besides, the catalytic complex reduces use amount of noble metal platinum and cost of catalyst, and conducts efficient reduction on NOx in lean burn of gasoline engine exhaust.

Description

Technical field: [0001] The invention belongs to the field of vehicles, in particular to automobile exhaust purifiers Background technique: [0002] Due to the further increase of human dependence on cars, the number of cars has exploded. Nitrogen oxides in automobile engine exhaust will be emitted into the atmosphere in large quantities, and nitrogen oxides (NO x ) is the main pollutant in the atmosphere. Nitrogen oxides will not only cause damage to the human respiratory system, but also the chief culprit of photochemical smog pollution, urban haze weather, and atmospheric acid deposition. For gasoline engines, in order to reduce exhaust emission standards, three-way composite catalytic converters are basically installed. The previous three-way composite catalytic converter can purify CO, HC compounds and NO better under the working condition of theoretical air-fuel ratio (14.7) x , but with the development of engine lean-burn technologies such as stratified combustion ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a lean-burn gasoline engine tail gas denitrification catalyst complex and its preparation method to overcome the fact that the existing three-way composite catalyst catalytic complex is not suitable for lean-burn technology, which leads to difficulty in adding reducing agents and easy to cause secondary pollution Problems and the use of (Pt / Rh / Pd) and other precious metals are not expensive, poor sulfur resistance and other shortcomings

Images