Preparation method of composite oxide catalyst used for purifying diesel engine

Abstract

The invention relates to a preparation method of a composite oxide catalyst used for purifying a diesel engine and belongs to the technical field of catalysis. The catalyst is prepared with cordierite honeycomb-like ceramic as a carrier, with [gamma]-Al2O3 as a coating and with Pt as an active component with addition of components such as Ce, Ba and the like. In the composite oxide catalyst, one or two coated catalysts can be employed, when one coated catalyst is employed, the coated catalyst is one of an oxidizing catalyst or a reducing catalyst and the catalyst can be used for coating an A zone and a B zone of the carrier at different coating amounts; and when two coated catalysts are employed, one is the oxidizing catalyst and the other is the reducing catalyst. The one or two catalysts coat the same carrier with different loading capacities in the A zone and the B zone of the carrier. The composite oxide catalyst can effectively reduce discharge of PM and NOx in tail gas of the diesel engine, can effectively increase the conversion rates of the PM and the NOx, and is better in economy.

Description

technical field [0001] The patent of the present invention relates to a composite oxide catalyst for diesel engines and its preparation method, by providing different coating amounts of catalysts or coating different types of catalysts on the same catalyst carrier A area and B area; when the type of catalyst coated When it is one type, catalysts with different coating amounts are provided in the carrier A area and B area, which improves the overall utilization rate of the catalyst; when there are two types of catalysts coated, one is an oxidation catalyst, and the other is a Reduction catalyst, through oxidation and reduction catalysts, PM and NO in diesel engine exhaust can be reduced at the same time x emissions, and has a high economy. technical background [0002] Due to the advantages of high thermal efficiency, long service life and good reliability, diesel engines are widely used in construction machinery, automobiles and other fields; however, the PM and NO of diese...

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Problems solved by technology

[0002] Due to the advantages of high thermal efficiency, long service life and good reliability, diesel engines are widely used in construction machinery, automobiles and other fields; however, the PM and NO of diesel engines x The emission is relatively high, and it poses a great threat to the environment and human health. Among them, NO x It is easy to combine with water vapor and dust in the air to form photochemical smog and acid rain, and even smog, which will cause harm to the atmospheric environment and human health. PM contains polycyclic aromatic hydrocarbons with strong biological toxicity, such as benzopyrene, which is harmful to the heart. , Respiratory system is very harmful; pollutants in diesel engine exhaust mainly contain PM and NO x , NO x Mainly including NO and NO 2 ;

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