Three-way catalyst for treatment of tail gas of automobile and preparation method thereof

Abstract

The invention relates to a three-way catalyst for treatment of tail gas of an automobile. The three-way catalyst is prepared from the following components of an oxygen storage material, modified gamma-Al2O3 (aluminum oxide), a rare earth additive, an adhesive, and noble metal nitrate, wherein the modified gamma-Al2O3 is La (lanthanum)-modified gamma-Al2O3; the oxygen storage material is cerium-zirconium composite oxide; the weight ratio of oxygen storage material to modified gamma-Al2O3 is 2:3 to 3:2; the rare earth additive comprises one or multiple of nitrates of zirconium, praseodymium, neodymium and yttrium, and the amount of rare earth additive is equal to 1 to 5% of the total weight of the coating. The three-way catalyst has the advantages that in the coating preparation process, thenoble metal salt solution is firstly thinned, then added, and stirred, and stays overnight, so as to effectively inhibit the agglomeration of noble metals, improve the dispersion degree of noble metals, and improve the utilization rate of the noble metals; the low-temperature drying is adopted, so as to avoid the agglomeration of active components due to transfer of active components in the quickdrying process, and avoid the sintering in the roasting process; the usage amount of noble metals is reduced.

Description

Technical field [0001] The invention relates to automobile tail gas treatment, in particular to a three-way catalyst for automobile tail gas treatment and a preparation method thereof. Background technique [0002] In recent years, the number of cars in my country has gradually increased, bringing convenience to mankind, and the large amount of car exhaust emissions have also brought pollution that cannot be ignored. After the car is started, due to incomplete fuel combustion or high temperature, a large amount of CO, HC and NOx will be produced. These pollutants seriously harm the ecological environment and human health. Therefore, it is necessary to urgently solve the problem of automobile exhaust pollution. [0003] At present, the most effective way to deal with automobile exhaust is to install automobile exhaust purifiers. The key technology is the preparation of three-way catalysts. Three-way catalysts usually use ceramic honeycomb as the substrate, coated with activated al...

AI Technical Summary

Problems solved by technology

Three-way catalysts usually use ceramic honeycomb as the substrate, coated with activated alumina as the carrier, and then support noble metals Pt, Pd, Rh, etc. as active components to prepare a monolithic catalyst. The catalyst has two functions of catalytic oxidation and catalytic reduction, although It can effectively reduce the emission of HC, CO and NOx, but the preparation process of the catalyst is complicated and the cost of precious metals is high

The traditional preparation process, as described in patents CN200510062095.0, CN201510207711.0 and CN201310358641.X, adopts the coating method of direct immersion, and both the carrier and the active component need to be impregnated, dried and roasted multiple times to obtain the catalyst, not only The preparation process is complicated, the active components are easy to lose, the coating is easy to fall off, and after repeated drying and roasting, the precious metal is easy to sinter, and the utilization rate is low

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