Prepn of three-effect automobile tail gas purifying catalyst on foamed ceramic carrier

Abstract

The present invention provides one kind of tail gas purifying three-effect catalyst with foamed ceramic carrier. Microwave absorbing carrier and gamma-Al2O3 powder are adhered together by using ethyl silicate so as to load catalyst onto the microwave absorbing carrier. The catalyst has chiral features, can absorb microwave energy effectively for homogeneous heating, has active coating prepared through new technological process, and may be used to purify automobile tail gas effectively under the action of microwave with excellent cold start effect.

Description

technical field [0001] The invention relates to a method for preparing a gas purification catalyst. Background technique [0002] With the development of world science and technology and economy, automobiles have become a symbol of modern civilized society and an inseparable part of modern society. However, while automobiles provide convenient transportation for human beings, they also emit waste gas that pollutes the environment and become one of the main sources of environmental pollution. The automobile exhaust emission standards have been formulated and promulgated successively, and the standards are becoming more and more stringent. Taking the European emission regulations as an example, the four standards that have been issued are more stringent than the other. The current regulations are the European No. No. 3 standard, in order to meet the requirements of the standard, in addition to adopting the internal control technology to reduce the generation of pollutants, th...

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Problems solved by technology

However, while automobiles provide convenient transportation for human beings, they also emit waste gas that pollutes the environment and become one of the main sources of environmental pollution. The automobile exhaust emission standards have been formulated and promulgated successively, and the standards are becoming more and more stringent. Taking the European emission regulations as an example, the four standards that have been issued are more stringent than the other. The current regulations are the European No. No. 3 standard, in order to meet the requirements of the standard, in addition to adopting the internal control technology to reduce the generation of pollutants, the installation of three-way catalyst is the main external purification method for exhaust gas purification. Due to the addition of precious metals and mature preparation technology, The existing three-way catalysts can basically meet the current emission regulations, but it seems a bit incapable to meet the upcoming Euro 3 and Euro 4 standards, because the core of Euro 3 and Euro 4 standards is to reduce the cooling Start-up pollution, that is, to reduce the pollutant emission during the period from the start of the car to the activation of the catalyst. Because the temperature of the catalyst is low during this period (2 to 3 minutes), it is difficult for the catalyst to effectively purify the exhaust gas. This problem does not depend on Simple addition of precious metals regardless of cost can solve the problem. Therefore, in order to meet future emission regulations, new purification technologies must be developed. Microwave heating has the advantages of rapidity, uniformity, and high selectivity. One of the keys to using microwave heating technology is: the catalyst must be Only with strong microwave absorption ability can the microwave energy be fully utilized. At present, the practical three-way catalysts all use cordierite honeycomb ceramics as the carrier, and the ability to absorb microwaves is very weak, so it cannot be used as a catalyst in microwave heating technology.