Motor vehicle exhaust catalytic converter, and its preparing method

Abstract

The invention discloses a motor vehicle exhaust catalytic converter, where the catalyst carrier is a metal cellular carrier using hot dip aluminized thin steel plate as precursor and made by micro-arc oxidized ceramic film process; the carried catalyst coating is a noble metal-rare earth combined catalyst coating formed on the carrier by making YSZ and Pd into mixed pulp and coating it on the carrier. And the invention also discloses a method for preparing the motor vehicle exhaust catalytic converter, making hot dip plating aluminum by salt bath process and in situ growing the ceramic film on the surface of the hot dip aluminized thin steel plate by micro-arc oxidizing process, where the ceramic film has a structure of crystalline oxide ceramic phase, compact and even, firm to bond, and having low making energy consumption, and outstanding advantages of improving purifying effect and prolonging the service life. And it is applied to exhaust purification for various motor vehicles using leadless gasoline.

Description

technical field [0001] The invention relates to catalytic conversion treatment of harmful components of internal combustion engine exhaust to make them non-toxic or other exhaust devices, in particular to a motor vehicle exhaust catalytic converter and its preparation method. Background technique [0002] Extensive use of motor vehicles has caused more and more pollution to the atmosphere. At present, the exhaust gas purification of motor vehicles mainly adopts two methods: internal purification and external purification. The external purification is mainly composed of a leading fluid, a carrier shell, a rear guiding fluid, and a honeycomb ceramic carrier that is placed in the carrier shell and is formed by winding a flat substrate and a wave-shaped wave carrier in the exhaust system. Exhaust catalytic converters are used to solve the problem of exhaust gas purification. A motor vehicle exhaust catalytic converter is a device installed in the exhaust system of a motor vehic...

AI Technical Summary

Problems solved by technology

However, the high-temperature oxidation process is to form an alumina whisker transition layer on the surface of FeCrAl metal, which is only suitable for metal supports rich in aluminum. This process cannot be used for ordinary metal supports, and its industrial application is limited; after surface phosphating process Phosphorus on the surface of the metal carrier can easily lead to phosphorus poisoning of the catalyst, forming a glassy compound on the surface of the catalyst, causing the loss of active points, reducing the catalytic activity, causing the catalytic converter to lose part or all of its functions too quickly, and significantly reducing the service life of the catalytic converter. The phosphating process will also cause pollution to the environment and is not suitable for use as a surface treatment process for metal carriers; as for the plasma spraying process on the wire mesh carrier, it will cause waste of materials, and the coating cannot be sprayed in depth and cannot handle metals with complex shapes. Honeycomb carrier; arc spraying also has the problem of material waste, which is not suitable for preparing porous substrate coatings, and it consumes a lot of energy and costs relatively high, which affects the wide use of catalytic converters to a certain extent

Images