Porous conductive MAX phase ceramics and preparation method and use thereof

Abstract

The invention relates to a porous conductive ceramics, in particular to a porous conductive MAX phase (Ti3SiC2, Ti3AlC2 or Ti2AlC) ceramics with a through hole structure, and a preparation method and a use thereof. The porosity of the porous ceramics is adjustable within the range of 20-65%, the ceramics comprises a through hole structure, and the openporosity is more than 85%. The preparation method comprises the steps of taking MAX phase ceramic powder as a raw material, molding, carrying out pressureless sintering in an atmosphere furnace, keeping the sintering temperature at 1200-1400 DEGC, and leading the sintering time to be 0.5-3 hours. The MAX phase conductive ceramics with the through hole structure prepared by the pressureless sintering method can be used as a catalyst carrier material for automobile exhaust purification. The invention can solve the problems of liquid phase, a large number of closed pores in the generated hole and the like during the sintering process by optimizing the molding pressure, the sintering temperature and the time precise control of the porosity.

Description

technical field [0001] The present invention relates to porous conductive ceramics, specifically a porous conductive MAX phase (Ti 3 SiC 2 、Ti 3 AlC 2 or Ti 2 AlC) ceramics and its preparation method and use. Background technique [0002] Today, the number of automobiles is increasing rapidly, resulting in an increasing amount of automobile exhaust emissions. Carbon monoxide (CO), hydrocarbons (C x h y ), oxygen and nitrogen compounds (NO x ), sulfur dioxide, solid particles and aldehydes have a strong pungent taste or carcinogenic effect, and have become important sources of air pollution. [0003] In order to reduce the pollution of exhaust gas, internal purification measures such as exhaust gas recirculation and delayed ignition time and external measures such as high-efficiency catalytic technology are mainly adopted. High-efficiency catalytic technology converts CO, C x h y , NO x converted to CO 2 、H 2 O, N 2 . The three-way catalytic converter used is ...

AI Technical Summary

Problems solved by technology

Although the performance of the metal foil carrier is excellent, the molding process is complicated, especially the poor adhesion between the carrier and the catalyst active layer

[0004] At present, the main problems faced by the catalyst carrier in use are: the traditional ceramic carrier is non-conductive or has poor conductivity, is not easy to be electrically heated, and has poor thermal shock resistance; the metal foil carrier has good conductivity and can be electrically heated, but it is not compatible with the active layer Large difference in thermal expansion coefficient, the active layer is easy to peel off from the carrier

Due to the formation of liquid phase during the sintering process, the generated pores have a large number of closed pores. If it is used as a catalyst carrier material, it will reduce the effective use area of ​​the catalyst active layer on the carrier pore wall.

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