堇青石陶瓷蜂窝载体的微观结构分析

采用XRD、SEM、EDS以及N2和汞吸附-脱附比表面积和孔径分布等分析手段,对机动车尾气净化催化剂陶瓷蜂窝载体的微观结构进行了研究。结果表明:虽然国内产品的化学组成和相组成与国外产品的基本相同,但其比表面积和孔结构等微观结构相差较大。这主要是由于国外采用全生料配料成型,在一次烧成中同时完成堇青石的合成和产品的烧成;而国内普遍采用合成的堇青石配料,经过挤出成型、干燥、切割后再烧成,致使堇青石原料中堇青石晶粒之间的孔被压塌陷,最终产品中的孔主要是堇青石二次颗粒之间的孔。据此认为,我国应努力研究堇青石的一次合成(烧成)工艺,这既能提高产品性能又能降低能源消耗。

Microstructure analysis of cordierite honeycomb ceramic carrier

Microstructures of cordierite honeycomb ceramic carrier for the automobile exhaust purification catalyst were investigated by XRD,SEM,EDS,N_2 and Hg adsorption-desorption specific surface area and pore size distribution methods.Although the homemade products have the same chemical composition and phase composition as the overseas products,their specific surface area and pore microstructure are rather different.The reason is that complete raw materials adopted in abroad products can realize the cordierite synthesis and product sintering simultaneously.However,the synthesized cordierite materials used in domestic products are sintered after molding,drying and cutting,which leads to the collapse of the original pores between cordierite grains.So the pores of the finished products are those between secondary grains of cordierite.Hence,one stage sintering technology should be developed in China in order to enhance the product performance and reduce the energy consumption.