摘要
首先采用50%草酸溶液对蜂窝状堇青石进行沸煮处理,研究酸蚀处理对其组成和孔结构的影响.采用不同方法在其表面涂敷氧化铝涂层,考察酸蚀预处理对不同涂敷过程的影响.然后,对氧化铝涂层分别进行表征和比较.结果表明,(1)随着沸煮时间逐渐延长,蜂窝状堇青石腐蚀程度加剧,内部微孔增多,进而形成介孔,比表面积和平均孔径逐渐增大.(2)除硝酸盐热分解法外,采用传统浸渍法、原位涂敷+浸渍法和铝浆洗涂法涂敷时,将堇青石进行酸蚀预处理均不利于后续A l2O3涂层的涂敷.(3)采用传统浸渍法和铝浆洗涂法,酸蚀预处理都只是增大其涂层的比孔容积.而采用原位涂敷+浸渍法,预处理还会明显影响涂层的内部孔结构.其原因可能是预处理将影响A l2O3溶胶的原位形成过程,从而影响涂层的孔结构.
The cordierite honeycomb is treated in boiling 50% oxalic acid solution before A1203 is coated onto with various methods. The change of porous structure of the honeycomb resulting from different boiling time is studied. The influence of acid pretreatment on coating process and obtained Al2O3 coatings is investigated. The results shows that, （ 1 ） Along with extension of boiling time, the corrosion content of cordierite due to acid treatment is increased and micro-pores are gradually created, then micro-pores are formed, leading to the increase in specific surface area and average pore diameter; （2） When Al （NO3 ）3 thermal decomposition is applied, the coating process is improved, but opposite for the other coating methods, i.e. conventional dip-coating, in-situ dip plus-coating and Al2O3 slurry wash-coating; （3） As for in-situ dip plus-coating, acid pretreatment of cordierite not only increases pore volume of its Al2O3 coating but also exerts an significant influence on pore structure, probably due to intervention of the treatment into in-situ formation of Al2 O3 sol. However, only increase in pore volume of Al2O3 coating, which was deduced from the treatment is observed, when conventional dip-coating or Al2O3 slurry wash-coating method is employed.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2006年第6期550-555,共6页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金资助项目(20271012)
福建省科技计划项目(2002H026)
