摘要
以N-甲基二环己基胺(MCHA)为结构导向剂、正硅酸乙酯(TEOS)为硅源、氢氧化铝为铝源、85%的磷酸为磷源,采用水热法制备了不同硅含量的多级孔SAPO-5分子筛。采用X-射线粉末衍射(XRD)、氮气物理吸附、傅立叶变换红外光谱(FTIR)和氨程序升温脱附(NH3-TPD)等方法分别对样品的晶体结构、比表面积、骨架结构和酸性等进行表征。结果表明:随着硅含量的增加,多级孔SAPO-5分子筛的结晶度降低;孔径无明显变化,孔容增大;当硅含量为0.33时,样品不再具有AFI结构;总酸量随着硅含量的增加先升高后降低,当硅含量为0.20时,总酸量最大。
A series of hierarchical SAPO-5 molecular sieves with different silicon contents were prepared by hydrothermal synthesis using N,N-dicyclohexylmethylamine as structure directing agent,tetraethoxysilane （TEOS）as silica source,hydrated aluminum hydroxide as alumina source,phosphoric acid （85%）as phosphor-us source.The crystal structure,specific surface area,skeleton structure and acidity of SAPO-5 molecular sieves were characterized by XRD,N2-physical adsorption,FTIR and NH3-TPD,respectively.Results showed that, with the increase of silicon content,the crystallinity of hierarchical SAPO-5 molecular sieves was decreased;there was no significant alteration of the pore diameter with the silicon content increased,but the pore volume was increased;when the silicon content was 0.33,the sample was not AFI structure;the total acid amount in-creased at first and then decreased,the total acid amount reached the top value when the silicon content was 0.20.
出处
《化学与生物工程》
CAS
2014年第10期39-42,共4页
Chemistry & Bioengineering
基金
山西省青年基金资助项目(011281901031)
关键词
多级孔分子筛
SAPO-5
硅含量
表征
hierarchical molecular sieves
SAPO-5
silicon content
characterization
