以纳米多晶β沸石为壳的核壳Y型沸石复合物的制备及表征  

Synthesis and Characterization of Y-Type Zeolite Cores and a Nano-β Zeolite Polycrystalline Shell Composites

作　　者：潘梦[1] 王广帅[1] 郑家军[1] 鲍杰华 李彪[1] 李瑞丰[1] 

机构地区：[1]太原理工大学能源化工与催化研究中心,太原030024

出　　处：《硅酸盐学报》2015年第5期685-691,共7页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金委-中石化联合基金(重点支持项目:U1463209);国家自然科学基金(21371129;21376157;51272169)资助

摘　　要：将经过四乙基溴化铵交换后的Y型沸石加入到已预晶化23~117 h的β沸石反应混合物中,经二次水热晶化,将组成及合成条件差异巨大的Y型沸石和β沸石成功复合在一起,并得到了以Y型沸石为核、以纳米多晶β沸石为壳的核壳沸石复合物(Y@Nano-β)。研究了Y型沸石的四乙基铵根离子(TEA+)改性、改性Y沸石(TEA-Y)添加量、预晶化时间以及二次水热晶化时间等对Y@Nano-β沸石复合物形成的影响,探讨了Y@Nano-β核@壳沸石复合物的形成和生长机理。结果表明,制备条件对Y@Nano-β沸石复合物的形成影响较大。在β沸石合成体系中,Na Y远不及TEA-Y稳定,为得到核壳沸石复合物Y@Nano-β,需要将Na Y沸石交换成TEA-Y。控制每18 m Lβ沸石合成凝胶中加入1 g TEA-Y,β沸石的预晶化时间为96 h,第二步晶化时间大于75 h可以制备出以Y型沸石为核,以晶粒尺寸分布在50~100 nm之间的纳米多晶β沸石为壳的复合物。A zeolite-zeolite composite composed of Y zeolite cores and a nano-β zeolite polycrystalline shells(i.e., Y@Nano-β) with different zeolite structures and incompatible framework compositions was synthesized. The factors affecting the formation of the zeolite-zeolite composite of Y@Nano-β, such as Na Y with and without the modification by tetraethylammonium cation(TEA+), the amount of TEA-Y, the pre-treated time of precursor mixture for yielding β zeolite and the second-crystallization time were investigated. The formation mechanism of the as-synthesized zeolite-zeolite composite of Y@Nano-β was discussed. The results show that the preparation conditions play an important role in the formation of the zeolite-zeolite composite of Y@Nano-β. In order to obtain Y@Nano-β, it is necessary to modify Na Y by TEA+ because TEA-Y is more stable than Na Y in basic medium of β zeolite. The zeolite–zeolite composite composed of Y zeolite cores and polycrystalline β zeolite shells can be obtained at the amount of TEA-Y of 1 g(per 18 m L β gel), the pre-treated time of 96 h and the second-crystallization time of more than 75 h.

关 键 词：核壳结构 沸石复合物 纳米多晶β沸石 附晶生长 

分 类 号：TQ426[化学工程]