高稳定性介孔CaO-ZrO2固体碱的结构及碱性研究  

Structure and Basicity of Highly Stable Mesoporous CaO-ZrO_2 Solid Base

作　　者：刘水刚[1] 张学兰[1] 李军平[1] 赵宁[1] 魏伟[1] 孙予罕[1] 

机构地区：[1]中国科学院山西煤炭化学研究所

出　　处：《石油化工》2008年第3期226-231,共6页Petrochemical Technology

摘　　要：采用溶胶-凝胶法制备了具有介孔孔道的新型纳米CaO-ZrO2固体碱。X射线衍射分析显示,所制备的介孔CaO-ZrO2固体碱具有高的热稳定性,经700℃焙烧后依然保持完好的介孔结构。CO2-程序升温脱附研究发现,介孔CaO-ZrO2固体碱表面具有3种不同强度的碱性位,并且各种碱性位的数量可通过调节溶胶中的n(Ca)∶n(Zr)加以控制,使产物表面的弱碱位和强碱位数量适应不同催化反应的要求。稳定的介孔结构不仅赋予了该固体碱大的比表面积和发达的孔结构,亦使碱性位更好地分散并暴露在催化剂表面,提高了催化剂的碱密度。进一步阐述了介孔CaO-ZrO2固体碱表面不同碱性位产生的可能机理,并揭示了强碱位的稳定机制。A novel mesoporous CaO-ZrO2 solid base was prepared via sol-gel process. This material overcame drawbacks of conventional single alkali earth metal oxides with low surface area, low base density and poor stability. The as-prepared CaO-ZrO2 solid base possesses typical mesoporous framework and high specific surface area even after calcination at 700℃. CO2-TPD proves that there are three types of basic sites coexisting on the surface. Intensity of each type can be adjusted by controlling n（Ca） ： n（Zr） in the sol-gel process, according to requirements of different reactions. The stable mesoporous structure not only endows high specific surface area and well develops porous structure, but also make basic sites highly dispersed and easy to contact reactants, so basic density and activity of the catalyst increases. Possible mechanisms of the basicity origination and the structure stability were discussed.

关 键 词：介孔结构 固体碱 氧化钙-氧化锆 碱性 催化剂 

分 类 号：TQ032.41[化学工程]