Abstract: Zinc-substituted aluminophosphate molecular sieves (ZnAPO-11) containing different zinc contents were synthesized using the gel composition n(R)/n(ZnO)/n(Al2O3)/n(P2O5)/n(H2O)=1∶ x∶y∶1.1∶80 (0.5x+y=1) by static hydrothermal method. As-synthesized ZnAPO-11 molecular sieves were characterized by XRD, SEM, N2-adsorption, MAS-NMR and ICP-AES techniques.The results show that ZnAPO-11 molecular sieves with AEL topology are prepared in the range of 0≤n(ZnO)/n(Al2O3)≤0.04. And resultant ZnAPO-11 molecular sieves are of high crystallinity and purity. A regular platelet morphology is observed for the as-synthesized ZnAPO-11 molecular sieves. Experimental data show that Zn as heteroatom is successfully incorporated into the framework of AlPO4-11 and substituted for Al. The n-hexane cracking over ZnAPO-11 was examined under different reaction conditions. It is found that ZnAPO-11 molecular sieves exhibited a significant activity for the n-hexane cracking at 475~550 ℃. Conversion level of n-hexane increased with increasing contact time, and the apparent rates increased with increasing reaction temperature.The first order was determined of the n-hexane concentration. In addition, the dependence of the rates on reaction temperature can be expressed in terms of Arrhenius formula in the whole cracking temperature range.

Key words: Zinc , AEL topology , Aluminophosphate molecular sieves , n-Hexane , Catalytic cracking

摘要： 采用静态水热法, 在活性胶液中各组分摩尔比为n(R)/ n(ZnO)/ n(Al2O3)/ n(P2O5)/ n(H2O)=1 ∶
x ∶y ∶1.1∶80 (0.5x +y =1)的条件下合成了具有不同锌含量的锌铝磷酸盐分子筛(ZnAPO -11), 利用XRD,
SEM , N2 吸附, MAS -NMR 及ICP-AES 等方法对合成的ZnAPO -11 分子筛进行了表征。结果表明, 当0 ≤n
(ZnO)/n(Al2O3) ≤0 .04 时, 可以合成出具有AEL 结构类型的ZnAPO -11 分子筛, 样品具有较高的结晶度和纯
度;晶体形貌均匀, 呈长条形;锌同晶取代了AlPO4 -11 分子筛上的骨架铝。以正己烷为模型底物, 评价了合成的
ZnAPO-11 分子筛的催化裂解反应活性, 研究结果显示ZnAPO -11 在475 ～ 550 ℃具有反应活性, 其中正己烷的转
化率随接触时间的增加而增加, 反应的表观速率常数随反应温度的升高而增加;正己烷在ZnAPO -11 分子筛上的
催化裂解反应的速率方程中的正己烷浓度项反应级数为1, 表观速率常数与反应温度间的关系可用Arr henius 公式
表示。

关键词: 锌 , AEL 结构 , 铝磷酸盐分子筛 , 正己烷 , 催化裂解