γ-Al2O3载体制备中连续化水洗对拟薄水铝石织构的影响

探讨了γ-Al₂O₃载体制备中连续化水洗取代间歇式水洗后对前驱物拟薄水铝石织构的影响。采用X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热分析仪(DTA)、氮吸附脱附仪和汞孔计等分析测试手段研究了水洗连续化对物质晶相、粒径、结晶度以及孔结构的影响。实验结果表明，连续化水洗不影响拟薄水铝石的物相组成以及一次粒子的粒径和形状，而二次粒子粒径及其聚集体的大小与间歇式水洗有明显差异。借助差热分析以及Al₂O₃·nH₂O中化学结晶水n值的计算，对拟薄水铝石的有序度进行了考察，发现连续水洗有利于拟薄水铝石从无序向有序的进一步演化。

Effects of successive washing on structure and properties of pseudoboehmite in preparation of γ-Al2O3

Influences of successive washing instead of batch-wise washing on crystalline phase, particle size，crystallinity and pore structure in preparation of γ-Al₂O₃ were investigated using XRD, SEM,TEM and thermal analyzer(DTA). The results showed that neither the crystalline composition nor the shape and size of primary particles of pseudoboehmite were affected by successive washing. But much difference in size of the secondary particles and their aggregates was observed between successive washing and batch-wise washing. Differential thermal analysis(DTA) and calculation of n in Al₂O₃· nH₂O were used to investigate the order of pseudoboehmite. It was found that successive washing favored transition of the crystal structure from disorder to order.