【摘要】 以拟薄水铝石和三水铝石为原料,氟化铵为添加剂,采用固相法合成片状α-Al₂O₃的过程中,通过SEM、原子吸收光谱法、XRD、压汞法、BET法、吡啶红外吸附等手段研究了NaNO₃添加量对片状α-Al₂O₃结构和性能的影响。研究结果表明,随NaNO₃加入量的增加,片状α-Al₂O₃的微观形貌逐渐由六方片状结构向无规则片状结构转变。高温焙烧导致大量Na挥发。残留在α-Al₂O₃中的Na存在于β-Al₂O₃结构中。α-Al₂O₃表面无酸性中心,β-Al₂O₃的生成并不影响片状α-Al₂O₃的表面酸性。更多还原

【Abstract】 Theα-Al₂O₃ platelets were prepared via the solid-state reactions using pseudo-boehmite and gibbsite as the starting materials,ammonium fluoride as the additive.The effect of the additive amount of NaNO₃ on the property of theα-Al₂O₃ platelets was investigated by SEM,AAS,XRD,mercury intrusion porosimetry,BET,and pyridine-thermal desorption-infrared methods.The results illustrate that the introduction of NaNO₃ leads to the change of morphology ofα-Al₂O₃ platelets from hexagonal laminated structure to irregular structure.Most of Na is volatilized undergoing calcinations at high temperature.The residual Na is in the form ofβ-Al₂O₃ in aggregates ofα-Al₂O₃ platelets.The surface ofα-Al₂O₃ platelets has no acid center,while the existence ofβ-Al₂O₃ has no effect on the surface acidity ofα-Al₂O₃ platelets.更多还原