【摘要】 研究了由硬水铝石分解制备高表面α Al2 O3的生成条件 ,以及煅烧温度、时间对高表面α Al2 O3性质的影响规律和添加Si对高表面α Al2 O3热稳定性的影响。结果表明 ,由硬水铝石分解制得的高表面α Al2 O3具有孔容大、孔径小、α相结晶不完善的特点 :高温下高表面α Al2 O3不稳定 ,随煅烧温度增加 ,表面氧原子迁移加剧 ,微孔烧结 ,比表面降低。硅组分的添加能在一定程度上抑制表面氧原子的迁移 ,使α Al2 O3的α相保持完善和抑制微孔的烧结 ,从而增强了高表面α Al2 O3的热稳定性。更多还原

【Abstract】 The forming condition of high surface area (HSA) α Al 2O 3 from diaspore decomposition,the influences of calcination temperature and time on its properties and the effects of additive Si on its thermal stability were studied.The results showed that HSA α Al 2O 3 prepared from diaspore decomposition had high pore volume and small pore size,yet it was unstable at high temperature,and,with calcination temperature increasing,the surface oxygen atoms migrated more frequently,and that brought about the sintering of micropores and reducing of surface area.It seems that the addition of Si suppresses migration of surface oxygen,keeps the a phase perfect and restrains the sintering of micropores,so the thermal stability of HSA α Al 2O 3 increases.更多还原