摘要
以硫酸铝和偏铝酸钠为原料,十六烷基三甲基溴化铵(CTAB)溶液为成胶底液,采用水热并流成胶法制备拟薄水铝石,经600℃煅烧后得到γ-Al2O3。通过N2吸附、XRD、SEM、TEM等表征方法考察CTAB加入量、合成pH值等条件对产物比表面积、孔体积、平均孔径、形貌及晶型的影响。结果表明,CTAB作为一种阳离子表面活性剂,能够在酸性和碱性条件下都起到增大比表面积、孔体积、平均孔径和减少团聚的作用,对γ-Al2O3孔结构和形貌也有显著影响;当成胶底液中溶入CTAB的量与理论计算应沉淀出的Al2O3量的摩尔比为0.14∶1时,所制得Al2O3的比表面积、孔体积和平均孔径最大:当pH=8时,达到385.45m2/g、1.14cm3/g和11.9nm;当pH=6时,达到382.43m2/g、0.94cm3/g和9.8nm;在CTAB加入量相同的情况下,碱性反应条件所制得γ-Al2O3的孔体积、平均孔径和晶粒尺寸更大。
Preparation of pseudo boehmite by hydrothermal homogeneous precipitation was carried out in CTAB aqueous solution.After calcinated at 600℃,γ-Al2O3was synthesized.The effects of CTAB addition and pH value on the structure,specific surface area,pore volume and average pore size of prepared samples were characterized by N3 adsorption,XRD,SEM and TEM method.The results indicated that CTAB could increase specific surface area,pore volume,average pore size and reduce agglomeration as cationic surfactant under both acidic and alkaline conditions.It also had a significant impact on the pore structure and morphology of the γ-Al2O3 sample.When n（CTAB） ∶ n（γ-Al2O3） =0.14,specific surface area、pore volume and average pore size of γ-Al2O3 reached the maximum value：at pH =8,they were 385.45m2/g,1.14cm3/g and 11.9nm respectively; at pH =6,they were 382.43m2/g,0.94cm3/g and 9.8nm.With the same content of CTAB,the γ-Al2O3 which was synthesized under alkaline condition had higher pore volume,larger pore diameter and crystalline particle size.
出处
《化工进展》
EI
CAS
CSCD
北大核心
2014年第A01期194-201,共8页
Chemical Industry and Engineering Progress
