前驱体合成方法对γ-氧化铝性质的影响研究

Effects of precursor synthesis methods on properties of γ-Al_2O_3

γ-氧化铝是一种应用广泛的催化剂载体,其性质对很多催化剂具有至关重要的影响。采用氮气吸附-脱附、X射线衍射、热重-差热分析、扫描电镜、氨气程序升温脱附以及吡啶红外等方法对γ-氧化铝及其前驱体进行表征,研究拟薄水铝石制备方法对γ-氧化铝性质的影响,并考察了其对加氢精制反应性能的影响。结果表明,拟薄水铝石制备方法不同,其孔结构和表面形貌各具特点,晶相纯度和结晶度也存在差异,对γ-氧化铝孔结构及物相也有较大影响。不同方法制备的载体样品表面酸量及酸强度分布存在差异,直接影响催化剂的性能。

As a widely-used support for catalysts, γ-Al2O3 has a crucial influence on many catalysts.The properties ofγ-Al2O3and its precursor were characterized by N2 adsorption-desorption, XRD, TGA/DSC, SEM, NH3-TPD, and Py-IR.The influences of the preparation methods of pseudo-boehmite on the properties of γ-Al2O3were studied and their effects on the properties of hydrorefining reaction were also investigated.Results showed that the pore structures and surface morphologies of the samples made from different synthesis methods had their own characteristics, and the purities of crystal phase and crystallinities of the samples were different as well.Therefore, they also had a large effect on the pore structures and phase of γ-Al2O3.The differences of surface acid amount and intensity distribution of the samples directly influenced the catalytic activity of the catalysts.