Al_2O_3/316L整体式催化剂载体的制备与表征

Preparation and characterization of Al_2O_3/316L stainless steel monolithic catalysts carrier

以拟薄水铝石作为γ-Al2O3催化剂载体的前驱体,HNO3为胶溶剂,制备预涂敷铝溶胶浆液。以γ-Al2O3、拟薄水铝石、铝溶胶、聚乙烯醇(PVA)制备二次涂覆浆液。采用预涂敷和二次涂敷两步法,在酸洗后的316 L不锈钢表面浸渍提拉涂敷浆液,经烧结制备出γ-Al2O3/316L整体式催化剂载体。采用SEM,BET,XRD,EDS对载体的形貌特征和物相组分进行了分析,并用超声波震荡法对载体和基体的附着力进行了测试。结果表明:通过酸处理可使基体表面产生多孔结构,经2次焙烧,可以有效地提高载体的附着力,超声波振荡法测定载体平均质量损失率为1.24%。所制备的γ-Al2O3催化剂载体孔径适宜,主要在3 nm和10 nm之间,和常用催化剂载体孔径相近。γ-Al2O3催化剂载体生长均匀光滑,无裂痕,比表面积大,为234 m2/g,孔隙连通性好。

Using boehmite as the precursor of γ-A1203 catalyst carrier and HNO3 as peptizer, a stable primer coating aluminum sol was prepared. Secondary slurry was prepared with γ-A1203, aluminum sol, A1OOH and PVA. Applying primer coating and second coating two-step procedure, A1203/316L stainless steel monolithic catalysts were prepared on acid-treated 316L stainless steel surface after dip-coating and sintering. The appearance feature and phase composition of carrier were characterized by X-Ray diffraction （XRD） , energy dispersive spectrometer （EDS）, scanning electron microscope（SEM）, Brunauer Emmett Teller（ BET）, and the adhesion between matrix and carrier was tested by ultrasonic vibration. The results show that acid treatment and secondary sintering method can effectively improve the adhesion, and the mass-loss rate of the carrier is only 1.24%. The catalyst carrier prepared by this method has good adhesion with substrate. The main pore size is between 3 nm and 10 nm, which matches with the popular catalysts. The carrier cell grows smoothly and evenly, without cracks, and with extensive specific surface area, 234 m2/g, as well as good pore connectivity.