Preparation of Pseudo-boehmite and y-Al_2O_3 Support by Neutralization of NaAlO_2 Solution with CO_2

:Pseudo-boehmite (PB) and y-Al2O3 support are prepared by neutralization of NaAlO2 solution with CO2 (mixed gases) on bench scale. PB, typically loosely packed, fibrous particle/aggregate, is obtained by adjusting concentration and flow rate of CO2 and concentration of NaAlO2 solution at a pH level lower than that commonly assumed during neutralization. After calcination at different temperatures, y-Al2O3 supports with different pore volume and different pore size are prepared at different conditions.     

γ-Al2O3负载Au催化剂的制备及其催化CO氧化反应研究

以γ-Al2O3为载体,采用沉积-沉淀法制备出不同Au负载量的系列Au-γ-Al2O3催化剂,利用X射线衍射仪（XRD）对其结构进行了表征,并在实验室小型固定床反应器上对其催化CO氧化反应活性进行了考察.结果表明,在Au负载量小于3％时,Au可很好地分散在载体表面,随着其负载量的增大,Au粒子会发生聚集;沉积-沉淀反应时反应液的最佳pH值为8.0;在一定范围内增加Au负载量,可使催化剂的催化活性显著增强,但当该值大于3％后,反而会对催化活性不利;水蒸气对失活Au-γ-Al2O3催化剂有明显的再生作用,再生后催化剂的活性基本得到恢复,可使CO氧化反应O2转化率大于80％.