【摘要】 以共沉淀法制备了Mg -Al复合氧化物催化剂 ,XRD表征结果表明 ,沉淀所得催化剂前体晶相均一 ,为层状Mg6 Al2 (OH) 1 6 CO3·4H2 O水滑石结构。经 5 0 0℃煅烧后得到具有良好酯交换活性的Mg -Al复合氧化物催化剂 ,在常压、(65± 1)℃、4h、醇 /油摩尔比为 6、催化剂加入量 (催化剂质量 /油质量 )为 1 5 %的条件下 ,菜籽油 -甲醇酯交换反应甲酯收率达到 90 %。CO2 -TPD实验表明 ,制备的催化剂比MgO具有更强和更多的碱性位 ,其催化性能与所拥有的碱中心性质直接相关 ,催化剂失活也与碱中心特性变化相对应更多还原

【Abstract】 Mg-Al composite oxides catalyst was prepared by co-precipitating a nitrate solution of magnesium and aluminum.XRD detection showed that precipitate was well crystallized with a typical structure of hydrotalcite brucite-layer.After being calcined at 500 ℃ for 6 h,the precipitate was converted to oxide form.Composite oxides were employed as catalyst for transesterification of rapeseed oil with reasonable activity.Under conditions of atmospheric pressure,(65±1) ℃,methanol/oil mole ratio of 6 and catalyst dosage (catalyst/oil mass ratio) of 1.5%,conversion of oil reached about 90%.Strength and amount of basic site of catalyst was measured by CO 2-TPD mean.Basic sites on composite oxides were larger in number and stronger than those on MgO.The activity of composite oxides correspondingly related to properties of its basic sites.更多还原