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本研究以氨水、氧氯化锆和三氯化钐为原料,用共沉淀法制得锆和钐的氢氧化物,经低温陈化、过滤、烘干和高温焙烧,制备出SO_4~(2-)/ZrO_2-Sm_2O_3固体超强酸(以下简称SZS)。用流动指示剂法测定其酸度,用IR、XRD对其进行了表征,并将其用于催化氯乙酸和乙醇的酯化反应。结果表明,低温陈化样品的突出优点是酸强度大(H0<-14.5);与SO42-结合得牢;在较宽的温度范围内,具有催化活性的亚稳态的ZrO2四方晶相没有发生相转变,这是其催化活性较高的微观原因。
In this study, ammonia, zirconium oxychloride and samarium trichloride were used as raw materials to prepare zirconium and samarium hydroxide by coprecipitation method. After aging at low temperature, filtration, drying and calcination at high temperature, SO 4 2- ) / ZrO_2-Sm_2O_3 solid superacid (hereinafter referred to as SZS). The acidity of the product was determined by flow indicator method. The product was characterized by IR and XRD, and used to catalyze the esterification of chloroacetic acid and ethanol. The results show that the outstanding merit of low temperature aged samples is that the acid strength is large (H0 <-14.5), combined with SO42-, and the catalytically active metastable ZrO2 tetragonal phase does not occur in a wide temperature range Phase transition, which is a microscopic reason for its high catalytic activity.