微波促进稀土固体超强酸S_2O_8~(2-)/Sb_2O_3/La~(3+)催化合成乙酸苄酯

采用金属醇盐水解法制备了稀土固体超强酸S_2O_8~(2-)/Sb_2O_3/La~(3+)催化剂,并用Hammett,IR,DTA/ TGA,XRD等手段对催化剂进行了表征。以稀土固体超强酸S_2O_8~(2-)/Sb_2O_3/La~(3+)为催化剂、乙酸和苯甲醇为原料,在微波辐射下合成了乙酸苄酯。考察了催化剂制备条件及合成条件对酯化率的影响,催化剂最佳制备条件:用1.5 mol/L的(NH_4)_2S_2O_8和2.71%La(NO_3)_3混合溶液浸渍前体氧化物Sb_2O_3,经110℃烘干,于500℃焙烧3 h。最佳合成条件:n(苄醇):n(乙酸)=2:1,催化剂用量0.6 g,辐射时间25 min,微波功率528 W,酯化率93.8%。用IR、~1H NMR等手段对产物进行了确证。

CATALYTIC SYNTHESIS OF BENZYL ACETATE WITH S_2O_8~(2-)/Sb_2O_3/La~(3+) UNDER MICROWAVE IRRADIATION

A solid super acid S_2O_8~(2-)/Sb_2O_3/La~(3+) catalyst was prepared by the hydrolysis of metal alcoholate and characterized by Hammett indicator,IR,DTA/TGA,and XRD.Benzyl acetate was synthesized with acetic acid and benzyl alcohol as raw material and the solid super acid as catalyst under microwave irradiation.The effects of catalyst preparation and synthesis conditions on the degree of esterification were investigated.The optimum conditions for the preparation of the catalyst were found as follows:impregnation of Sb_2O_3 with mixed solution of 1.5 mol/L(NH_4)_2S_2O_8 and 2.71% La(NO_3)_3,dried at 110℃,followed by calcination at 500℃for 3 h.The optimum conditions for the reaction were found as follows:n(alcohol):n(acid)=2:1,0.6 g catalyst,power of microwave 528 W,reaction time 25 min,with the yield of 93.8%.The product structure was identified by methods of IR and ~1H NMR.