负载型磷酸催化剂上合成邻羟基苯乙醚

Synthesis of Catechol Ethylether from Catechol and Ethanol over Phosphoric Acid Loaded Catalyst

制备了以木质炭、二氧化钛、HZSM -2 2、Al2 O3等为载体的负载型磷酸催化剂 ,并考察了这些催化剂在邻苯二酚与乙醇反应合成邻羟基苯乙醚过程中的反应性能。其中以木质炭作载体时 ,邻苯二酚的转化率和邻羟基苯乙醚的选择性分别可达 5 8%和 89% ,催化活性顺序为 :木质炭 >Al2 O3>二氧化钛 >HZSM -2 2。活性炭种类对反应性能的影响顺序为 :煤质炭 >桃核炭 >木质炭 >椰壳炭。以磷酸 /煤质炭系为催化剂 ,最佳反应条件为 :磷酸负载量 (质量分数 ) 4% ,催化剂焙烧温度 2 60～ 30 0℃ ,反应温度 2 60～ 2 80℃ ,载气速率 10～ 42ml/min ,每克催化剂的原料空速 0 33～ 0 5 0ml/(h·g) ,原料摩尔比乙醇 /邻苯二酚 =2～ 5。在最佳反应条件下 ,邻苯二酚的转化率可达 93% ,目的产物的选择性可达 86%。

Supported phosphoric acid catalysts were prepared by impregnation method.Vapor phase oethylation of catechol with ethanol over the prepared catalysts was studied.The catalytic properties were greatly influenced by the kinds of supports,such as charcoal,titanium dioxide,HZSM 22 and alumina etc.The reaction activity decreased in the order of coal,alumina,titanic dioxide and HZSM 22.The active carbons from different sources as carriers were further investigated,where the reaction activity orders was coke>peach stone>peach stone carbon>charcoal>cocoanut charcoal.The optimal reaction conditions using phosphoric acid/coal carbon as catalyst were:content of phosphoric acid,4%(mass fraction);calcination temperature,260～300 ℃;LHSV of the reactant mixtures,0 33～0 50 ml/(h·g);and ethanol/catechol,2～5 (molar ratio).Conversion of catechol and selectivity of guathol reached 93% and 86% respectively and remained essentially unchanged when coal carbon was used as carrier within 10 hours under optimal conditions.