浸渍法制备高选择性1-丁烯齐聚催化剂Fe_2O_3·SO_4^(2-)/γ-Al_2O_3

Preparation of High Selectivity 1-Butene Oligomerization Catalyst Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 by Impregnation Method

通过分步浸渍法制备Fe_2O_3·SO_4^(2-)/γ-Al_2O_3催化剂,并用于催化1-丁烯齐聚反应,考察了催化剂制备条件和反应条件对催化性能的影响,并与Fe_2(SO_4)_3/γ-Al_2O_3催化剂进行性能比较。结果表明,在0.96 MPa、60℃、液时空速为5h-1的反应条件下,采用Fe负载量为6%、SO_4^(2-)负载量为1.2 mmol/g(γ-Al_2O_3)的Fe_2O_3·SO_4^(2-)/γ-Al_2O_3催化剂,1-丁烯齐聚反应的转化率达到68.0%,二聚物选择性为95.0%。α-Fe_2O_3是催化1-丁烯齐聚反应的活性组分,并能提高二聚体选择性;此外,α-Fe_2O_3晶相与SO2-4的相互作用对其催化1-丁烯齐聚反应的活性有重要影响,γ-Al_2O_3与SO_4^(2-)的相互作用也对催化活性有一定的影响。Fe负载量为6%的Fe_2O_3·SO_4^(2-)/γ-Al_2O_3催化活性最高,此时NH_3-TPD结果显示,催化剂只存在较弱的酸中心和适中的酸量。

Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 catalyst was prepared by step-impregnation method,and its catalytic performance for 1-butene oligomerization was studied and compared with Fe_2(SO_4)_3/γ-Al_2O_3 catalyst.The influences of the preparation and reaction conditions on the catalytic activity of Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 for 1-butene oligomerization were investigated.The results showed that,on the reaction condition of pressure of 0.96 MPa,reaction temperature of 60℃ and liquid hourly space velocity of 5h-1,with the Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 of 6% Fe loading and 1.2mmol/g(γ-Al_2O_3)SO2-4loading as catalyst,the conversion rate of 1-butene oligomerization reached 68.0% and the dimerization selectivity was 95.0%.α-Fe_2O_3 is an active component in catalytic 1-butene oligomerization and high dimerization selectivity can be obtained.In addition,the interaction betweenα-Fe_2O_3 crystal phase and SO2-4had an important influence on the catalytic activity of Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 in 1-butene oligomerization and the interaction betweenγ-Al_2O_3 and SO_4^(2-) also had some influence.Catalyst activity of Fe_2O_3·SO_4^(2-)/γ-Al_2O_3 was maximum with 6% Fe loading,and its NH_3-TPD results showed there existed weak acid sites and only a moderate amount of acid.