改性2AlCl3-Et3NHCl离子液体催化C4烷基化反应

向2AlCl3-Et3NHCl离子液体中分别加入二硫化碳、丁基硫醇、二甲基硫醚和丙酮,考察了其对离子液体催化异丁烷/2-丁烯烷基化性能的影响.在相同反应条件下,以二硫化碳和丁基硫醇改性的离子液体的催化性能优于未改性离子液体:烷基化产品中的C8组分含量由49.7%分别提高到68.6%和79.2%,TMP(三甲基戊烷)/DMH(二甲基己烷)从0.92分别提高到5.81和4.07.采用乙腈探针红外光谱法测定了离子液体酸性,发现改性后离子液体的路易斯酸强度均有所降低,不同助剂对离子液体的路易斯酸强度的影响也有差别.2AlCl3-Et3NHCl离子液体改性前后的27Al核磁共振波谱表明:Al2Cl7-量的下降导致了改性离子液体酸强度的减弱,其催化性能提高可以归因于加入的助剂在离子液体中形成的新配合物.

Alkylation of C4 in Modified 2AlCl3-Et3NHCl Ionic Liquid

The paper studies the effects of organic additives such as carbon bisulfide(CS_(2)),butyl sulfhydrate(C_(4)H_(10)S),dimethyl sulfide(C_(2)H_(6)S) and acetone(C_(3)H_(6)O)on the catalytic properties of 2AlCl_(3)-Et_(3)NHCl ionic liquids for alkylation of isobutane with 2-butene.The alkylates catalyzed by 2AlCl_(3)-Et_(3)NHCl/CS_(2) and 2AlCl_(3)-Et_(3)NHCl/C_(4)H_(10)S ionic liquids showed significant improvement of product distribution with constitute of C_(8) increasing from 49.7% to 68.6% and 79.2%,the TMP(trimethylpentane)/DMH(dimethylhexane) enhancing from 0.92 to 5.81 and 4.07 respectively in the same reaction conditions.Using acetonitrile as the probe molecule,2AlCl_(3)-Et_(3)NHCl ionic liquids modified with various additives showed difference in their Lewis acidity based on the FT-IR characterizations.From the ~(27)Al NMR investigations,it reveals that the decrease of acid strength of the modified ionic liquids comes from the decrease of Al_(2)Cl~-_(7),and the improvements of catalytic properties of ionic liquids can be attributed to the new complex formed from the additives.