Catalyst Design for Shape Selective Methylation of 2-Methylnaphthalene

研究了2-甲基萘与甲醇择形烷基化合成2，6-二甲基萘的反应条件。在各种沸石中，MFI型沸石ZSM-5对2，6-二甲基萘表现出较高的选择性。为此，本文对具有MFI结构的HZSM-5分子筛和金属硅酸盐的烷基化反应进行了详细的研究。对具有MFI结构的催化剂进行了改性，改变了催化剂的酸强度和孔尺寸。此外，还对沸石微晶外表面失活催化剂进行了改性。当外表面被2，4-二甲基喹啉选择性毒化时，2，6-二甲基萘的生成具有很高的选择性。此外，为了制备高性能的选择性生成2，6-二甲基萘的催化剂，有效地削弱了酸强度，保持MFI结构的孔尺寸恒定，如果可能，保持更宽的孔尺寸。

Shape selective alkylation of 2-methylnaphthalene with methanol to produce 2,6-dimethylnaphthalene was studied. Among various zeolites, MFI type zeolites, ZSM-5, exhibited a high selectivity to 2,6-dimethylnaphthalene. Therefore, detailed study on the alkylation over HZSM-5 zeolites and metallosilicates with MFI structure was carried out. The catalysts with MFI structure were modified to vary the acid strength and pore dimension. Moreover, the modification of the catalysts for inactivation of solely external surfaces of zeolite crystallites was performed. A high selectivity for the formation of 2,6-dimethylnaphthalene was achieved on ferrisilicate especially when the external surfaces were selectively poisoned by 2,4-dimethylquinoline. Moreover, in order to prepare a high performance catalysts for selective formation of 2,6-dimethylnaphthalene it is effective to weaken the acid strength keeping the pore dimension of MFI structure constant, or if possible, wider.