SHAPE SELECTIVE DISPROPORTIONATION OF METHYLNAPHTHALENE ON ZSM-5 CATALYST

Article abstract of DOI:10.1135/cccc19920909

The conversion of 2-methylnaphthalene (2-MN) was studied at atmospheric pressure in a flow-type fixed bed reactor using H-Y, H-beta, H-mordenite, H-ZSM-5, H-ZSM-11 and H-ZSM-48 as catalysts.H-Y and H-beta exhibited high activities for disproportionation and isomerization of 2-MN.H-Mordenite and zeolites having medium size pores were active for the conversion of 2-MN which was mainly isomerized to 1-MN.The low disproportionation activities of these zeolites resulted from their shape selective properties.Disproportionation of 2-MN on the zeolite catalysts gave 2,6- and 2,7-dimethylnaphthalenes (DMN) in higher proportions than the thermodynamically attainable level.H-ZSM-5 was the most selective catalyst to produce these DMN isomers among the zeolite catalysts tested, although 2,7-DMN was formed in a higher proportion than 2,6-DMN.On H-mordenite catalyst, 2,6-DMN was more selectively formed than 2,7-DMN.The selectivity for 2,6-DMN against 2,7-DMN increased with increasing SiO2/Al2O3 ratio of H-mordenite.It is suggested that the composition of DMN isomers produced by disproportionation of 2-MN depends on the acid strength as well as on the shape selective properties of zeolites used.