A comparative study on liquid phase alkylation of 2-methylnaphthalene with long chain olefins using different solid acid catalysts

摘要

A comparative study has been made over a variety of solid acid catalysts,which include isopoly and heteropoly ions supported on various supports such as zirconia,titania,a large variety of zeolites and a couple of mesoporous materials for liquid phase alkylation of 2-methylnaphthalene with 1-octene.All the catalyst systems were characterized by nitrogen sorption analysis,X-ray diffraction and NH3-TPD.Inspite of their high acid amounts zeolites gave poor catalytic performance due to their diffusional constraints;on the other hand mesoporous materials lacked diffusional constraints but due to their low acid amounts resulted in poor conversions.Isopoly and heteropoly ions supported on zirconia and titania were found to be catalytically active for the reaction due to total surface acidity.Among them,isopolytungstate supported on zirconia exhibited the best catalytic activity and was used for further optimization of reaction conditions.Excellent conversions of all olefins(>92%)with high selectivity of monoalkyl methyl naphthalene(>95%)was obtained under optimized reaction conditions.The catalyst could be recycled for several times without any obvious loss of its activity.