Xylenes are important feedstock for industrial production of terephthalic acid,isophthalic acid, dimethyl terephthalate, polyester resins, and the synthesis of vitamins or other pharmaceutical products.Nowadays, most xylenes are mass produced in industrial scale via either naphtha catalytic reforming or toluene disproportionation.An alternatively route to produce xylenes is through the methylation of toluene or benzene, zeolites are preferred solid acidic catalyst for their shape-selectivity.