Isomerization and disproportionation of m-xylene over zeolite β

The isomerization and disproportionation of m-xylene has been performed over zeolite β samples with Si/Al ratios in the range from 11 to 42. The selectivity for isomerization versus disproportionation and the selectivities among the isomerization and disproportionation products are contrasted with the micropore structures proposed for zeolite β. The isomerization and disproportionation activity of zeolite β depend strongly on the aluminium content, decreasing with increasing framework aluminium content. Maximum activity is found for Si/Al ratios between 14 and 15, while the p/o selectivity remains constant.