SKELETAL ISOMERIZATION OF 1-BUTENE OVER SURFACE-MODIFIED FERRIERITE CATALYSTS

H-ferrierite was treated with oxalic acid to selectively remove extern al acid sites. The treatment led to the reduction of tetrahedrally coo rdinated aluminum ions and the increase of octahedrally coordinated al uminum species and micropore surface area. It was also found that the catalyst treated with oxalic acid is resistant to coking. Over modifie d H-FER, very high selectivity to isobutene is obtained at lower conve rsions suggesting the skeletal isomerization of I-butene is occurring through a mono-molecular reaction mechanism.