Patent ID: 7323430

Claim:
A method for preparing a catalyst for converting toluene to xylenes, comprising: (i) binding HZSM-5 to silica, to form silica-bound HZSM-5; (ii) silylating the silica-bound HZSM-5, to form silylated silica-bound HZSM-5; (iii) calcining the silylated silica-bound HZSM-5, to form calcined silylated silica-bound HZSM-5; (iv) first washing the calcined silylated silica-bound HZSM-5, to form washed calcined silylated silica-bound HZSM-5; (v) first drying the washed calcined silylated silica-bound HZSM-5, to form dried calcined silylated silica-bound HZSM-5; (vi) steaming the dried calcined silylated silica-bound HZSM-5, to form steamed calcined silylated silica-bound HZSM-5; (vii) treating the steamed calcined silylated silica-bound HZSM-5 with acid, to form acid-treated calcined silylated silica-bound HZSM-5; (viii) second washing the acid-treated calcined silylated silica-bound HZSM-5, to form washed acid-treated calcined silylated silica-bound HZSM-5; and (ix) second drying the washed acid-treated calcined silylated silica-bound HZSM-5, to form the silica-bound HZSM-5 catalyst.