Patent ID: 7713898

Claim:
A method of modifying a zeolite catalyst, the method comprising: contacting a ZSM-5 zeolite having a SiO 2 /Al 2 O 3 mole ratio of from about 200 or more with an aqueous solution of a phosphorus compound; and removing water from the phosphorus treated ZSM-5 zeolite; and heating the phosphorus treated zeolite at a temperature of 250° C. or higher; and wherein the resulting phosphorus treated ZSM-5 zeolite has a SiO 2 /Al 2 O 3 mole ratio of from about 200 or more, a phosphorus content of at least 8% by weight of zeolite and has multiple phosphorus species exhibited by at least three 31 P MAS NMR peaks with maxima at about 0 ppm to about −50 ppm.