IMPROVED ISOMERIZATION IN A ZEOLITIC NAPHTHA REFORMING CATALYST USING EXTRA-FRAMEWORK METAL OXIDES

摘要

This application relates to the methods and systems for the conversion of a hydrocarbon feedstock, in particular, naphtha feedstock, into a hydrocarbon product stream containing a high yield of high-octane gasoline. Provided herein a method of preparing a modified zeolitic catalyst comprising: treating a precursor zeolite having a bulk silica-to-alumina ratio and a framework silica-to-alumina ratio with one or more of acid, steam, and a combination thereof under conditions effective to prepare a modified zeolite having a framework silica-to-alumina ratio of at least about 40:1 to about 1000:1 and a bulk silica-to-alumina ratio of at least about 40:1 to about 500:1; and contacting the modified zeolite with a transition metal to form a modified zeolitic catalyst having enhanced isomerization activity as compared to the precursor zeolite. Further provided herein are methods of converting hydrocarbon feed streams into hydrocarbon product streams comprising a high-octane C₅₊ fraction.