Wax isomerization catalyst and method for its production

Abstract

A wax isomerization catalyst is described which comprises a Group VIII hydrogenation metal component on fluorided alumina or material containing alumina which catalyst possesses a surface nitrogen content N/Al ratio of about 0.01 or less determined by X-ray photoelectron spectroscopy, a bulk fluorine content of between about 2 to 10 wt %, a surface fluorine content defined as the amount of fluorine in a layer extending from the outer surface to a depth of about 1/100 of an inch of less than about 3 wt % provided that the surface fluoride concentration is less than the bulk fluoride concentration and an aluminum fluoride hydroxide hydrate peak height of 60 or less determined as the relative amount of hydrate represented by a peak in the X-ray diffraction pattern at 2.theta.=5.66 .ANG. when a hydrate level of 100 corresponds to the XRD peak height exhibited by a standard material. Also described is a method for producing a slack wax isomerization catalyst said method comprising depositing a Group VIII hydrogenation metal on alumina or material containing alumina extrudate, calcining said metal loaded extrudate, fluoriding said material using an aqueous fluorine source solution having a pH of 3.5 to 4.5 to a bulk fluorine level of about 8 wt % or less followed by heating in an air oxygen containing atmosphere or inert gas from ambient to 350.degree. to 450.degree. C. within 3 hours and holding at the final temperature, if necessary, for a time sufficient to reduce the hydrate and nitrogen contents to the aforesaid levels. Alternatively the catalyst can be made using a fluorine solution of pH less than 3.5 to a bulk fluorine level of about 10 wt % or less followed by heating in air or an oxygen containing atmosphere, or inert atmosphere at about 350.degree. to 450.degree. C.