Abstract: A process is described for isomerizing a feed which contains ethylbenzene and xylene, which process comprises the steps of:(a) contacting the feed under ethylbenzene conversion conditions with a particulate first catalyst component which comprises a molecular sieve having a constraint index of 1-12, the particles of said first catalyst component having a surface to volume ratio of about 80 to less than 200 inch.sup.-1 and the contacting step converting ethylbenzene in the feed to form an ethylbenzene-depleted product; and then(b) contacting the ethylbenzene-depleted product under xylene isomerization conditions with a second catalyst component.

Abstract: A process for catalytic cracking of a hydrocarbon feedstock feeds to produce an enhanced yield of C.sub.3 to C.sub.5 olefins comprises contacting the feedstock with a catalyst composition comprising a large pore molecular sieve having a pore size greater than about 7 Angstrom and an additive component comprising a phosphorus-containing zeolite having a Constraint Index of about 1 to about 12 and a crystal size less than 0.2 micron.