Nanocrystalline silicalite for catalytic naphtha cracking

A process for selective catalytic cracking of naphtha to light olefins comprising contacting a naphtha feedstock stream with a catalyst at reaction conditions to produce ethylene and propylene, the catalyst comprising a molecular sieve having intersecting 10 membered-ring channels with an average crystal size from about 30 nanometers to about 300 nanometers, and having a silica to alumina ratio greater than about 200.