Catalyst pretreatment in an oxgenate to olefins reaction system

This invention relates to introducing a hydrocarbon into the porous framework of a silicoaluminophosphate molecular sieve. More specifically, this invention is to a silicoaluminophosphate molecular sieve which contains an aromatic compound, and a method for forming said aromatic compound within the porous framework of the silicoaluminophosphate molecular sieve. Disclosed is a crystalline silicoaluminophosphate molecular sieve comprising a porous framework structure and at least one single ring aromatic compound within the porous framework structure. The silicoaluminophosphate molecular sieve is used to convert oxygenate feedstock to olefin product. The olefin product is high in ethylene and propylene content, with a high selectivity to ethylene. The silicoaluminophosphate molecular sieve can be included with a binder and other materials in finished catalyst form.