Shock calcined crystalline silica catalysts

摘要

A process for producing a thermally shock calcined crystalline silica comprising (A) precalcining a crystalline silica at a relatively low temperature, (B) very rapidly increasing the temperature of the crystalline silica to a relatively high temperature for a short period of time, and (C) rapidly cooling the crystalline silica. The resulting crystalline silica is catalytically active for hydrocarbon conversion reactions and is particularly selective for the production of para-xylene from a reaction mix of toluene and a methylating agent.