Amorphous phosphorus oxynitride as a robust catalyst for steam-free direct dehydrogenation of ethylbenzene to styrene: effect of calcination temperature

A metal-free catalyst of phosphorus oxynitride (simplified as PNO) for direct dehydrogenation (DDH) of ethylbenzene was synthesized via calcinating hexachlorocyclotriphosphazene (HCCP) under an ammonia–oxygen atmosphere.