Mixed oxide and phosphoric oxide catalysts are prepared and used to increase the yields of light alkenes (especially ethylene and propylene) from steam cracking of light hydrocarbons, especially light naphtha. The oxide and phosphoric oxide catalysts are of general formulas CrZrjAkOx and CrZrjAkPlOx, in which: (1) j is equal to or between 0.5-120, k is equal to or between 0-50 (for oxides), (2) j is equal to or between 0.1-50, k is equal or between 0-30, and l is equal or between 0.5-100 (for phosphates), and (3) A is a transition metal selected from Ti, Nb, Mo, V, Co, Ni, W, Fe, and can include rare earth metals. The metal precursors can be prepared from such precursors as sulfates, nitrates, oxalates, halides, chlorides, salts, acids, oxides, hydroxides, and alkoxides. Steam cracking is typically carried out at 600-1000 degrees, steam-hydrocarbon weight ratio 0.3-1.0:1, and space velocity 1-20 h-1.
Please note: Titles and abstracts for patent records in CAplus are routinely enhanced to better describe the claimed invention. In this example, CAS enhanced both the abstract and title using additional information found in the patent. The original title of the U.S. publication is Oxide catalyst and phosphoric oxide catalyst for hydrocarbon steam cracking, method for preparing the same and method for preparing olefin by using the same. For the CAplus record, this title was enhanced to read: Mixed oxides and mixed oxides-phosphates as steam cracking catalysts for enhanced yields of light olefins.