| 摘要 |
Provided herein are monocomponent and hybrid catalyst compositions for use i n steam-cracking of hydrocarbon feeds to selectively produce light olefins. The catalyst compositions being characterized by comprising oxides of aluminum, silicon, chromium, and optionally, oxides of monovalent alkaline metals, and further comprising a binder. Preferably, the catalyst compositions will comprise a catalytic component in accordance with the following formula : (a) SiO2.cndot.(b) Al2O3.cndot.(c) Cr2O3.cndot.(d) alk2 O, with alk being a monovalent alkaline metal. Most preferably, the oxides are prese nt in the following proportions: (a) SiO2: 50-95 wt%; (b) Al2O3: 3-30 wt%; (c) Cr2O3: 2-10wt%; (d) alk2O: 0-18 wt%. Most preferabl y, the alkaline metal will be selected from sodium, potassium and lithium. The binder will preferably be bentonite clay. In hybr id configuration, the first catalytic component is provided as described immediately above. The second catalytic component is selected from a crystalline zeolite or a silica molecular sieve. Also provided in the present invention are methods of making the catalyst compositions.
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