| 摘要 |
<p>Catalytic cracking processes wherein the cracking catalysts are prepared by: (1) contacting a mixture of a large pore zeolite and an inorganic oxide matrix at effective conditions of temperature, pH and time with a fluoro salt; and (2) ammonium exchanging the product of step (1) to provide a catalyst having less than 0.3 percent by weight Na2O, based on total catalyst weight, or less than 2.0 percent by weight of the zeolite employed in the catalyst. Optionally, the zeolite used is provided with an effective amount of at least one cation selected from the class consisting of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, lutetium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and ytterbium.</p> |
