| 摘要 |
Catalytic cracking catalysts, the process of their preparation and the process of their use. Cracking catalysts are disclosed for improving the octane number of gasoline products. The catalysts comprise a zeolitic aluminosilicate having a mole ratio of oxides in the dehydrated state of (0.85-1.1) M2/nO:Al2O3:xSiO2 wherein M is a cation having a valence of "n" and "x" has a value greater than 6.0 to about 11.0; has an x-ray powder diffraction pattern having at least the d-spacings of Table A; has extraneous silicon atoms in the crystal lattice in the form of framework SiO4 tetrahedra; has between greater than zero to less than 5.0 percent by weight, expressed as the oxide, of at least one rare earth cation selected from the group consisting of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium; and less than 1.2 weight percent Na2O based on the weight of the aluminosilicate.
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