| 摘要 |
A method for prolonging the useful life of para-selective modified zeolite catalysts, said zeolites having a silica to alumina mole ratio of at least about 12, a constraint index of about 1-12 and having been modified by the addition thereto of a minor proportion of a difficultly reducible oxide. The selective catalyst is maintained at temperatures of at least about 50.degree.C or, alternatively, in an atmosphere substantially free of moisture. |
