| 摘要 |
Hydrocarbon conversion reactions, e.g. of tertiary butyl benzene to benzene and isobutene and the isomerisation of p-xylene to a mixture of o- and m-xylenes, are effected at 300-500 DEG C. in the presence of a catalyst comprising one or more oxides of aluminium, zirconium, titanium, thorium or beryllium which has been treated with boron trifluoride or a boron trifluoride-diethyl ether complex (see Group III). Reactivation of the catalyst during use may be effected by adding the fluoride to the hydrocarbon feed.ALSO:Catalysts for hydrocarbon conversion reactions, e.g. the conversion of tertiary butyl benzene to benzene and isobutene and the isomerization o gp. xylene to mixtures of o. and m. xylenes, (see Group IV(b)) are prepared by contacting one or more oxides of aluminium, zirconium, titanium, thorium or beryllium with boron trifluoride or a boron trifluoride-diethyl ether complex. The catalyst may also contain silica or magnesia. The oxides are preferably carefully dehydrated, e.g. by heating at 400-750 DEG C. prior to the fluoride treatment. The oxides should also be substantially free from alkali metal compounds and in the case of alumina it may be prepared by the precipitation of hydrated alumina from aluminium nitrate; by the hydrolysis of an aluminium alkoxide with aqueous ammonia or acid; or by the hydrolysis of aluminium amalgam, and in the case of an alumina-silica gel it may be prepared as described in Specification 649,999. Regeneration of the catalyst may be effected by treatment with oxygen at 450-700 DEG C. followed by further fluoride treatment for reactionation. Reactivation may also be effected during use by incorporating the fluoride in the hydrocarbon feed. |
