Superacid catalysis of light hydrocarbon conversion. Tenth quarterly report, January 1, 1996--March 31, 1996

Transition metal promoters markedly increase the activity of sulfated zirconia for isomerization of butane. Data presented here demonstrate the effects of the promoters zinc, iron, and manganese; none of these is as effective as the iron/manganese combination. The effects of feed impurities (olefins and/or isobutane in n-butane) are consistent with those described in the preceding quarterly report: they lead to an improvement in catalytic activity. These observations are inferred to be of practical importance; they indicate the benefit of the impurities in increasing butane conversion. The product distribution data show that reactions accompanying isomerization and disproportionation are more important with some promoters (e.g., iron) than others (e.g., zinc). The data demonstrate that the iron- and manganese-promoted catalyst can be regenerated at least sever times with negligible loss of activity (within the experimental error). To apply this catalyst or a related catalyst industrially, it seems very likely to be necessary to reduce the rate of deactivation substantially and/or to regenerate the catalyst through many cycles