BUTANE DISPROPORTIONATION CATALYZED BY SULFATED ZIRCONIA PROMOTED WITH IRON AND MANGANESE

The disproportionation of n-butane (and of isobutane) was catalyzed by sulfated zirconium oxide containing 1.5 wt% Fe, 0.5 wt% Mn, and 4.0 w t% sulfate at 2.0 atm and temperatures in the range of 30-60 degrees C . The reaction accompanies isomerization, which under some conditions is as much as one or two orders of magnitude faster than disproportion ation. The conversion to each of the products increased with time on s tream in a flow reactor, and then declined. The time on stream for max imum conversion was the same for each product. The results suggest tha t the disproportionation and isomerization reactions proceed through a common C-8 intermediate. Rates of the disproportionation reaction wer e determined at the time on stream corresponding to the maximum conver sion at each temperature; for example, the rate of conversion of n-but ane into isopentane at 60 degrees C with an n-butane partial pressure of 0.58 atm was about 1 x 10(-7) mol/(g of catalyst s).