The effect of coke deposition on the deactivation of sulfated zirconia catalysts

Abstract

The formation of coke on sulfated zirconia during the isomerization of n-butane was quantified as a function of time on stream and temperature. The formation of coke was essentially linear with time on stream when the isomerization reaction was performed at 200°C. When the amount of coke deposited reached 0.04 wt.%, the catalytic isomerization activity was observed to decrease to 10% of its initial value. When the reaction temperature was increased, the higher selectivity to cracked products resulted in an increase in coke formation and a higher rate of deactivation. The deactivated sulfated zirconia catalyst could be completely regenerated in air at 450°C. The TGA/FT-IR technique used offers significant advantages over other methods of quantifying coke deposition.