The effect of Al2O3-promotion of sulfated zirconia on n-butane isomerization: An isotopic transient kinetic analysis

This paper reports on an investigation using steady-state isotopic transient kinetic analysis (SSITKA) of Al2O3-promotion of sulfated zirconia (SZ) for n-butane isomerization. SZ promoted with Al2O3 showed an approximately 30% increase in n-butane isomerization activity at 250 °C. The average surface residence times of the reaction intermediates on unpromoted and Al2O3-promoted SZ measured by SSITKA suggest that the active sites on both catalysts were identical. There was, however, a significant increase in the concentration of surface intermediates upon Al2O3-promotion, leading to the increased activity. Al2O3-promotion also appeared to improve catalyst site stability resulting in a slower rate of deactivation.