Isomerization of n-butane by gallium-promoted sulfated zirconia supported on MCM-41

Abstract

The n-butane isomerization reaction on sulfated zirconia (SZ) supported on MCM-41 mesoporous molecular sieve (SZ/MCM-41) was studied at various reaction temperatures in the presence of hydrogen. The catalytic activity was significantly improved with the addition of an appropriate amount of gallium as a promoter. The best conversion was achieved when the catalyst was promoted by 1.7 wt% gallium and calcined at 680 °C. Although the deactivation of these catalysts in the initial stage was observed the deactivated Ga-promoted SZ/MCM-41 catalysts (SZG/MCM-41) could be completely regenerated in air at 450 °C. The Pt-impregnated SZG/MCM-41 catalyst exhibited higher steady conversion compared with the Pt-free form. These halogen-free catalysts have advantages over other strong acid catalysts, in overcoming corrosion and environmental problems.