Isobutane/1-Butene Alkylation over a New Composite Catalyst─Sulfated Zirconia Loaded on H Form-Ultra Y Zeolite Catalyst

The composite catalyst SO42–/ZrO2/H-ultra Y zeolite (denoted SZ/HUSY) was prepared and first used in the isobutane/1-butene alkylation reaction. The alkylation performance of the composite catalyst was compared with that of SZ and HUSY. The prepared catalysts were characterized by X-ray diffraction (XRD), Py-IR, NH3-TPD, and so on. The experiment showed that high SZ loading destroyed the crystalline structure and morphology of HUSY, while 5% SZ loading could maintain the favorable structure of HUSY and modified acidity. More important was that 5SZ/HUSY showed better alkylation performances than SZ and HUSY. Much fewer C5–C7 hydrocarbons (i.e., 14% selectivity) than over SZ and fewer C9+ hydrocarbons (i.e., about 16%) than over HUSY were produced, and more C8 hydrocarbons (c.a 70% yield) were formed over 5SZ/HUSY. However, the catalyst still deactivated rapidly. The regeneration performance was evaluated herein. The deactivated catalyst could recover its catalytic activity after several times of reaction–regeneration. The favorable alkylation performances of the prepared composite catalyst 5SZ/HUSY should be attributed to the creation of more medium and strong acid sites and fewer super acid sites, which should result from the interaction between SZ and HUSY. It provided a new way to improve the alkylation performance of solid acid catalysts.