Catalytic cracking of n-decane over NiO–MoO3 modified Pt/ZrO2–TiO2–Al2O3 catalyst with different Al2O3 ratios

Resumo

A series of ZrO₂–TiO₂–Al₂O₃ composite oxides with different Al₂O₃ ratios were prepared by coprecipitation method and used as the supports of Pt/NiO–MoO₃/ZrO₂–TiO₂–Al₂O₃ catalysts. Catalytic activities for n-decane cracking over these catalysts were evaluated under high temperature and high pressure conditions. Physicochemical characteristics of as-prepared catalysts were detected by using automatic adsorption instrument, X-ray diffractometer, temperature programmed reduction, and temperature programmed desorption techniques to characterize the catalysts and supports. The results indicated that the catalyst which contained 60 wt % Al₂O₃ had the largest surface area and pore volume (152.7 m²/g and 0.39 mL/g, respectively), and also it possessed strongest medium and strong acidity as well as medium acidic density. Moreover, the catalyst with 60 wt % Al₂O₃ exhibited better cracking performances compared with the others. The gas yields over Cat3 were 1.5 and 1.2 folds higher than that obtained from thermal cracking at 650 and 700°C, respectively. In addition, the heat sinks were improved 0.27 MJ/kg and 0.25 MJ/kg at 650 and 750°C, respectively.