Abstract: In order to improve the combustion process of polymer wastes, six kinds of the cerium-based catalysts (Ce-Al₂O₃，Ce-SiO₂，Ce-Fe₂O₃，Ce-NiO，Ce-ZrO₂ and Ce-La₂O₃) were prepared by the impregnation method, the physical chemistry properties were analyzed by XRD, SEM, N₂ adsorption-desorption and O₂-TPD, and the catalytic performance was evaluated by using the low-temperature combustion of polyethylene. The results showed that CeO₂ particles were formed on the surface of Ce-Al₂O₃, which exhibited stronger oxygen adsorption and activation ability than that of polyethylene combustion without catalyst. Compared with polyethylene combustion without catalyst, Ce-Al₂O₃-catalyzed polyethylene combustion could increased both the combustion rate and the combustion efficiency, and thus increased the heat release in polyethylene low-temperature combustion, the selectivity of CO and CO₂ increased by 2.6 times. Ce-Al₂O₃ was reused for 6 times, and still maintained good catalytic performance. The combustion rate and the selectivity of CO and CO₂ in the catalytic polyethylene combustion reaction were higher than that of polyethylene combustion without catalyst.

Key words: polymer wastes, polyethylene, Ce-Al₂O₃, catalytic combustion, recycling