Promoting Aromatic Hydrocarbon Formation via Catalytic Pyrolysis of Polycarbonate Wastes over Fe- and Ce-Loaded Aluminum Oxide Catalysts

Converting polycarbonate (PC) plastic waste into value-added chemicals and/or fuel additives by catalytic pyrolysis is a promising approach to dispose of solid wastes. In this study, a series of Fe–Ce@Al2O3 metal oxides were prepared by coprecipitation, impregnation, and a direct mixing method. The synthesized catalysts were then employed to investigate the catalytic conversion of PC wastes to produce aromatic hydrocarbons. Experimental results indicated that Fe–Ce@Al2O3 prepared by coprecipitation possessed superior catalytic activity because of its high content of weak acid sites, large pore volume, high surface area, and well dispersion of Fe and Ce active species, leading to an ∼3-fold increase in targeted monocyclic aromatic hydrocarbons compared to that achieved noncatalytically. Moreover, an increase in the catalyst to feedstock (C/F) mass ratio was beneficial to the production of aromatic hydrocarbons at the expense of phenolic products, and elevating the C/F ratio from 1:1 to 3:1 considerably increased the benzene formation as the enhancement factor was increased from 2.3 to 8.8.