CeO₂ and La₂O₃ Promoters in the Steam Reforming of Polyolefinic Waste Plastic Pyrolysis Volatiles on Ni-Based Catalysts

Based on the promising results of La 2 O 3 - and CeO 2 -promoted Ni/Al 2 O 3 catalysts in the reforming of biomass pyrolysis volatiles, the performance of these catalysts and the non-promoted one was evaluated in the pyrolysis and in-line steam reforming of polypropylene (PP). The experiments were carried out in a continuous bench scale pyrolysis-reforming plant using two space times of 4.1 and 16.7 g cat min g plastic –1 and a steam/PP ratio of 4. The prepared catalysts and the deposited coke were characterized by N 2 adsorption–desorption, X-ray fluorescence (XRF), X-ray diffraction (XRD), temperature-programmed oxidation (TPO), and transmission electron microscopy (TEM). The Ni/Al 2 O 3 catalyst showed suitable performance regarding pyrolysis product conversion and hydrogen production and led to moderate coke deposition. It is to note that La 2 O 3 incorporation remarkably improved catalyst performance compared to the other two catalysts in terms of conversion (>99%), hydrogen production (34.9%), and coke deposition (2.24 wt %).