Investigating the Effects of Modified Zeolite Y on the Degradation of Polypropylene

The effect of zeolite Y on the catalytic pyrolysis of polypropylene (PP) was investigated. In order to reduce the diffusion limitations related to the entry of reactants into and the removal of products from the zeolite cavities, mesoporosity was introduced via a surfactant-templating process. To further improve the catalyst efficiency in lowering the degradation temperature of the polymer and adjust the final product selectivity, two different amounts of calcium (CaO) or magnesium (MgO) oxides were loaded in the catalysts via incipient wetness impregnation. Three different silicon-to-aluminum (Si/Al) ratios (2.55, 15, 30) were tested, and the effects of the modifications on the degradation of PP were investigated. This systematic study proves the enhanced efficacy of the altered catalysts, underlining the synergistic relationship between mesoporosity, acidity, and the incorporation of alkaline-earth metal oxide in the catalytic pyrolysis of polypropylene. The successive modifications cause a significant reduction in the onset and degradation temperatures of the polymer while granting the tuning of the catalyst selectivity toward a narrower product distribution.