Pyrolysis of Polyethylene over Aluminum-Incorporated MCM-41 Catalyst

Aluminum-containing MCM-41 catalysts were synthesized in this study by impregnation of aluminum into hydrothermally synthesized MCM-41. Aluminum was loaded into the porous framework of silica with different Al/Si ratios, using aluminum isopropoxide as the aluminum source. These catalysts exhibited Type IV adsorption–desorption isotherms and had a pore diameter of 2.4 nm. Aluminum species were coordinated tetra- and octahedrally in the structure of catalysts. Diffuse Reflectance Fourier Transform Infrared Spectra (DRIFTS) analysis of the pyridine-adsorbed catalysts revealed the existence of Brönsted acid sites in the synthesized catalysts in addition to the Lewis acid sites. The performance of these catalysts was tested in the degradation of polyethylene using a thermogravimetric analyzer. Pure MCM-41 did not show a significant reduction in the degradation temperature of polyethylene, whereas aluminum-impregnated catalysts were successful in decreasing the temperature.