Catalytic activity of metal impregnated catalysts for degradation of waste polystyrene

Waste disposal by degradation to selective and desirable products is the major challenge of our modern society. The current study presents cheap, easily achievable, and novel impregnated catalysts on alumina (Al2O3) support for the degradation of waste polystyrene (WPS) into value added products like toluene, ethylbenzene, styrene monomer, and dimer etc. Al2O3 impregnated catalysts were characterized by SEM, XRD, and N2 adsorption/desorption and their catalytic activities were investigated in the degradation of WPS. The WPS degradation experiments were carried out in a batch reactor at 450 °C. The yield of liquid and styrene monomer was creased with metal impregnated catalysts as compared to nonimpregnated alumina and thermal degradation. Higher yield of liquid and styrene monomer was obtained with 20% Zn–Al2O3 catalyst, 91.54 and 62.88 wt.%, respectively. Impregnation substantially changed the acidity and catalytic properties of alumina in WPS degradation and carbanion may lead to high yield of styrene monomer. The impregnated catalysts performance in terms of high yield of styrene monomer is Zn–Al2O3 > Cu–Al2O3 > Mg–Al2O3 = Al–Al2O3 > Fe–Al2O3 > Al2O3 > thermal.