Reductive Depolymerization of Plastic Waste Catalyzed by Zn(OAc)2 ⋅ 2H2O

Abstract

Plastic pollution is one of the biggest problems all over the world. Beyond change/awareness of consumer behavior, there is an urgent need to search for efficient, economical and environmentally friendly catalysts for the valorization of plastic waste to value‐added compounds. This work describes the reductive depolymerization of several types of plastic waste into value‐added compounds, including 1,6‐hexanediol, 1,2‐propanediol, p‐xylene and tetrahydrofuran, in good yields using the eco‐friendly, air‐stable, commercially available and very cheap catalyst Zn(OAc)₂ ⋅ 2H₂O. This is the first example of the reductive depolymerization of polyester waste catalyzed by a zinc catalyst. Moreover, the catalytic system silane/Zn(OAc)₂ ⋅ 2H₂O was successfully applied to the reduction of polycaprolactone (PCL) on the gram scale with good yield and also to the selective reductive depolymerization of plastic mixtures. Finally, this work demonstrated that the catalyst Zn(OAc)₂ ⋅ 2H₂O can be used in at least 7 cycles with good yields.