Catalytic depolymerization of commercial grade polyurethane (PU) sponge using Ru- supported heterogeneous catalysts

. Plastic waste accumulation in the environment is one main challenge for humanity. Among plastic, Polyurethanes (PU) are a class of specialty polymers with a vast array of applications and a global market volume expected to reach 28 Mton in 2025.[1] Nevertheless, PU recycling is still extremely challenging.[2] Catalytic chemical hydrogenolysis of PU is a promising approach in which PU are depolymerized to amines and polyols with the action of a redox catalyst. [2] Up to date, there are few examples of such approach in literature, mostly focusing on homogeneous catalyst (Ru, Mn, and Ir-pincer) with the addition of mineral bases.[3] In this work, we investigated the hydrogenolysis of a toluene di-isocyanate(TDI)-polyester commercial grade polyurethane sponge (Figure 1) using EtOH as a solvent and Ru/Al2O3 as heterogeneous catalyst