Hydrogenolysis of epoxy resins by a reusable CeO2-supported Ni−Pd bimetallic catalyst toward recycling of epoxy thermosets

Recycling of epoxy composites, one of the most widely utilized thermoset plastics, is of importance for achieving circular economy as demand for the lightweight materials in the field of sustainable technologies is soaring. Although catalytic hydrogenolysis of epoxy resins provides a promising approach to recover valuable fillers and phenolic compounds from the composites, there is a lack of a reusable heterogeneous catalyst for this purpose. Here, we report a robust Ni−Pd bimetallic nanoparticles supported on CeO2 (Ni−Pd/CeO2) for the hydrogenolysis of epoxy resins under mild conditions (180 °C, 1 atm of H2). Mechanistic studies revealed that Pd-induced reduction of Ni2+ to Ni0 is the key for the high efficiency of the bimetallic catalyst. Benefiting from its heterogeneous nature, Ni−Pd/CeO2 can be easily recycled and reused for several times. The catalyst is also applicable to decomposition of carbon fiber-reinforced epoxy resins to recover carbon fibers and bisphenol A, indicating the potential application of our catalyst system toward recycling of epoxy composites.