Polyethylene as a Hydrogen Source for C─O Bond Cleavage Via Transfer Hydrogenation

Hydrogenation is widely used in the synthesis of industrial chemicals, yet its reliance on pressurized H₂ poses safety risks and contributes to carbon emissions. Transfer hydrogenation offers an attractive alternative, but it remains constrained by the high cost of typical hydrogen donors. Polyethylene (PE), a major contributor to persistent plastic wastes, is a hydrogen-rich polymer capable of releasing hydrogen during catalytic deconstruction. Here, we propose the use of PE as an inexpensive hydrogen donor for the selective transfer hydrogenation of C─O bonds. We evaluate the transfer hydrogenation of representative substrates, including methanol and lignin model compounds such as anisole and phenoxy ethylbenzene, and show that C─OH, C_aryl─O─CH₃, and β-O-4 linkages undergo efficient and selective cleavage to afford the desired products over acidic zeolites under mild conditions (ambient pressure, <200°C). Control experiments show that the acid sites of the zeolite activate PE to generate hydrogen species while simultaneously polarizing the C─O bonds of the substrates, thereby enabling C─O bond transfer hydrogenolysis. These findings uncover a previously unrecognized hydrogen-transfer pathway between PE and C─O bonds, and provide a basis for developing integrated upcycling strategies for plastic waste and biomass.