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, Caryl─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.