Hydrogen bonds regulation to enhance catalytic C-C bonds cleavage of polylactic acid wastes in H2O to produce H2

Abstract

Polylactic acid (PLA) as the biodegradable plastic is the currently highest production among the global bio-based plastics. In comparison to the natural degradation of PLA with a substantial period of time, the development of a novel transformation process for the upcycling of PLA plastic, which combined with H2O to green H2 and CO2, is of great significance. Herein, a hydrogen bonds regulation strategy with Ni-Fe catalyst is proposed to achieve the direct transformation of PLA plastic wastes in H2O to CO2 and H2 at 310 °C. The fabricated Ni-Fe catalyst enables the cleavage of intramolecular hydrogen bond in PLA-derived oxygenates to convert various PLA plastic wastes in H2O, and H2 production reaches up to 62.6 mmol "g" _"plastic" ^"-1" accompanied with H2 selectivity of 93.5%. Further reaction pathway reveals that, compared to Ni catalyst, the incorporated Fe into Ni greatly enhances the catalytic cleavage of intramolecular hydrogen bonds, which further accelerates C-C bonds cleavage. And it displays the tremendous production capability for hydrogen production during ten cycles. This approach provides an innovative solution for upgrading PLA wastes to sustainable hydrogen and contributes to the low-carbon future.