Upgrading Waste Polylactide via Catalyst-Controlled Tandem Hydrolysis-Oxidation

As plastic waste pollution continues to pose significant challenges to our environment, it is crucial to develop eco-friendly processes that can transform plastic waste into valuable chemical products in line with the principles of green chemistry. One major challenge is breaking down plastic waste into economically valuable carbon resources. This however presents an opportunity for sustainable circular economies. In this regard, a flexible approach is presented that involves the use of supported-metal catalysts to selectively degrade polylactide waste using molecular oxygen. This protocol has several advantages, including its operation under organic solvent-free and mild conditions, simplicity of implementation, and high atom efficiency, resulting in minimal waste. This approach enables the chemical upcycling of polylactide waste into valuable chemicals such as pyruvic acid, acetic acid, or a mixture containing equimolar amounts of acetic acid and formaldehyde, providing a viable alternative for accessing key value-added feedstocks from waste and spent plastics. Highly selective degradation of polylactide (PLA) waste can be achieved through the use of supported-metal catalysts and molecular oxygen in water, process, known as "catalyst-controlled tandem hydrolysis-oxidation", that offers a high flexibility and pathway-specific control. It is also scalable and operationally efficient, enabling complete conversion of PLA waste into valuable feedstocks such as pyruvic acid, acetic acid, or a mixture of acetic acid and formaldehyde through carbon upcycling.image