Heterogeneous Catalysis for the Hydrolytic Depolymerization of Poly(3-hydroxybutyrate)

Polyhydroxyalkanoates (PHAs) are bio-based and biodegradable polyesters considered promising alternatives to conventional plastics. Among them, poly(3-hydroxybutyrate) (PHB) stands out for its excellent barrier properties, making it attractive for packaging applications. Although PHB is biodegradable, this feature is generally regarded as an end-of-life pathway rather than a true recycling strategy. Therefore, chemical recycling into monomers represents a more effective route for achieving circularity. Despite its potential, conventional hydrolytic processes often require harsh conditions, leading to high energy demand, by-product formation, and difficult purification. Consequently, developing efficient and selective depolymerization strategies under mild and sustainable conditions is essential for enabling circular economy approaches for PHB. In this study, we investigated the catalytic hydrolytic depolymerization of PHB under mild conditions using heterogeneous catalysts.