Advancing biomass valorization with zeolite catalysts: Focus on oxidative transformations

Abstract

The catalytic upgrading of biomass into high-value platform chemicals offers a promising alternative to conventional fossil-based processes, driven by the need for safer, environmentally friendly, and energy-efficient technologies. Zeolites, with their unique structural properties, high surface area, and tunable active sites, are widely used in biomass conversion processes. Metal-modified zeolites, engineered with specific functionalities, exhibit exceptional catalytic activity in key reactions such as glucose isomerization, HMF hydrogenation, fatty acid esterification, and hydrodeoxygenation of phenolics and vegetable oils. This review focuses on the role of zeolites in oxidative biomass transformations, emphasizing their effectiveness in a range of reactions, including functional group oxidation, CC epoxidation, and C-C bond cleavage. We examine the critical features of zeolites -such as porosity, acidity, and metal incorporation- that influence their catalytic performance, especially in terms of selectivity and diffusion limitations. Special attention is given to the oxidative conversion of bio-derived molecules like glucose, HMF and fatty acids into bio-derived acids and epoxides through sustainable, "green" routes. The review concludes by addressing current challenges and exploring future directions for optimizing zeolite-based catalysts for biomass oxidative transformations and the broader bio-based chemical industry.