With ever increasing concern about white pollution in recent years, more and more countries are tightening restrictions on the application of non-biodegradable plastic products. Exploring new and effective ways to synthesize polymer monomers, e.g., dicarboxylic acids, from biomass is highly desirable and has attracted great attention.<br/>We report a novel catalytic process for levulinic acid (LA) conversion in the presence of molecular oxygen in aqueous solution. Over a binary catalyst of 1RuOx/C and CaO, we obtained exceptionally high selectivity up to 94.7% of 2-hydroxy-2-methyl succinic acid (citramalic acid), which is a high-value dicarboxylic acid containing alpha-hydroxyl group capable to act as a good monomer for biodegradable polymers as shown herein. More interestingly, instead of the methyl group elimination routinely observed in the catalytic oxidation of LA, an unexpected carbon skeleton rearrangement occurred, leading to the branched C5 dicarboxylic acid formation in the one-pot process. The reaction mechanism and synergistic roles of the catalysts in the LA conversion were explored through controlled experiments, isotropic tracer studies and analysis of reaction intermediates.<br/>This process used low-cost reusable heterogeneous catalysts under friendly conditions and obtained ca.95% selectivity of the high-value product. It has high potential to be applied in dicarboxylic acid synthesis from lignocellulosic biomass for biodegradable polymers manufacturing.

Catalytic aerobic oxidation of lignocellulose derived levulinic acid: A novel route to synthesize dicarboxylic acids for bio-based polymers

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.