ZnO as a simple and facile catalyst for acid-base coordination transformation of biomass-based monosaccharides into lactic acid

Catalytic production of lactic acid (LA) from biomass has attracted increasing attention due to the wide applications of LA. However, the industrial-scale production of LA is seriously limited by the complex synthetic process of efficient catalyst. In this work, we applied commercially available ZnO as a simple and facile heterogeneous catalyst to catalyze the conversion of glucose into LA under hydrothermal conditions. The ZnO possesses abundant strong Lewis acid and base sites and acts as bifunctional catalyst to promote the cascade reactions from glucose to LA, leading to a high yield of 41.5%. The robustness of catalytic process and the wide scope of applicable substrates like monosaccharides and disaccharides further extend the application of hydrothermal biomass conversion using facile catalysts.