Catalytic Epimerization of Glucose to Mannose

Conversion of largely abundant glucose to other commercially important sugars has attracted worldwide attention from both academia and industry. As one of the most important commercialized saccharides, mannose has broad application in the food, cosmetic, and pharmaceutical industries. While mannose is traditionally produced from oceanic biomass using the precipitation technique, recent studies have confirmed that it can also be obtained through catalytic epimerization glucose. Among different promising candidates, Mo- and Sn-based nanomaterials have been showing remarkable performances in catalytic activity. Nevertheless, there still remain several technological obstacles hindering practical applications. Those flaws include low selectivity and poor stability as well as restricted pH operating conditions. In this Perspective, the most updated research advances on catalyst design and the reaction mechanisms for epimerization of glucose will be systematically summarized and critically discussed. The challenges and outlooks will be presented to provide insights for process development for producing commercially valuable saccharides in future biorefineries.