Heterogeneous catalytic strategies on the selective oxidation of glycerol into dihydroxyacetone and glyceric acid: a short review of recent research advances

Glycerol is an important biomass platform molecule, produced as an abundant side-product in the biodiesel industry. The efficient conversion of glycerol through selective oxidation to value-added fine chemicals has been recognized as one of the most promising routes to meet the demand for escalating energy. However, glycerol oxidation usually involves the oxidation of the primary or secondary C–OH of glycerol, the cascade oxidation of intermediates, and the C–C oxidative cleavage of glycerol or intermediates, making it possessing multiple pathways and varied oxidative products. To achieve the selective conversion of glycerol to a single product is of great challenge. The development of efficient catalysts with precisely-designed active sites for the targeted activation of glycerol and the direct conversion to specific oxidative product is the key. In this mini review, we focus on the recent research advances of the selective oxidation of glycerol to the highly-desired C3 value-added chemicals including dihydroxyacetone (DHA) and glyceric acid (GLYA) over heterogeneous catalysts as well as the synergistic catalytic mechanism. The strategies for the targeted and efficient activation of glycerol at the primary or secondary position and the direct conversion of the primary or secondary C–OH and C–H bonds are emphasized. At the end of the article, future challenges and development strategies on the selective oxidation of glycerol are also discussed.