(632b) Selective Oxidation of Glycerol to Glycolic Acid over Hignly Efficient Fe/TiO2 Catalysts

As biomass energy continues to replace part of fossil fuels, it is of great significance to complete the cheap and efficient conversion of bio-polyols. Glycerol (GLY) is an important component of energy because the production of biodiesel could generate a lot of inexpensive glycerol as a by-product. However, developing efficient catalytic process of non-precious metals remains a challenge during the selective oxidation of glycerol. With different glycerol conversion pathways, oxidation in the liquid phase using metal catalysts has been studied mostly, targeting various value-added products (i.e., 1,3-dihydroxyacetone (DHA), glycolic acid (GLYOA), or tartronic acid (TA)), among which GLYOA has the greatest commercial value and the maximum demand. In particular, its polymer is a new degradable material and has a wide application prospect.

Herein, we prepared Fe catalysts supported by TiO₂ with different crystal forms for the direct oxidation of glycerol to glycolic acid. Through the optimization of system parameters, the Fe-TiO₂ catalyst exhibits excellent catalytic performance with more than 50% yields under mild conditions. It is found that Fe^δ+-Ti_5c-O_2c active species could be generated on the interface of the TiO₂ (101) crystal plane due to the strong interaction of Fe-TiO₂, further promoting the oxidation of glycerol and the subsequent C-C cleavage of oxygen-containing intermediates. The insights here may pave the way to the rational design of non-noble metal catalysts for efficient conversion of biomass under mild conditions.