Efficient synthesis of ethanol and propanediol from glucose via a noble metal promoted CuWO4 catalyst

Biomass is the most promising carbon feedstock for producing chemicals and fuels as substitutes for fossil resources. In this work, hydrogenolysis of glucose to ethanol (EtOH) and 1,3-propanediol (1,3-PDO) were carried out over multi-function noble metal promoted CuWO4 (0.1wt.% Ru, Pt and Pd) catalysts using a continuous-flow fixed-bed reactor. Amazingly, the Ru/CuWO4 catalyst presented the best catalytic performance with 84.3% glucose conversion, 63.2% EtOH and 21.2% 1,3-PDO selectivities over 40h reaction. An array of characterization techniques, including XPS, Cu LMM AES, in-situ CO-DRIFTS, NH3-TPD, Py-FTIR, and operando EG-DRIFTS, were applied to reveal the nature of converting glucose into EtOH and 1,3-PDO. It is discovered that the added small amount of Ru tuned the chemical states of W and Cu, resulting in forming the highest content of W5+ and Cu0 on the Ru-promoted catalyst, which improves the glucose hydrogenolysis to EtOH. Besides, the strong Brønsted acid sites (BASs) derived from W6+ contribute to relatively high 1,3-PDO selectivity on Pt/CuWO4 catalyst.