Liquid phase hydrogenation of biomass-derived ethyl lactate to propane-1,2-diol over a highly active CoB amorphous catalyst

• Ethyl lactate hydrogenation to propane-1,2-diol with a > 98% yield on amorphous CoB
• Dehydration of propane-1,2-diol was suppressed on the optimized sample CoB-0.75.
• Electron-deficient B rich on the surface of CoB-0.75 is a key factor.
• Surface B/Co ratio can be controlled by changing the concentration of Co precursor.

Amorphous CoB alloy catalysts were prepared using chemical reduction method by changing the concentration of cobalt acetate from 0.5 to 1.0 mol/L and examined for the liquid phase hydrogenation of ethyl lactate. The catalyst, prepared with cobalt acetate concentration being 0.75 mol/L, gave a 99.8% selectivity to propane-1,2-diol at a conversion of 98.3%. The catalysts were characterized by XRD, TEM, BET, H2-TPD and XPS. For all the catalysts, Co was electron-rich whereas B electron-deficient, and B was rich on the surface. The change in the concentration of cobalt acetate results in different surface composition of B/Co, various types of Co active sites, and different distribution of particles, which have large influence on activity and selectivity of the catalyst.