Conversion of biomass-derived sorbitol to glycols over carbon-materials supported Ru-based catalysts.

Ruthenium (Ru) supported on activated carbon (AC) and carbon nanotubes (CNTs) was carried out in the hydrogenolysis of sorbitol to ethylene glycol (EG) and 1,2-propanediol (1,2-PD) under the promotion of tungsten (WO x ) species and different bases. Their catalytic activities and glycols selectivities strongly depended on the support properties and location of Ru on CNTs, owning to the altered metal-support interactions and electronic state of ruthenium. Ru located outside of the tubes showed excellent catalytic performance than those encapsulated inside the nanotubes. Additionally, the introduction of WO x into Ru/CNTs significantly improved the hydrogenolysis activities and a complete conversion of sorbitol with up to 60.2% 1,2-PD and EG yields was obtained on RuWO x /CNTs catalyst upon addition of Ca(OH) 2 . Stability study showed that this catalyst was highly stable against leaching and poisoning and could be recycled several times.