One-Pot Tandem Dehydration-Hydrogenation of Xylose with Formic Acid over Co Catalysts

The transformation of sugars is a sustainable method of production of high value-added chemicals and fuels. Traditional procedures used H2SO4 for sugar dehydration, followed by hydrogenation with fossil-derived hydrogen over noble-metal catalysts, which increased the complexity and cost. In this work, formic acid (FA) served as both acid catalyst for dehydration of xylose and hydrogen donor for hydrogenation of the as-formed furfural (FAL) with N-doped carbon-confined Co (Co-N-C) as a catalyst. A high furfuryl alcohol (FOL) yield of 69.5% was accomplished at 160 degrees C for 5 h. Kinetic studies showed that the apparent activation energy (E-a) over Co-N-C was calculated to be 98.8 kJ/mol. This catalyst was also capable of the one-pot transformation of xylan to FOL and could be reused five times. It is found that the xylose dehydration could be the rate-determining step and coupling xylose dehydration with FAL hydrogenation could accelerate the xylose transformation and the generation of FOL.