Efficient Conversion of Biomass-Derived Furfural to Tetrahydrofurfuryl Alcohol over Co3O4-C Nanocomposite Catalyst at Mild Conditions

Due to the depletion of fossil fuel resources, catalytic conversion of biomass into liquid fuels and valuable compounds has become an attractive field of research. Tetrahydrofurfuryl alcohol (THFAL) is an important platform molecule in both industrial and pharmacological fields, and catalytic hydrogenation of furfural (FA) to THFAL is a sustainable process. However, an active and stable catalyst for the direct hydrogenation of FA to THFAL under milder conditions is still a challenge. Accordingly, herein, we investigated a high-valence metal catalyst (Co3O4-C) for the hydrogenation of FA to THFAL using sodium borohydride (NaBH4) as the H source. Under optimal reaction conditions (that is, 0.05 g Co3O4-C-700 in an aqueous solution, 5 mmol NaBH4, 60 degrees C, and 3 h), 88.5 % THFAL was produced over Co3O4-C-700. The kinetic study revealed that furfuryl alcohol was generated as an intermediate during the hydrogenation of FA. Additionally, the reaction followed pseudo-first order kinetics, and the reaction rate constant (k) values were .80, 3.41, 3.45, and 5.55 h(-1) at 30, 40, 45, 50, and 60 degrees C, respectively. From the slopes of the Arrhenius plot, the activation energy was determined to be 22.02 kJ mol(-1), indicating high activity of the catalyst for the reaction. Moreover, Co3+ and smaller sizes of Co3O4 nanoparticles contributed to the activity of Co3O4-C-700. We believe that the metal oxide catalyst developed herein can be used for various biomass conversions.