Catalytic transfer hydrogenation of furfural into furfuryl alcohol over Ni–Fe‐layered double hydroxide catalysts

Transfer Hydrogenation of Furfural to Furfuryl Alcohol Under Microwave Irradiation Using Mixed Oxides

The reaction to obtain furan alcohols is one of the most important in the upgrading of furan derivates. An attractive route is the transfer hydrogenation of furfural using acidic-basic catalysts. In this work, mixed oxides derived from ternary hydrotalcites were employed to obtain furfuryl alcohol from furfural assisted by microwave irradiation. These materials were characterized via X-ray diffraction (XRD), N2 adsorption-desorption isotherms, Fourier-transform infrared (FTIR) and the CO2 temperature-programmed desorption (CO2 -TPD) analyses. The lamellar structure of hydrotalcite-type materials collapses during the calcination process, resulting in the loss of carbonate anions and hydroxyl groups, present in the interlayer space. This leads to the formation of mixed oxides that exhibit larger surface areas. Furthermore, these changes alter the basic nature of these materials, giving rise to the formation of strong basic sites. The reaction was studied using containing Co2+ and Ni2+ in their structure and was then optimized using distinct primary and secondary alcohols as hydrogen donor sources, as well as distinct temperatures and initial concentrations of furfural. The yields to furfuryl alcohol are strongly dependent on the type of Me2+ in layered oxides mainly due to higher basicity and to the donor employed in the reaction. The mixed oxide containing Co2+ showed complete conversion of furfural and higher yields to furfuryl alcohol (>95 %) at short times of reaction (<1 h).

Recent advances in the conversion of furfural into bio-chemicals through chemo- and bio-catalysis

Furfural is a promising renewable platform molecule derived from hemi-cellulose, which can be further converted to fossil fuel alternatives and valuable chemicals due to its highly functionalized molecular structure. This mini-review summarizes the recent progress in the chemo-catalytic and/or bio-catalytic conversion of furfural into high-value-added chemicals, including furfurylamine, C₆ carboxylic acid, i.e., furandicarboxylic acid, furfural alcohol, aromatics, levulinic acid, maleic acid, succinic acid, furoic acid, and cyclopentanone, particularly the advances in the catalytic valorization of furfural into useful chemicals in the last few years. The possible reaction mechanisms for the conversion of furfural into bio-chemicals are summarized and discussed. The future prospective and challenges in the utilization of furfural through chemo- and bio-catalysis are also put forward for the further design and optimization of catalytic processes for the conversion of furfural.