Use of red-mud (MRM) in industrial catalysis: Selective conversion of biomass derived furfural to furfuryl alcohol using Ni-MRM – preparation, characterization and activity studies – elucidating mechanism of hydrogenation using DFT

Conversion of furfural (FFL) to furfuryl alcohol (FOL) using nickel loaded modified red mud (Ni-MRM) was developed with an aim to eliminate toxic Cu-Cr catalyst or precious metal catalyst currently used industrially. Ni-MRM was characterized using various advanced instruments such as XRD, TEM, TPR, BET and XPS. Thermal stability of the material was computed using Kissinger-Akahira-Sonuse (KAS) model. Ni-MRM catalytic activity was studied with variation of parameters. A 15 % Ni-loading on MRM (Ni(15 %)-MRM) shows significant product selectivity (>90 %) in optimized reaction conditions. Density functional theory (DFT) was used for calculation of adsorption energy, charge of the metal at the material active sites. The theoretical calculation shows that H₂ molecule adsorbed upon electron rich Ni surface facilitate bond cleavage to initiate the reaction with adsorbed furfural molecule. Ni-MRM could be reused without significant loss of material catalytic activity for production of furfuryl alcohol. The work also shows effective utilization of properties of red mud for selective transformation of furfural, a bio-renewable material, to value added products.