Liquid phase hydrogenation of furfural to furfuryl alcohol over the Fe-promoted Ni-B amorphous alloy catalysts

Abstract

Abstract The ultrafine Fe-doped Ni-B amorphous catalyst (Ni-Fe-B) was prepared by reducing mixed FeCl3 and NiCl2 with KBH4 in aqueous solution. At suitable Fe-content (χFe), the Ni-Fe-B amorphous catalyst exhibited much higher activity than the corresponding undoped Ni-B in the liquid phase hydrogenation of furfural (FFR) to furfuryl alcohol (FFA). With the increase of χFe, the activity first increased and then decreased while the selectivity to FFA changed in a contrast way. The Fe-B amorphous alloy itself was inactive for the FFR hydrogenation. The optimum χFe was determined as 0.51, at which the FFA yield reached 100% after reaction for 4 h. Based on various characterizations, the promoting effect of the Fe-dopant was discussed by considering (1) the increase in the surface area, more highly unsaturated Ni active sites, and the more homogeneous distribution of the Ni active sites owing to the presence of Fe2O3 as a dopant; (2) the affinity of the Fe3+ for the oxygen in the carbonyl group which strengthened the adsorption of the CO bond by the catalyst and thus facilitated its hydrogenation; (3) the electron donation of the metallic Fe to the metallic Ni, making Fe electron-deficient while Ni electron-enriched which activated the CO bond towards the hydrogenation.