Inclusion of Zn into Metallic Ni Enables Selective and Effective Synthesis of 2,5-Dimethylfuran from Bioderived 5-Hydroxymethylfurfural

Abstract

5-Hydroxymethylfurfural (HMF) is an important platform chemical derived from C6 sugars and cellulose. The formed 2,5-dimethylfuran (DMF) via hydrogenolysis of HMF was denoted as a promising and sustainable fuel candidate. The further improvement of DMF yield is the central premise of this work, which is based on the elucidation of the relationship between catalytic performance and active sites. Herein, a NiZn alloy catalyst was formed through Zn inclusion to Ni by controllable reduction of the NiZnAl hydrotalcite-derived NiO–ZnO–Al2O3 mixed oxide. The combination of temperature-programmed reduction (TPR), in situ X-ray diffraction (XRD), CO-adsorbed infrared spectroscopy (CO–IR), and X-ray photoelectron spectroscopy (XPS) revealed that the surface of the NiZn catalyst was composed of β1-NiZn while the bulk was composed of α-NiZn. Moreover, the surface Ni atoms were geometrically isolated by Zn atoms and modulated to be electron-rich. Finally, the rate of C═O/C—O hydrogenolysis over C═C/C—C hydrogenation f...