镍基催化剂表面氧覆盖度对糠醛选择性加氢路径的调控规律研究OA

The selective hydrogenation of biomass-derived compounds is pivotal for the synthesis of high-value-added chemicals.The controllable hydrogenation in furfural for furfuryl alcohol or tetrahydrofurfuryl alcohol is highly desirable yet challenging.In this study,Ni2Al-LDO(layered double oxide)metal oxide catalyst featuring highly dispersed surface NiO was synthesized via a structural topological transformation using layered double hydroxides.The catalyst exhibited excellent performance in the hydrogenation of furfural,achieving 91.42％yield of furfuryl alcohol(FOL)at 160 ℃ and 1.4 MPa H2.Gradual reduction of Ni2Al-LDO produced Ni/NiO mixtures,enabling tunable shift from FOL to tetrahydrofurfuryl alcohol(HFOL)as the NiO content decreased and the Ni content increased.After a two-hour reduction at 700 ℃,the HFOL yield reached 93.95％.CO2-TPD,NH3-TPD and FT-IR measurements revealed that variations in reduction degree on nickel influenced the adsorption behavior of furfural.NiO species could only adsorb the C=O group of furfural,isopropanol serves as the hydrogen source,and furfural undergoes hydrogenation to form furfuryl alcohol following the MPV conversion pathway.Whereas the flat adsorption mode on the metallic Ni surface facilitated the simultaneous adsorption and activation of both the furan ring and the carbonyl group of furfural.In addition,the hydrogen sources of the reaction systems also differ:the Ni2Al-LDO catalyst is only capable of activating isopropanol,with the reaction proceeding via the MPV mechanism;in contrast,Ni2Al-LDO-700 can activate both H2 and isopropanol,where H2 serves as the primary hydrogen source.This work elucidates a clear structure-activity relationship centered on the metal oxidation state and provides a practical reduction-engineering approach for designing adaptable catalysts in biomass upgrading.