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Holey layered HEO nanocrystals with surface FLP sites have been synthesized via a temperature-variable topological transition. Merits of high-entropy oxides and nanoscale effects are favored yielding a superior catalytic performance toward the transfer hydrogenation (CTH) reaction of biomass-derived carbonyl compounds at mild conditions. Mechanistic investigation indicates that the formation of active regions between FLPs provides a stronger driving force for dissociating alcohols and activating the carbonyl groups of substrates, accounting for the enhanced catalytic activity. [Display omitted] • Holey layered high entropy oxide (HEO) nanocrystals with abundant frustrated Lewis pairs (FLPs) have been synthesized. • Combination of HEO properties and nanoscale effect drives FLPs concentrations of as-obtained catalyst up to 585.4 μmol/g. • Catalysts display superior catalytic activity and cycling performance toward the CTH reaction under mild conditions. • FLPs provide stronger driving forces for dissociating alcohols and activating the carbonyl groups of substrates. • Direct hydrogen transfer dominates the catalytic reaction over holey lamellar HEO catalysts. Creating frustrated Lewis pairs (FLPs) on stable high-entropy oxides (HEOs) is a new challenge, and also an uncultivated field in catalysis. Herein, holey layered HEO spinel nanocrystals with rich FLPs were synthesized via a temperature-driven topological transition. The FLPs on the surface of HEO spinel nanocrystals are created by oxygen vacancies (Lewis acid sites) and proximal surface hydroxyls or surface lattice oxygen (Lewis base sites). Rich FLPs furnish HEO nanocrystals a superior activity towards the catalytic transfer hydrogenation reaction of biomass-derived carbonyl compounds at mild conditions. The active regions in between FLPs provide a strong driving force for dissociating alcohols and activating carbonyl groups of substrates, as evidenced by the attenuated total reflectance-infrared spectroscopy (ATR-IR) analysis, which enhances the catalytic activity. This work develops a new kind of hydrogenation catalysts and provides a perspective for creating solid FLPs. [ABSTRACT FROM AUTHOR]

A stable and easily separable Fe 3 O 4 -12 nanoparticles exhibited the desired catalytic performance in the catalytic transfer hydrogenation reaction of furfural to furfuryl alcohol with 2-propanol as the hydrogen source. Moreover, a feasible flowchart from xylose to FOL was designed. Utilizing the process can realize the regeneration of biomass resources, the reuse and recycling of catalysts and solvents, and minimize the amount of solvents and pollutant emissions. • Magnetic Fe 3 O 4 -12 nanoparticles exhibited excellent catalytic performance for the CTH reaction of FAL to FOL. • A feasible flowchart from xylose to FOL was designed, which can realize the valorization of biomass resources. • Fe 3 O 4 -12 nanoparticles have good recyclability and universality for different carbonyl compounds. Magnetic Fe 3 O 4 -12 nanoparticles, an easily separable heterogeneous catalyst, exhibits high catalytic performance in the catalytic transfer hydrogenation (CTH) reaction of biomass-derived furfural (FAL) to furfuryl alcohol (FOL) with 2-propanol (2-PrOH) as the hydrogen source (90.1 % FOL yield at 160 °C for 5 h). Comparing Fe 3 O 4 nanoparticles with different particle sizes found that the smaller the nanoparticles, the larger the BET surface area, pore volume and pore diameter, resulting in more acid-base active sites through BET, SEM, TEM, NH 3 -/CO 2 -TPD and other characterizations. Moreover, a scaled-up CTH experiment of FAL and a stepwise reaction from xylose to FOL verified that the catalytic system has great industrial application prospects. A feasible flowchart of the chemical process from xylose to FOL was designed, which can realize the regeneration of biomass resources (xylose derived from corncob), the reuse and recycling of catalysts and solvents, and minimize the amount of solvents and pollutant emissions. [ABSTRACT FROM AUTHOR]