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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]

The transformation of lignocellulosic biomass to platform compounds (γ-valerolactone, GVL) was a significant component in biomass development. Herein, sulfonated Zr-based metal-organic frameworks (MOF-808), a bifunctional heterogeneous catalyst with Lewis and Bronsted acid sites, were prepared to catalyze the one-pot cascade reaction of furfural (FUR) to GVL. The successful modification of the sulfonic group on MOF-808 was substantiated by multiple characterization methods. By adjusting the sulfuric acid concentration to balance the Lewis acid and Bronsted acid sites of the catalyst, S-808–2.37 was confirmed as the preferred catalyst and a 60.4 % GVL yield was achieved with 99.1 % carbon balance under the optimal conditions. Moreover, the 72.8 % GVL yield reached in the 40x magnification experiment also boded well for the catalyst's application potential. The work in this paper opened up new perspectives for the application of MOF-808 porous materials in the field of selective catalytic conversion of biomass involving multi-step reactions. [Display omitted] • Strong interaction between Zr and OH of H 3 BDC led to the formation of strong Lewis acidic/basic sites in the frameworks. • The cooperative role of strong Lewis acidic/basic sites in the S-808–2.37 contributed to the excellent catalytic performance. • This work provided a promising strategy to modulate the acid-base properties of MOF-808 without affecting its structure. [ABSTRACT FROM AUTHOR]