Hydrogen-transfer conversion of furfural into levulinate esters as potential biofuel feedstock

Furfural is directly converted to levulinate esters（isopropyl levulinate and furan-2-ylmethyl-levulinate） as potential biofuel feedstocks, through a combined catalytic strategy. Nb;O;-ZrO;mixed oxide microspheres are used as bifunctional catalysts for hydrogen-transfer hydrogenation and acid-catalyzed alcoholysis in isopropanol. Bifunctional catalysts improve sustainability of furfural conversion through process intensification. Hydrogen transfer hydrogenation from isopropanol avoids dangerous hydrogen gas, and abates process and environmental costs. Isopropyl levulinate and furan-2-ylmethyl-levulinate are the main products that can be applied as blending components in biodiesel or hydrocarbon fuels.

Crystal-phase engineering of PdCu nanoalloys facilitates selective hydrodeoxygenation at room temperature

Selective hydrodeoxygenation of biomass-derived aromatic alcohols to value-added chemical or fuel is of great importance for sustainable biomass upgrading,and hydrodeoxygenation of 5-hydroxymethylfurfural(HMF)to 2,5-dimethylfuran(DMF)is one of the most attractive reactions.Achieving the conversion of HMF to DMF using H_(2)at ambient temperature is challenging.In this work,we used PdCu nanoalloys to catalyze the selective hydrodeoxygenation reaction of HMF to DMF using H_(2)as the reducing agent.The reaction path and the product selectivity are governed by the crystallographic phase of the PdCu nanoalloys.It was discovered that body-centered cubic(BCC)PdCu nanoalloys supported on activated carbon(AC)exhibited outstanding performance with 93.6%yield of DMF at room temperature(PdCu/AC-BCC).A combination of experimental and density functional theory(DFT)studies showed that the tilted adsorption modes of furanic intermediates on PdCu-BCC nanoalloy surfaces accounted for the high selectivity of DMF;however,furan ring was activated on PdCu face-centered cubic(FCC)nanoalloy surfaces.Furthermore,PdCu/AC-BCC could also catalyze the hydrodeoxygenation of other aromatic alcohols at room temperature while maintaining the aromatic structures.This work opens the way for selective hydrodeoxygenation of the aromatic alcohols at room temperature with the aromatic ring intact.