Selective Catalysis for Room-Temperature Hydrogenation of Biomass-Derived Compounds over Supported NiPd Catalysts in Water

Abstract

Utilizing biomass-derived furan-based platform chemicals for the production of a wide range of value-added components for application as fuels/fuel blenders and other fine chemicals is gaining much attention. Here, we demonstrated an efficient room-temperature selective hydrogenation of furan-based long chain aldol compounds over supported NiPd/SiO2, NiPd/RHA (RHA is rice-husk ash), and NiPd/Z4A (Z4A is zeolite 4A) catalysts in water. A wide range of furan-based compounds, such as 1,5-bis(furan-2-yl)penta-1,4-dien-3-one (1), 4-(furan-2-yl)but-3-en-2-one (3), 1,3-bis(furan-2-yl)prop-2-en-1-one (4), 1-(furan-2-yl)-3-(5-methylfuran-2-yl)prop-2-en-1-one (5), and 3-(furan-2-ylmethylene)pentane-2,4-dione (6), were conveniently hydrogenated to the corresponding saturated ketone products using the present protocol. Our findings inferred that the studied supported NiPd catalysts selectively promoted the hydrogenation of the C═C bond over the C═O bond to yield the corresponding saturated ketone products. The observed tuned catalytic properties can be attributed to the crucial role of the support in controlling the substrate-to-surface interactions, presumably, by disfavoring the interaction of polar carbonyl functional groups with the catalyst surface and, hence, facilitating the hydrogenation of C═C over C═O bonds. Moreover, the support RHA facilitated the high dispersion of NiPd nanoparticles (∼4 nm) for the NiPd/RHA catalyst. Hence, the NiPd/RHA catalyst displayed high stability under the catalytic reaction conditions and was reused for six consecutive catalytic runs without any significant loss in the catalytic activity.