Selective Hydrogenation of Biomass-Based 5-Hydroxymethylfurfural over Catalyst of Palladium Immobilized on Amine-Functionalized Metal–Organic Frameworks

Abstract

A catalyst of palladium [Pd/MIL-101(Al)-NH 2 ] supported on amine-functionalized MetalOrganic Frameworks (MOFs) allows selective hydrogenation of biomass-based 5-hydroxymethylfurfural (HMF) to 2,5-dihydroxymethyl-tetrahydrofuran (DHMTHF) with 2,5-dihydroxymethylfuran (DHMF) as an observed "intermediate". The Pd/MIL-101(Al)-NH 2 was prepared by using a direct anionic exchange approach and subsequent gentle reduction. The presence of free amine moieties in the frameworks of MIL-101(Al)-NH 2 is suggested to play a key role on the formation of uniform and well-dispersed palladium nanoparticles on the support. The adsorption experiments reveal that the amine-functionalized MOF supports show preferential adsorption to hydrogenation intermediate DHMF than in the case of reactant HMF owing to an enhanced hydrophilic nature of DHMF as well as improved hydrogen bonding interactions between DHMF and the MOF support, which promotes a further hydrogenation of DHMF to DHMTHF upon the in situ formation of DHMF over Pd/MIL-101(Al)-NH 2 . Moreover, our results also indicate that the observed high selectivity towards DHMTHF form HMF is closely related to the cooperation between metallic site and free amine moiety on the MOF support. Under the optimal conditions, a maximum DHMTHF yield of 96% with a full conversion of HMF is obtained by using Pd/MIL-101(Al)-NH 2 (Pd 3.0 wt%) catalyst at a low reaction temperature of 30 °C in aqueous medium. The research thus highlights new perspectives for aluminum-based and amine-functionalized MOF material for biomass transformation.

Immobilization of phosphotungstic acid in an amino‐containing metal–organic framework for oxidative desulfurization

“…The XRD patterns of PTA/NH 2 ‐MOF(Al) indicate that the immobilization of PTA has affected the phase of NH 2 ‐MIL‐101(Al) (Figs (d) and (e)). The peaks at 8.8°, 10.3°, 15° and 17.6° indicate that the pattern corresponds to the reported NH 2 ‐MIL‐53(Al) . The reason is that NH 2 ‐MIL‐101(Al) is transformed to NH 2 ‐MIL‐53(Al) during the loading process, when it is immersed in HCl aqueous solution for 10 h (Fig.…”

Metal Catalysts for the Efficient Transformation of Biomass‐derived HMF and Furfural to Value Added Chemicals

“…Furthermore at 16 MPa CO 2 pressure, along with the bottom phase having substrate‐catalyst/water, a large part was occupied by the upper phase CO 2 ‐H 2 , which facilitated the complete hydrogenation of DMF to DMTHF. Moreover, hydrogenation of HMF to 2,5‐di(hydroxymethyl)tetrahydrofuran (DHMTF) was also reported over Pd nanoparticles supported on amine functionalized metal‐organic frameworks (MOF), Pd/MIL‐101(Al)‐NH 2 ), at 30 °C using 1 MPa H 2 , where DHMF was observed as a reaction intermediate . Amine functionalized MOF showed a favourable adsorption for hydrogenated intermediate DHMF as compare to HMF because of the more hydrophilic nature and hydrogen bonding interaction with DHMF (Figure ) that led to a feasible hydrogenation of DHMF to DHMTHF over Pd/MIL‐101(Al)‐NH 2 .…”

“…Pd catalysts also displayed high catalytic performance towards the hydrogenation and hydrodeoxygenation of HMF . In this direction, Pd‐cesium dodeca‐tungstophosphoric acid supported over K‐10 acidic clay, Pd‐Cs 2.5 H 0.5 PW 12 O 40 /K‐10, catalyzed efficient hydrogenation/hydrogenolysis of HMF to 2,5‐dimethylfuran (DMF) in THF .…”

Studies of synergy between metal–support interfaces and selective hydrogenation of HMF to DMF in water

“…With the recent boom in transportation sectors, biomass-based biofuels are viewed as potential participants, as they provide a renewable carbon source for transportation fuels and chemicals [8]. In this respect, 5-(hydroxymethyl) furfural (HMF) obtained from the dehydration of sugars is an excellent platform for biobased fuels [9][10][11].…”