Atomically-ordered active sites in NiMo intermetallic compound toward low-pressure hydrodeoxygenation of furfural

Activation of oxygen-containing functional groups plays a key role in sustainable biomass upgrading and conversion. In this work, a NiMo intermetallic compound (IMC) catalyst was prepared based on layered double hydroxides (LDHs) precursors, which displayed prominent catalytic performance for furfural hydrodeoxygenation (HDO) to 2-methylfuran (2-MF) (yield: 99 %) at a rather low hydrogen pressure (0.1 MPa), significantly superior to NiMo alloy, monometallic Ni and other Ni-based catalysts ever reported. CO-IR, STEM, EXAFS and XANES give direct evidences that the atomically-ordered Ni/Mo sites in NiMo IMC determine the uniform bridging-type adsorption mode of C = O bond in furfural whilst adsorption of furan ring is extremely suppressed. In situ FT-IR and DFT calculation further substantiate that ordered Ni-Mo bimetallic sites of IMC, in contrast to the random atomic sequence in NiMo alloy, facilitate the activation and cleavage of C-OH bond in the intermediate (furfuryl alcohol, FOL), accounting for the production of 2-MF. This work demonstrates the decisive effect of atomically-ordered active sites in IMC catalyst on activation of oxygen-containing functional groups and product selectivity, which can be extended to catalytic upgrading of biomass-derived platform molecules.

Automated summary

This study demonstrates the superior catalytic performance of a NiMo intermetallic compound (IMC) catalyst in furfural hydrodeoxygenation (HDO) to 2-methylfuran (2-MF), highlighting the decisive effect of atomically-ordered active sites on activation of oxygen-containing functional groups and product selectivity. The ordered Ni-Mo bimetallic sites in IMC facilitate the activation and cleavage of C-OH bonds in intermediates, leading to enhanced production of 2-MF, which can potentially be extended to catalytic upgrading of biomass-derived platform molecules.