Nickel-Catalysed Vapour-Phase Hydrogenation of Furfural, Insights into Reactivity and Deactivation

Abstract

Furfural is a key bioderived platform molecule, and its hydrogenation affords access to a number of important chemical intermediates that can act as "drop-in" replacements to those derived from crude oil or novel alternatives with desirable properties. Here, the vapour phase hydrogenation of furfural to furfuryl alcohol at 180 °C over standard impregnated nickel catalysts is reported and contrasted with the same reaction over copper chromite. Whilst the selectivity to furfuryl alcohol of the unmodified nickel catalysts is much lower than for copper chromite as expected, the activity of the nickel catalysts in the vapour phase is significantly higher, and the deactivation profile remarkably similar. In the case of the supported nickel catalysts, possible contribution to the deactivation by acidic sites on the catalyst support is discounted based on the similarity of deactivation kinetics on Ni/SiO 2 with those seen for less acidic Ni/TiO 2 and Ni/CeO 2. Powder X-ray diffraction is used to exclude sintering as a primary deactivation pathway. Significant coking of the catalyst (~ 30 wt% over 16 h) is observed using temperature programmed oxidation. This, in combination with the solvent extraction analysis and infrared spectroscopy of the coked catalysts points to deactivation by polymeric condensation products of (reactant or) products and hydrocarbon like coke. These findings pave the way for targeted modification of nickel catalysts to use for this important biofeedstock-to-chemicals transformation.

Atom efficient PtCu bimetallic catalysts and ultra dilute alloys for the selective hydrogenation of furfural

“…[13,14] An array of alternative metal catalysts have been used in the literature for the hydrogenation of furfural to furfuryl alcohol in both the liquid and vapour phase, examples being: Cu, Ni, Pd, Pt, Co, Rh, Ir and Ru. [10,[15][16][17][18][19][20][21][22] Pt has been shown previously to be highly active and selective at low reaction temperatures under a headspace hydrogen atmosphere in the liquid phase. [16] Additionally, Pt is also effective for the hydrogenation of furfural in the vapour phase and also under Ultra-High Vacuum (UHV) conditions on Pt(111).…”

Total Hydrogenation of Furfural under Mild Conditions over a Durable Ni/TiO2–SiO2 Catalyst with Amorphous TiO2 Species

“…Another adverse effect of SiO 2 dissolution might be related to the coking effect since the Si–OH groups may contribute to the polymerization of FAL or FA under reaction conditions. Indeed, the TG analysis (Figure S6B) on the spent catalyst showed a remarkable weight loss (3.5 wt %) at a temperature from 200 to 500 °C, which was much less than that in an early report …”

“…Wei and co-workers found that high exposure of the Ni(111) plane in Ni/MMO-CO 3 promotes activated adsorption of both the furan ring and CO group and favors the production of a fully hydrogenated product. However, Ni catalysts always underwent deactivation with time on stream (TOS) either in the gas phase or in the liquid phase due to the coke formation by oligomerization and deoxygenation, regardless of the support categories (SiO 2 , TiO 2 , and CeO 2 ) . The authors proposed that tuning the selectivity of the nickel by expense of some of its high hydrogenation activity may be helpful for developing stable Ni catalysts .…”

“…However, Ni catalysts always underwent deactivation with time on stream (TOS) either in the gas phase or in the liquid phase due to the coke formation by oligomerization and deoxygenation, regardless of the support categories (SiO 2 , TiO 2 , and CeO 2 ) . The authors proposed that tuning the selectivity of the nickel by expense of some of its high hydrogenation activity may be helpful for developing stable Ni catalysts . We noticed that one of the commonly used supports to tune the electronic property of Ni is TiO 2 , which plays a dual role by activating the CO bond as well as stabilizing the metal nanoparticles via so-called strong-metal–support interaction (SMSI). , Stimulated by these studies, we herein reported the long period continuous hydrogenation of FAL over a TiO 2 –SiO 2 composite-supported Ni catalyst, which showed high stability and selectivity toward THFA within 120 h studied.…”

Synthesis and Characterization of Nickel(II) Homogeneous and Supported Complexes for the Hydrogenation of Furfural to Furfuryl Alcohol

“…Non-noble metal catalysts are a promising alternative if they exhibit the same or better activity and selectivity as their precious metal counterparts [13]. Kathryn and co-workers reported the application of a Ni/SiO 2 catalyst for the selective hydrogenation of FF to FA with a selectivity of 50% at a high reaction temperature of 180 • C [14]. In another example, a Ni/Al 2 O 3 catalyst displayed poor FA selectivity, giving methylfuran (MF), tetrahydrofurfuryl alcohol (THFA), tetrahydrofuran (THF), and furan (FU) [15].…”