Hydrogenation Of HMF Research Articles

Cu1–Cu0 bicomponent CuNPs@ZIF-8 for highly selective hydrogenation of biomass derived 5-hydroxymethylfurfural

Cu1–Cu0 bicomponent CuNPs@ZIF-8 is a highly selective and active catalyst for the hydrogenation of HMF to DHMF.

Carbonate-Catalyzed Room-Temperature Selective Reduction of Biomass-Derived 5-Hydroxymethylfurfural into 2,5-Bis(hydroxymethyl)furan

Catalytic reduction of 5-hydroxymethylfurfural (HMF), deemed as one of the key bio-based platform compounds, is a very promising pathway for the upgrading of biomass to biofuels and value-added chemicals. Conventional hydrogenation of HMF is mainly conducted over precious metal catalysts with high-pressure hydrogen. Here, a highly active, sustainable, and facile catalytic system composed of K2CO3, Ph2SiH2, and bio-based solvent 2-methyltetrahydrofuran (MTHF) was developed to be efficient for the reduction of HMF. At a low temperature of 25 °C, HMF could be completely converted to 2,5-bis(hydroxymethyl)furan (BHMF) in a good yield of 94% after 2 h. Moreover, a plausible reaction mechanism was speculated, where siloxane in situ formed via hydrosilylation was found to be the key species responsible for the high reactivity.

Selective hydrodeoxygenation of biomass derived 5-hydroxymethylfurfural over silica supported iridium catalysts

Catalytic performance of iridium supported on SiO2 was investigated for 5-hydroxymethylfurfural (HMF) transformation. Ir/SiO2 catalysts exhibiting different metal loading (1, 3, and 5 wt.%) were tested in the preliminary experiments in the hydrogenation of two probe molecules, e.g. ethyl pyruvate (EP) and ketopantolactone (KP) to evaluate the Ir dispersion on the catalyst activity in CO hydrogenation. In the transformation of HMF the influence of metal dispersion, iridium precursor and addition of H2SO4 were studied revealing that 2,5-bis-(hydroxymethyl)furan (BHMF) was the main product with 83% selectivity at 70% conversion of HMF over chlorine free Ir/SiO2 together with H2SO4 at 333 K in THF under 10 bar H2 pressure. On the other hand, one-pot synthesis of HMF to 2,5-dimethylfuran (DMF) was promoted in the presence of chlorine containing 1%Ir/SiO2(Cl) and H2SO4. Both of these products are considered high value-added chemicals from biomass-derived 5-hydroxymethylfurfural. The exposed iridium atoms together with the total acid sites are an important catalytic descriptor for hydrogenation of HMF to BHMF.

Ruthenium on Carbonaceous Materials for the Selective Hydrogenation of HMF.

We report the use of Ru catalysts supported in the activated carbon (AC) and carbon nanofibers (CNFs) for the selective production of liquid fuel dimethylfuran (DMF) and fuel additives alkoxymethyl furfurals (AMF). Parameters such as the reaction temperature and hydrogen pressure were firstly investigated in order to optimise the synthesis of the desired products. Simply by using a different support, the selectivity of the reaction drastically changed. DMF was produced with AC as support, while a high amount of AMF was produced when CNFs were employed. Moreover, the reusability of the catalysts was tested and deactivation phenomena were identified and properly addressed. Further studies need to be performed in order to optimise the stability of the catalysts.

Efficient Synthesis of Biomass‐Derived N‐Substituted 2‐Hydroxymethyl‐5‐Methyl‐Pyrroles in Two Steps from 5‐Hydroxymethylfurfural

An efficient two‐step synthesis for the conversion of biomass‐derived 5‐hydroxymethyl‐furfural (HMF) to a variety of N‐substituted 2‐hydroxymethyl‐5‐methylpyrroles was developed. In the first step, 1‐hydroxyhexane‐2,5‐dione (HHD) was obtained by hydrogenation of HMF and thereafter used in a Paal–Knorr reaction with a range of amines in the absence of catalyst at room temperature. The reaction could potentially be used as a click reaction.

Selective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran over Co3O4 catalyst by controlled reduction

Abstract 2,5-dimethyfuran (DMF), which is produced from 5-hydroxymethyfurfural (HMF) by hydrodeoxygenation (HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Selective hydrogenation of HMF into liquid fuel DMF has been widely researched. In this paper, Co3O4 catalyst was prepared by co-precipitation and was reduced at different temperatures to form Co–CoOx catalysts. The characterization of catalysts was tested by XRD, TEM, XPS, TPR, BET and NH3-TPD. Co–CoOx possessed a high amount of Co metal and CoOx acidic sites, wherein Co worked as the active hydrogenation sites and CoOx acted as the acid promoter to facilitate the selective HDO of HMF to DMF. The synergistic effect of Co–CoOx is the key for HDO of HMF, obtaining 83.3% of DMF yield at 170 °C, 12 h and the reduction temperature of 400 °C. This method not only saves the catalyst cost, but also promotes the utilization of biomass energy.

Homogeneous catalysed hydrogenation of HMF

Homogeneous Ru-catalyzed hydrogenation of HMF delivers a high percentage of trans-THFDM rather than only cis-THFDM known from heterogeneous hydrogenation.

Selective transformation of biomass-derived 5-hydroxymethylfurfural into 2,5-dihydroxymethylfuran via catalytic transfer hydrogenation over magnetic zirconium hydroxides

An economical and effective approach for the selective transformation of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF) was developed by catalytic transfer hydrogenation over various magnetic zirconium hydroxides (MZHs). As expected, MZH with a moderate Zr/Fe molar ratio of 2 displayed the highest catalytic activity, resulting in 98.4% HMF conversion and 89.6% DHMF yield at 150 °C for 5 h in the presence of 2-butanol that simultaneously acted as the hydrogen donor and reaction solvent, which was ascribed to its appropriate specific surface area, pore size and acid-base content. Moreover, a plausible reaction mechanism for the catalytic transfer hydrogenation of HMF into DHMF over MHZ(Zr/Fe=2) was also proposed, in which the basic hydroxyl groups with the aid of acidic zirconium metal centers were considered to be responsible for the pivotal hydride transfer via a six-membered ring structure.

Experimental and kinetic analysis of the liquid phase hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran over carbon-supported nickel catalysts

2,5-Dimethylfuran (DMF) is an attractive biofuel being stable, insoluble in water and an alternative to gasoline. DMF is accessible via hydrodeoxygenation of the cellulosic bio-based platform chemical 5-hydroxymethylfurfural (HMF). Efficient transformations of HMF to DMF have been reported to date; however, the kinetics of the reaction and a comprehensive analysis of the reaction network have not been addressed yet. In the present work, a plausible reaction network based on kinetic study of the hydrodeoxygenation of HMF over a carbon-supported nickel catalyst is proposed. The study of the reaction network showed the reaction indeed proceeds via the hydrogenation of the aldehyde group of HMF to form 2,5-bishydroxymethylfuran (BHMF) and subsequent conversion of BHMF to 5-methylfurfurylalcohol (MFA) followed by hydrogenolysis of MFA to DMF. Side reactions include the formation of 2,5-dihydroxymethyltetrahydrofuran (DHMTHF) and 2,5-dimethyltetrahydrofuran (DMTHF). A suitable kinetic model enabled estimating the kinetic parameters in the reaction temperatures range of 150–190°C. Kinetics analysis revealed the hydrogenation of HMF to BHMF as rate-determining step, while subsequent deoxygenation to DMF proceeds faster. Interestingly, most undesired reactions were kinetically hindered under selected reaction conditions allowing high selectivity to the target product DMF.

Selective hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran on Ru–MoOx/C catalysts

Synergetic effect and electronic transfer were investigated for the hydrogenation of HMF to DMF on Ru–MoOx/C catalyst.

Impact of Support Oxide Acidity in Pt-Catalyzed HMF Hydrogenation in Alcoholic Medium

Silica and three mixed silica oxides (silica–alumina, silica–niobia, and silica–zirconia) with nominally 5 wt% of the added element (Al, Nb and Zr) were prepared and used as supports for dispersing monometallic Pt-nanoparticles. The presence of the second oxide component on the silica surface influenced some properties of the final samples, like surface area and acidity. The samples acidity was measured in a recirculation adsorption line with 2-phenylethylamine probe, by performing the titrations both in cyclohexane and in methanol to gather the intrinsic and effective acidity, respectively. The acid site density of silica–alumina was the highest compared with the other oxides; in general, an important decrease of acid sites density was determined in methanol. The order of the effective acidity in methanol was different from that determined in cyclohexane only for silica–zirconia and silica–niobia, confirming the peculiar acidity of Nb-oxide compounds in polar liquids: Colloidal spherical platinum nanoparticles were synthesized and then deposited (1 wt%) on the oxide supports. The obtained metallic nanophases were studied in the reduction of 5-hydroxymethylfurfural (HMF) to valuable chemicals such as dimethylfuran, dimethyltetrahydro-furan, 2-hexanol. In particular, this study focused on the impact of the acidity of the oxide supports on reaction selectivity when 2-butanol is used as solvent. When Pt is not present, Nb-doped silica is the most effective catalyst to di-hydroxymethyl furan diether (DHMFDE) derived from Meerwein–Ponndorf–Verley reaction, maintaining its Lewis character also in protic medium. In the presence of Pt, Nb-doped silica, however, presents the higher selectivity to hydrogenolysis products, 5-methyl furan (5-MF).

Synergism studies on alumina-supported copper-nickel catalysts towards furfural and 5-hydroxymethylfurfural hydrogenation

The structure of alumina-supported copper-nickel catalysts prepared by impregnation method was studied by using a combination of various characterization techniques including XRD, N2-sorption, TEM, H2-TPR, NH3-TPD, XANES/EXAFS and CHNS methods. A series of characterizations revealed that dispersion of copper increases with an increase in nickel loading on ɣ-Al2O3 due to strong interaction between nickel and copper oxide particles. This also led to the formation of mixed copper-nickel oxides in calcined catalysts at the highest loading of nickel and copper (i.e. Cu/Ni=1). In catalytic activity, both the monometallic Cu/ɣ-Al2O3 and Ni/ɣ-Al2O3 showed lower activity and selectivity towards hydrogenation of both Furfural and 5-Hydroxymethylfurfural to 2-methylfuran (2-MF) and 2, 5-dimethylfuran (DMF), respectively. However, with increase in nickel loading, the activity and the selectivity of Cu/ɣ-Al2O3 drastically increased for both the cases and Cu-Ni/ɣ-Al2O3 (Cu/Ni=1) showed the highest catalytic activity. Furthermore, combination of Cu/Ni ratios and temperature plays a significant role in the product distribution, as in the case of furfural hydrogenation, at a lower temperature, furfuryl alcohol (FOL) appears as the main product while at a higher temperature, 2-methylfuran (2-MF) is found to be the dominant product over Cu-Ni/ɣ-Al2O3 (Cu/Ni=1) catalysts. Similarly, 2,5-bishydroxymethylfuran (BHF) is found to be the major product at a lower temperature and 2,5-dimethylfuran (DMF) is selectively produced at a higher temperature in the HMF hydrogenation. Furthermore, reaction pathways are discussed for both the reactions.

One‐Pot Deoxygenation of Fructose to Furfuryl Alcohol by Sequential Dehydration and Decarbonylation

AbstractFructose was deoxygenated to furfuryl alcohol (FFA) by tandem dehydration and decarbonylation in one pot over the AlCl3⋅6 H2O/Pd(OAc)2 catalyst combination to give a high FFA yield of 40.6 %. AlCl3⋅6 H2O behaves as an effective Lewis acid to catalyze the dehydration of fructose to 5‐hydroxymethylfurfural (HMF), and subsequently, Pd(OAc)2 catalyzes the removal of a CO moiety from HMF to produce FFA selectively. The hydroxyl group on the HMF intermediate was stabilized by poly(1‐vinyl‐2‐pyrrolidinone) through an intermolecular hydrogen bond, which accelerated the dehydration of fructose and inhibited the hydrogenation of HMF by formic acid. The decarbonylation of HMF was promoted and the unwanted decomposition of fructose was inhibited through the use of 4 Å molecular sieves. This research highlights a “one‐pot” catalytic system to transform renewable carbohydrates into fine chemicals by tandem dehydration and decarbonylation reactions without the separation or purification of HMF.

Rational design of Ni-based catalysts derived from hydrotalcite for selective hydrogenation of 5-hydroxymethylfurfural

A hydrotalcite-derived Ni-Al2O3 catalyst can catalyze HMF hydrogenation to DMF, DMTHF and DHMTHF with high yields (91.5%, 97.4% and 96.2% respectively).

Palladium/Carbon dioxide cooperative catalysis for the production of diketone derivatives from carbohydrates.

The one-pot production of industrially valuable diketone derivatives from carbohydrates is achieved through a bifunctional catalytic process. In particular, Pd/C-catalyzed hydrogenation of HMF in water and under CO2 affords 1-hydroxypentane-2,5-dione with up to 77% yield. The process is also eligible starting from fructose and inulin, affording 1-hydroxyhexane-2,5-dione with 36% and 15% yield, respectively. The key of the process is reversible in situ formation of carbonic acid, which is capable of assisting Pd/C during the hydrogenation reaction by promoting the dehydration of carbohydrates and the ring-opening of furanic intermediates. Interestingly, by changing the reaction medium from H2 O to a H2 O/THF mixture (1:9), it is possible to switch the selectivity of the reaction and to produce 2,5-hexanadione with 83% yield. Within the framework of sustainable chemistry, reactions presented in this report show 100% carbon economy, involve CO2 to generate acidity, require water as a solvent, and are conducted under rather low hydrogen pressures (10 bar).

Biomass into chemicals: One-pot production of furan-based diols from carbohydrates via tandem reactions

In this work, the direct production of furan-based diols from carbohydrates and their upstream raw materials via one-pot tandem reactions in ionic liquid/water system is presented. In this novel reaction system, ionic liquid serves as an advantageous solvent for polysaccharide (cellulose, inulin, sucrose) hydrolysis and hexose dehydration reactions, and heterogeneous Pd, Pt, Ir, Ni, Ru-based catalysts catalyze HMF hydrogenation reaction under relatively mild condition (50°C, 6MPa H2) to afford moderate to high yield (34.0–89.3%) of furan-based diols, namely, 2,5-dihydroxymethylfuran (DHMF) and 2,5-dihydroxymethyltetrahydrofuran (DHMTF). Our results show that the metal species strongly affects the selectivity of the products, while the nature of the support influences the activity of the catalysts significantly. By selecting the proper metal species and the support, controllable production of DHMF or DHMTF was realized. Based on the intermediates identified and the conversion results, the proposed reaction pathway, including possible side reactions were presented. Taken together, our catalytic system featured with simple process, mild condition, high yield of diols and adjustable product selectivity. The direct conversion of the carbohydrates and the upstream materials drives our technology nearer to real application for cost-efficient production of chemicals from biomass.

Selective hydrogenation of 5-hydroxymethylfurfural to 2,5-bis-(hydroxymethyl)furan using Pt/MCM-41 in an aqueous medium: a simple approach

An effective method was developed to obtain a very high yield of BHMF (98%) via hydrogenation of HMF in water.

Substrate and product role in the Shvo's catalyzed selective hydrogenation of the platform bio-based chemical 5-hydroxymethylfurfural.

The bio-based substrate and target product 2,5-bishydroxymethylfuran (BHMF) demonstrated to influence the reaction kinetics in the homogeneous reduction of 5-hydroxymethylfurfural (HMF) catalyzed by the Ru-based Shvo's catalyst. A combined experimental and computational study supports an important role of the -CH2OH moiety which may be involved in the catalytic cycle toward the formation of different intermediates from HMF and BHMF. The reaction is selective and leads to quantitative formation of BHMF working under mild conditions. Furthermore, an optimized recycling procedure which avoids the use of water, allows recover and reuse of the catalyst without loss of activity. The mechanistic insights from this work may be extended to provide a general description of the chemistry of the Shvo's catalyst feeding further bio-based molecules.

Efficient Production of Furan Derivatives from a Sugar Mixture by Catalytic Process

We present here the results of an investigation aimed at identifying catalysts for the dehydration of glucose and xylose to 5-hydroxymethylfurfural (HMF) and furfural in a diphasic reaction system, and the subsequent conversion of HMF and furfural to 2,5-dimethylfuran (DMF) and 2-methyl furan (MF) was also investigated. For the dehydration of glucose and xylose mixture, a series of SO42–/ZrO2–TiO2 solid acid catalysts were prepared by precipitation and impregnation method. Effects of various reaction parameters and catalyst reuse cycle toward the reaction performance were studied. Experimental results indicated that the product yield could reach 30.9 mol % (for HMF) and 54.3 mol % (for furfural) under the optimal experimental conditions. The SO42–/ZrO2–TiO2 catalyst is recoverable from the resulting product mixture and reused multiple times after calcination without any substantial change on the HMF and furfural yield. Furthermore, effects of various hydrogenation parameters of HMF and furfural in n-butanol promoted by carbon-supported ruthenium (Ru/C) were discussed, and the highest yield could reach 60.3 mol % (for DMF) and 61.9 mol % (for MF) under the optimal experimental conditions by starting with HMF and furfural in pure n-butanol, but the target products of DMF and MF could not be detected when directly used by the separated organic phase as solvent and substrate. However, the DMF and MF yield could reach 32.7 and 17.5 mol %, respectively, when the separated organic phase undergoes a further purification, which indicated that the purification of the organic phase is a key step for the further hydrogenation of HMF and furfural to DMF and MF.

A two-step approach for the catalytic conversion of glucose to 2,5-dimethylfuran in ionic liquids

Lignocellulosic biomass is an attractive resource for producing transportation fuels, and consequently novel approaches are being sought for transforming the lignin and cellulosic constituents of biomass to fuels or fuel additives. Glucose, the monomer of cellulose, is a good starting material for exploring such chemistries. We report here the results of an investigation aimed at identifying catalysts for the dehydration of glucose to 5-hydroxymethylfurfural (HMF) dissolved in ionic liquids and the subsequent conversion of HMF to 2,5-dimethylfuran (DMF), a high-energy content product that could be used as a fuel or fuel additive. Heteropoly acids were found to be exceptionally active and selective catalysts for the dehydration of glucose. Nearly 100% yield of HMF could be achieved using 12-molybdophosphoric acid (12-MPA) in a solution of 1-ethyl-3-methylimidazolium chloride (EMIMCl) and acetonitrile. The addition of acetonitrile to EMIMCl suppressed the formation of humins from glucose. The high HMF selectivity achievable with heteropoly acid catalysts is ascribed to stabilization of 1,2-enediol and other intermediates involved in the dehydration of glucose and the avoidance of forming the 2,3-enediol intermediate leading to furylhydroxymethyl ketone (FHMK). Carbon-supported metals, and in particular Pd/C, were effective in promoting the hydrogenation of HMF dissolved in EMIMCl and acetonitrile to DMF. The following intermediates were observed in the hydrogenation of HMF to DMF: 5-methylfurfural (MF), 5-methylfurfyl alcohol (MFA), and 2,5-dihydroxymethylfuran (DHMF). The relative rate of formation and consumption of these compounds was explored by using each of them as a reactant in order to identify the reaction pathway from HMF to DMF. It was also observed that HMF produced via glucose dehydration could be converted to DMF without isolation, if the dehydration catalyst, 12 MPA, was replaced by the hydrogenation catalyst, Pd/C. This two-step catalytic approach provides the basis for completely converting glucose to HMF and further converting HMF to DMF.