DMF Yield Research Articles

Optimization and Reaction Kinetics Studies on Copper-Cobalt Catalyzed Liquid Phase Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran

Abstract In the present work, hydrogenation of biomass derived 5-hydroxymethylfurfural (HMF) into fuel additive 2,5-dimethylfuran (DMF) is studied over Cu-Co/Al2O3 catalyst. The influence of various operating parameters such as temperature, pressure, catalyst amount, time and HMF concentration on the conversion HMF to DMF was optimized using well known Taguchi method as statistical tool. According to Taguchi method, under optimum reaction conditions viz. temperature 220 °C, pressure 30 bar, reaction time 6 h, catalyst loading 0.5 g, and HMF concentration of 0.2 wt%, maximum DMF yield (87 %) was recorded. Analysis of variance suggested that temperature and pressure are the most influencing factor. Mechanistic study suggested that DMF can be obtained via C = O hydrogenation over Cu metal due to preferential adsorption of HMF on Cu metal which further undergoes acid catalyzed hydrogenolysis and resulted DMF. The initial rates of reaction HMF to BHMF varied linearly with hydrogen pressure at different temperatures, catalysts loading, and reactant substrate concentration. These observations indicate first order kinetics for HMF disappearance. According to power-law model, the order with respect to HMF was found to be 0.9. The experimental data could also be explained using Langmuir-Hinshelwood kinetics. A competitive hydrogen with dissociative adsorption on catalysts surface and surface reaction as the rate-controlling step provided the best fit of the experimental data.

Hydrogenolysis of 5-Hydroxymethylfurfural To Produce 2,5-Dimethylfuran over ZrO2 Supported Cu and RuCu Catalysts

Glucose dehydration to HMF and its hydrogenolysis to DMF, a suitable biofuel, have been studied using the same catalysts for both processes. The 10CuZr catalyst shows the highest HMF yield (25.6%) with an acceptable glucose conversion (75.8%) after 1.5 h on stream. By increasing the time on stream from 1.5 to 5.5 h the HMF yield (33.2%) and glucose conversion (94.5%) are improved. In the case of DMF production, the 15CuZr catalyst shows the highest DMF yield (30%). This behavior is notably improved when Ru is added to the 15CuZr catalyst, reaching a DMF yield of 45.6%. These activity results could be related to the higher amount of Cu0 species exposed on the catalyst surface and the increase of coke resistance. Finally, the 1Ru15CuZr catalyst is used in DMF production using glucose derived HMF as raw material, and a DMF yield and HMF conversion of 16.4% and 77.5% are achieved, respectively.

Selective Hydrodeoxygenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran over Ni Supported on Zirconium Phosphate Catalysts.

Crystal α-zirconium phosphate (α-ZrP) was prepared by a hydrothermal method and exfoliated into a layered structure by n-hexylamine (C6H13NH2). Ni-based catalyst (Ni/ZrP) was promoted by loading nickel on the layered α-ZrP via ion exchange. The catalyst was performed to catalyze hydrodeoxygenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF), and a 68.1% yield of DMF and 100% conversion of HMF were achieved at 240 °C, 5 MPa H2, and 20 h. The DMF yield can still retain 52.8% after five cycles. The characteristics of the catalyst were investigated via N2 adsorption–desorption, X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, pyridine-adsorbed Fourier transform infrared (FTIR) spectra, FTIR spectra, inductively coupled plasma mass spectrometry, and thermogravimetric analysis–mass spectrometry, as well as Raman spectroscopy. A pathway from HMF to DMF was found with MF as the intermediate product, and DMF production was preferable via the −CH2OH group hydrogenolysis of HMF over Lewis acidic sites of Ni/ZrP, which is caused by the zirconium vacant orbits.

Dandelion-like cobalt oxide microsphere-supported RuCo bimetallic catalyst for highly efficient hydrogenolysis of 5-hydroxymethylfurfural

Currently, renewable biomass-derived energy sources and related transformation technologies are attracting numerous attentions due to the rapid consumption of fossil fuels and resulting increasing environmental pollution. Herein, a new dandelion-like cobalt oxide (CoOx) microsphere-supported bimetallic RuCo catalyst was fabricated by a simple one-pot embedding method and employed for the 5-hydroxymethylfurfural (HMF) hydrogenolysis to produce liquid 2,5-dimethylfuran (DMF) biofuel. It was found that bimetallic RuCo nanoparticles (NPs) with the average size of about 2.5 nm could homogeneously disperse on flower-like CoOx microspheres possessing abundant surface defects (i.e. oxygen vacancies and Co2+ species) simultaneously constructed. As-fabricated RuCo/CoOx catalyst exhibited excellent catalytic performance in above reaction, along with a quite high DMF yield of 96.5% at a high HMF/Ru molar ratio of 252.7, which was corelated with the unique synergy between bimetallic RuCo NPs and abundant surface defects at the metal-support interface, as well as the enhanced hydrogen spillover effect and the dandelion-like superstructure of the catalyst. Additionally, the strong interactions between RuCo species and the CoOx matrix in the RuCo/CoOx significantly prevented RuCo NPs from migration, aggregation, and leaching during the reaction. The present findings offer a new approach for designing other highly efficient and stable bimetallic catalysts applied in a variety of heterogeneous catalytic systems.

Well-distributed cobalt-based catalysts derived from layered double hydroxides for efficient selective hydrogenation of 5-hydroxymethyfurfural to 2,5-methylfuran

The synthesis of 2,5-dimethylfuran (DMF) from 5-hydroxymethylfurfural (HMF) is a highly attractive route to a renewable fuel. Herein, we propose that non-noble Co-based catalysts derived from layered double hydroxides (LDHs) can efficiently convert HMF into 2,5-dimethylfuran (DMF). Homogeneous elemental distributions of the Co-containing LDH precursors facilitate good dispersion of Co and the metal oxide species and also strong interaction between them on the resulting catalyst, therefore exhibiting superior reactivity under mild condition. Through fine modulation of the metal nanostructure, a high DMF yield of 74.2% at a mild reaction temperature of 130 °C with 0.7 MPa H2 can be achieved. The well-distributed Co sites on the metal-support interface are deduced to be responsible for the efficient HMF and H2 activations. The Co-based catalysts present good active both on hydrogenation of CO and CO, which have great potential for biomass utilization.

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.

Graphitic Carbon Nitride (g‐C3N4)‐derived Fe‐N‐C Catalysts for Selective Hydrodeoxygenation of 5‐Hydroxymethylfurfural to 2,5‐Dimethylfuran

AbstractAs Fe is more abundant and economic than Cu and Ni, it is probably a more attractive non‐noble alternative to precious metals in biomass conversions, for which usually require promising catalysts for large‐scale production. In this work, economic and environmental benign heterogeneous iron catalysts prepared by simultaneous pyrolysis of graphitic carbon nitride and iron precursors on activated carbon, were demonstrated to be active for the hydrodeoxygenation of biomass‐derived 5‐hydroxymethylfurfural to 2,5‐dimethylfuran. The effect of pyrolysis temperature, support, iron content, the type of g‐C3N4 and iron precursor, and N/Fe ratio were explored thoroughly, and reaction parameters such reaction temperature and H2 pressure were also investigated. The highest DMF yield of 85.7 % was obtained at 240 °C for 3 h, which is comparable to that obtained over iron catalysts prepared from precious iron complexes. The investigation of reaction pathway showed that 5‐methylfurfural was the possible intermediate. The stability of as‐prepared Fe‐N‐C catalyst could be improved after treatment with aqueous HCl solution.

Inclusion of Zn into Metallic Ni Enables Selective and Effective Synthesis of 2,5-Dimethylfuran from Bioderived 5-Hydroxymethylfurfural

5-Hydroxymethylfurfural (HMF) is an important platform chemical derived from C6 sugars and cellulose. The formed 2,5-dimethylfuran (DMF) via hydrogenolysis of HMF was denoted as a promising and sustainable fuel candidate. The further improvement of DMF yield is the central premise of this work, which is based on the elucidation of the relationship between catalytic performance and active sites. Herein, a NiZn alloy catalyst was formed through Zn inclusion to Ni by controllable reduction of the NiZnAl hydrotalcite-derived NiO–ZnO–Al2O3 mixed oxide. The combination of temperature-programmed reduction (TPR), in situ X-ray diffraction (XRD), CO-adsorbed infrared spectroscopy (CO–IR), and X-ray photoelectron spectroscopy (XPS) revealed that the surface of the NiZn catalyst was composed of β1-NiZn while the bulk was composed of α-NiZn. Moreover, the surface Ni atoms were geometrically isolated by Zn atoms and modulated to be electron-rich. Finally, the rate of C═O/C—O hydrogenolysis over C═C/C—C hydrogenation f...

Ruthenium supported on CoFe layered double oxide for selective hydrogenation of 5-hydroxymethylfurfural

A catalyst of ruthenium supported on CoFe layered double oxide (CoFe-LDO) allows selective hydrogenation of biomass-based 5-hydroxymethylfurfural (HMF) to the high-quality liquid fuel 2, 5-dimethylfuran (DMF) in the presence of tetrahydrofuran (THF). Under the optimal conditions, Ru/CoFe-LDO was exhibited higher catalytic performance, yielding 98.2% DMF with 100% HMF conversion at a relatively mild reaction temperature of 180°C for 6h. The structure and composition of the support and catalyst were investigated through a series of characterized methods Influence of various reaction parameters, such as reaction temperature, solvent Ru content of the catalyst and calcinations temperature of carrier etc., were explored with respect to HMF conversion and DMF yield. Although Ru/CoFe-LDO had a little loss in the catalytic activity after three successive reaction runs, the activity could be easily recovered by heating and reducing with hydrazine hydrate. Moreover our results also showed the cooperation between the metallic Ru site and the CoFe-LDO further facilitates the process of HMF hydrogenation to DMF.

High-yield production of 2,5-dimethylfuran from 5-hydroxymethylfurfural over carbon supported Ni–Co bimetallic catalyst

The catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) has attracted extensive research interests because DMF can be used as potential and competitive renewable transportation fuel or additives. Here we report a non-noble bimetallic catalyst with improved activity for hydrogenation and hydrogenolysis by introducing active carbon as support into a nickel–cobalt catalyst. The characterizations of the catalyst indicate that the Ni and Co species are uniformly dispersed on the active carbon through the wetness impregnation method. The influences of reaction temperature and hydrogen pressure are systematically investigated and an excellent yield (up to 95%) of DMF can be obtained at relatively mild conditions, 130°C and 1MPa H2, over the carbon supported Ni–Co bimetallic catalyst. The high catalytic activity originates from the synergistic effect between Ni and CoOx species, the high BET surface area of the catalyst, and the uniform dispersion of Ni and Co species on the active carbon. The catalyst could be reused for 5 times without loss of activity in a batch reactor. Futhermore, the conversion of HMF to DMF on a fixed-bed reactor was also investigated and the 2%Ni–20%Co/C catalyst exhibited an excellent yield to DMF (>90%) for 71h time on stream, indicating the high activity and stability of the catalyst.

Catalytic transfer hydrogenation/hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran over Ni-Co/C catalyst

Catalytic transfer hydrogenation/hydrogenolysis of 5-hydroxymethylfurfural (HMF) to valuable chemicals, 2,5-dimethylfuran (DMF), is realized over a carbon supported nickel-cobalt catalyst with formic acid as hydrogen donor. The highest DMF yield, 90.0%, is achieved at 210°C under self-generated pressure. A reaction route involving 5-methylfurfural (5-MF) instead of 2,5-bis(hydromethyl)furan (BHMF) as an intermediate has been investigated, which is different from that when H2 is used as hydrogen source in previous reports. The influence of the amount of formic acid is investigated on the conversion of HMF and the yield of DMF. The effectiveness of this strategy has also been used for the conversion of furfural to 2-methylfuran, another valuable chemicals.

Efficient hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran over a cobalt and copper bimetallic catalyst on N-graphene-modified Al2O3

2,5-Dimethylfuran (DMF) is an important candidate for liquid fuels and can be produced from biomass derived 5-hydroxymethylfurfural (HMF). Efficient transformation of HMF to DMF has not been achieved over a non-noble catalyst under milder conditions. Herein, we developed a copper and cobalt bimetallic nanoparticle catalyst supported on N-graphene-modified Al2O3 (CuCo®/NGr/α-Al2O3). It was found that CuCo®/NGr/α-Al2O3 could catalyze the conversion of HMF to DMF effectively and the yield of DMF could reach 99%. The catalyst was completely not active for the hydrogenation of the CC bond in furan and thus no 2,5-bis(hydroxymethyl)tetrahydrofuran (DHTHF) and 2,5-dimethyltetrahydrofuran (DMTHF) were detected.

Efficient Preparation of Liquid Fuel 2,5-Dimethylfuran from Biomass-Derived 5-Hydroxymethylfurfural over Ru–NaY Catalyst

An efficient catalytic process for the selective conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to high quality liquid fuel 2,5-dimethylfuran (DMF) was achieved over Ru nanoparticles dispersed on NaY zeolite. The structural and morphological features of the catalysts were studied by using various physicochemical characterization techniques. HMF conversion of 100 mol % with 78 mol % DMF yield was achieved using 2 wt %Ru–NaY catalyst in a short duration of the reaction. This catalyst displayed excellent recyclability without any loss in activity when it was used for five times. The study clearly showed that well-dispersed Ru nanoparticles are highly active and selective for the conversion of HMF to DMF. The reaction pathway for the conversion of HMF to DMF was explored by monitoring the reaction intermediates at different stages and intervals of the reaction.

Production of 2,5-dimethylfuran from 5-hydroxymethylfurfural over reduced graphene oxides supported Pt catalyst under mild conditions

Reduced graphene oxides supported platinum (Pt/rGO) is extremely active and selective for the production of 2,5-dimethylfuran (DMF) via hydrogenation of 5-hydroxymethylfurfural (HMF) among a series of supported Pt catalysts under mild conditions. The influence of varied reaction parameters, such as solvent, reaction temperature, H2 pressure, and HMF concentration were investigated with respect to the conversion of HMF and the yield of DMF. It was found that the yield of DMF reached 73.2% with a 100% conversion of HMF at 120°C, 3.0MPa H2 and 2.0h.

Copper-zinc alloy nanopowder: a robust precious-metal-free catalyst for the conversion of 5-hydroxymethylfurfural.

Noble-metal-free copper-zinc nanoalloy (<150 nm) is found to be uniquely suited for the highly selective catalytic conversion of 5-hydroxymethylfurfural (HMF) to potential biofuels or chemical building blocks. Clean mixtures of 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF) with combined product yields up to 97 % were obtained at 200-220 °C using 20-30 bar H2 . It is also possible to convert 10 wt % HMF solutions in CPME, with an excellent DMF yield of 90 %. Milder temperatures favor selective (95 %) formation of 2,5-furandimethanol (FDM). The one-pot conversion of fructose to valuable furan-ethers was also explored. Recycling experiments for DMF production show remarkable catalyst stability. Transmission electron microscopy (TEM) characterization provides more insight into morphological changes of this intriguing class of materials during catalysis.

Catalytic production of 2,5-dimethylfuran from 5-hydroxymethylfurfural over Ni/Co3O4 catalyst

Ni/Co3O4, a non-precious metal catalyst was used for the first time in the catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). Under relatively mild conditions (130°C, 1.0MPa), as high as 76% yield of DMF was achieved. The addition of Ni not only prevented the formation of by-products, which happened due to the over-reduction of Co3O4 during hydrogenolysis, but also enhanced the reusability of Ni/Co3O4, and the catalyst could be reused for 6 times without loss of activity.

MCPBA-mediated conjugation of dibenzosuberenone and amines or carboxylic acids

One-pot synthesis of skeletons 4, 5, and 6 was performed with moderate to good yields in DMF by mCPBA (m-chloroperoxybenzoic acid)-mediated condensation of dibenzosuberenone 1 and different 1,2-diaminobenzenes 2 or carboxylic acids 3. The oxidant-mediated reaction conditions had been discussed. Furthermore, reaction of 1 and oxalic acid was investigated for the formation of bianthronyl 9.

Nickel–Tungsten Carbide Catalysts for the Production of 2,5‐Dimethylfuran from Biomass‐Derived Molecules

The development of new catalytic systems for the conversion of biomass-derived molecules into liquid fuels has attracted much attention. We propose a non-noble bimetallic catalyst based on nickel-tungsten carbide for the conversion of the platform molecules 5-(hydroxymethyl)furfural into the liquid-fuel molecule 2,5-dimethylfuran (DMF). Different catalysts, metal ratios and reaction conditions have been tested and give rise to a 96% yield of DMF. The catalysts have been characterized and are discussed. The reaction mechanism is also explored through capture of reaction intermediates. The analysis of the reaction mixture over different catalysts is presented and helps to understand the role of nickel and tungsten carbide during the reaction.

Selective Transformation of 5-Hydroxymethylfurfural into the Liquid Fuel 2,5-Dimethylfuran over Carbon-Supported Ruthenium

A simple and efficient process was presented for the selective hydrogenation of 5-hydroxymethylfurfural (HMF) into the high-quality liquid fuel 2,5-dimethylfuran (DMF) in the presence of tetrahydrofuran (THF). Among the employed metal catalysts, the relatively inexpensive carbon-supported ruthenium (Ru/C) displayed the highest catalytic performance, which led to 94.7% DMF yield with 100% HMF conversion at a relatively mild reaction temperature of 200 °C for only 2 h. Although Ru/C had a little loss in the catalytic activity when it was used for five successive reaction runs, the partially deactivated Ru/C could be easily regenerated by heating at a mixed flow of H2 and N2. Moreover, the plausible mechanism involving an aldehyde group, a hydroxyl group, and a furan ring for the selective hydrogenation of HMF into DMF was also proposed. Subsequently, DMF was separated from the crude hydrogenation mixture according to their various boiling points by the combination of atmospheric distillation and vacuum distillation, and then, the chemical structures and physical properties of the separated DMF were confirmed to be consistent with the authentic DMF. More gratifyingly, Ru/C and THF were also found to be a good combination for the direct hydrogenation of carbohydrate-derived HMF into DMF, which is very important for the practical production of DMF from a variety of biomass-derived carbohydrates such as fructose, glucose, sucrose, maltose, cellobiose, starch, and cellulose.

Hydrogenation of 5-hydroxymethylfurfural in supercritical carbon dioxide–water: a tunable approach to dimethylfuran selectivity

The use of supercritical carbon dioxide–water on the hydrogenation of 5-hydroxymethylfurfural (HMF) was investigated over a Pd/C catalyst. It was possible to achieve a very high yield (100%) of DMF within the reaction time of 2 hours at 80 °C. A significant effect of CO2 pressure was observed on the product distribution. Simply by tuning the CO2 pressure it was possible to achieve various key compound, such as tetrahydro-5-methyl-2-furanmethanol (MTHFM) (<10 MPa), 2,5-dimethylfuran (DMF) (10 MPa) and 2,5-dimethyltetrahydrofuran (DMTHF) (>10 MPa) with very high selectivity. Optimization of other reaction parameters revealed that H2 pressure, temperature, as well as the CO2–water mole ratio, played an important role in the selectivity to the targeted DMF. It is interesting to note that a very high yield of DMF was achieved when a combination of CO2 and water was used. For instance, in the absence of water or CO2, the selectivity of DMF was low; similarly, an excess of water against the fixed pressure of CO2 reduced the selectivity to DMF. Hence, an optimized amount of water was mandatory in the presence of CO2 for the formation of DMF with high selectivity. This method was successfully extended to the hydrogenation of furfural, which could afford 100% selectivity to 2-methylfuran with complete conversion within a very short reaction time of 10 min. The studied catalyst could be recycled successfully without significant loss of catalytic activity.