Hydrogenolysis Of 5-hydroxymethylfurfural Research Articles

Oxygen Vacancies Enrichment in Citric Acid-Assisted Synthesis of Zirconia Supported Ni Catalyst for Highly Selective Hydrogenolysis of 5-Hydroxymethylfurfural.

2, 5-Dimethylfuran (DMF), which is a promising new-generation liquid biofuel, has attracted widespread attention owing to the sustainability of biomass-derived energy sources. In this study, a highly dispersed zirconia-supported nickel catalyst (CA-Ni/ZrO2) was prepared via citric acid-assisted wetness impregnation for the selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) to produce DMF. The characterization results confirmed the presence of Zr3+ species in the mesoporous CA-Ni/ZrO2 catalyst and the formation of oxygen vacancies during its preparation, which led to the formation of a large number of catalytically active sites for the adsorption and activation of the C=O/C-O groups. Under appropriate reaction parameters, an excellent DMF selectivity of 99.1 % and an HMF conversion of 98.4 % were achieved. A suitable kinetic model revealed that DMF was preferentially formed via the 2,5-dihydroxymethylfuran intermediate route, although a 5-methylfurfural route was also observed. Additionally, the interaction between Ni and ZrO2 significantly affected the stability of the catalyst. This study will provide guidelines for optimizing the catalytic conversion of furan derivatives over heterogeneous catalysts.

Efficient hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran over Ni-C3N4 catalysts with ultra-low Ni loading

Selective hydrogenolysis of biomass-based platform compounds is of great importance for the production of chemicals and fuels. Herein, we reported that the catalyst of Ni-C3N4 supported on H2 activated carbon (HC) synthesized by a simple coordination-impregnation-pyrolysis method is efficient for the hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF); the yield of 94.2% can be obtained in a batch reactor and the lifetime of greater than 120 h can be achieved in fixed-bed experiment. It is demonstrated that Ni nanoparticles coated by graphitic C3N4 shell were highly dispersed on the surface of HC and the Ni loading is as low as 0.86 wt%, beneficial to the anti-sintering of Ni nanoparticles during the reaction. Both XPS characterizations and theoretical calculations reveal that Ni3N is the intrinsic active component for the hydrogenolysis, which exhibits efficient activity for the dissociation of C–O bond. This work opens up a new avenue to develop catalysts with single non-noble metal component for the efficient conversion of biomass-based chemicals.

Selective hydrogenation of 5-hydroxymethylfurfural triggered bya high Lewis acidic Ni-based transition metal carbide catalyst

The high-efficiency conversion of biomass resources to biofuels has attracted widespread attention, and the active sites and synergistic effect of catalysts significantly impact their surface arrangement and electronic structure. Here, a nickel-based transition metal carbide catalyst (Ni/TMC) with high Lewis acidity was prepared by self-assembly of transition metal carbide (TMC) and nickel, which exhibited excellent performance on synergistic hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural (HMF) into liquid biofuel 2,5-dimethylfuran (DMF). Notably, Ni/WC with the highest Lewis acidity (4728.3 μmol/g) can achieve 100% conversion of HMF to 97.6% yield of DMF, with a turn-over frequency of up to 46.5 h−1. The characterization results demonstrate that the rich Lewis acid sites yielded by the synergistic effect between Ni species and TMC are beneficial for the CO hydrogenation and C–O cleavage, thereby accelerating the process of hydrodeoxygenation (HDO). Besides, a kinetic model for the HDO of HMF to DMF process has been established based on the experimental results, which elucidated a significant correlation between the measured and the predicted data (R2 > 0.97). Corresponding to the adsorption configuration of Ni/WC and substrate determined by in-situ FTIR characterization, this study provides a novel insight into the selective conversion of HMF process for functional biofuel and bio-chemicals.

Regulation of Pt Loading on Co/Al2O3 Catalysts for Selective Hydrogenation and Hydrogenolysis of 5‐Hydroxymethylfurfural to 2,5‐Bis(hydroxymethyl)furan and 2,5‐Dimethylfuran

AbstractSelective hydrogenation and hydrogenolysis of 5‐hydroxymethylfurfural (HMF) to 2,5‐bis(hydroxymethyl)furan (BHMF) and 2,5‐dimethylfuran (DMF) were explored by regulating the nanosized Pt on Co/Al2O3 catalysts. Characterization results revealed that the catalyst acidity was influenced by adjusting the Co/Pt composition, while the addition of more Pt loading on Co/Al2O3 catalysts resulted in a facilitation of H2 reduction process. Lower size of catalyst particles was obtained for the Co−Pt system in comparison to the monometallic Co/Al2O3 catalyst. Additionally, the structural characterizations by XRD, XANES, and XPS established the co‐existences between metallic Pt0/Co0 and oxophilic PtO2/CoOx, acting as the active components for the reactions. Operated under a full HMF conversion, the Co1Pt0.050Al catalyst with high Pt loading gave >99.9 % BHMF selectivity at 40 °C; whereas, an 86.7 % of DMF selectivity was noticeable over low Pt loading of the Co1Pt0.013Al catalyst at 160 °C. This investigation evidenced that the selective production of BHMF or DMF towards hydro‐conversion of HMF was relied on the amount of Pt contents on Co/Al2O3 catalyst, in which the metal sizes and acidity had meaningful effects on the hydrogenation and hydrogenolysis processes.

Selective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran with high yield over bimetallic Ru-Co/AC catalysts.

Catalytic hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) has become a hot topic in the bioenergy field in recent years. It remains a challenge to mediate the activation/hydrogenation/hydrogenolysis of C-O and C[double bond, length as m-dash]O bonds of HMF at high temperatures. Herein, bimetallic Ru-Co/AC catalysts were prepared by the "two-step" reduction method and were used to catalyze the hydrogenolysis of HMF to DMF. The effects of different reduction methods, Ru/Co ratios, and Ru loading on the catalytic performances of the Ru-Co/AC catalysts were investigated, and the physicochemical properties of the catalysts were characterized by TEM, XPS, H2-TPR, etc. It was found that the catalysts reduced by the "two-step" reduction method exhibited better catalytic activities than those fabricated by a single H2 or NaBH4 reduction method. The introduction of Co metals promoted the dispersion of Ru nanoparticles (NPs) on AC and the transfer of electrons from Co to Ru, thereby improving the catalytic activity. An excellent yield of DMF up to 97.9% and 98.7% conversion of HMF were achieved in a short time (1.5 h) under the optimal conditions (200 °C, 1 MPa). Furthermore, the possible reaction pathway for the hydrogenolysis of HMF to DMF over 5%Ru-1%Co/AC catalyst is also discussed. The work shows that the Ru-Co/AC catalysts have great potentials for the conversion of HMF into liquid fuel DMF.

Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran Over a Modified CoAl-Hydrotalcite Catalyst.

The catalytic hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) is a promising route towards sustainable liquid fuels with a high energy density. Herein, a novel CuCoNiAl-containing mixed metal oxide catalyst (CuCoNiAl-MMO) was prepared by calcination a layered double hydroxide (LDH) precursor in N2 at 500 °C, then applied for the catalytic hydrogenolysis of HMF to DMF. The effects of reaction time, reaction temperature and hydrogen pressure on DMF selectivity were investigated. Under relatively mild reaction conditions (180°C, 1.0 MPa H2, 6.0 h), CuCoNiAl-MMO showed both a high initial activity and selectivity for hydrogenolysis of HMF to DMF, with HMF conversion rate of 99.8% and DMF selectivity of 95.3%. Catalysts characterization studies using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) revealed the presence of various metal oxides and metallic copper on the surface of the CuCoNiAl-MMO catalyst, with the presence of mixed metal-oxide-supported metallic Cu nanoparticles being responsible good hydrogenolysis activity of the catalyst for selective DMF synthesis.

Insights into the interfacial effects in Cu-Co/CeOx catalysts on hydrogenolysis of 5-hydroxymethylfurfural to biofuel 2,5-dimethylfuran

The interface site between metal and support possess unique electronic and morphological structure, providing distinct active centers for favorable reaction in catalytic conversion of biomass derivatives to valuable chemicals. In this study, a series of Cu-Co/CeOx catalysts were prepared for hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) via reduction of the corresponding layered double hydroxide precursors. The characterizations indicated the formation of CoCe-Vö interface (Vö denotes oxygen vacancy) and the effect of hydrogen spillover from Cu species to CoCe-Vö interface. Furthermore, the experiments and theoretical calculations verified that CoCe-Vö interface could activate the CO bond. The optimized catalyst showed a DMF yield of > 90% at 180 °C and 1.5 MPa H2 with no deactivation in the cycling tests. This study reveals the interfacial effects of the nanocatalysts, including the oxygen vacancies and hydrogen spillover, on hydrogenolysis of HMF, which provided a simple and efficient approach for synthesis of high-performance non-noble metal nanocatalysts applied to the hydrogenolysis of various biomass derivatives.

Selective 5-Hydroxymethylfurfural Hydrogenolysis to 2,5-Dimethylfuran over Bimetallic Pt-FeOx/AC Catalysts

The selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) platform molecule to 2,5-dimethylfuran (DMF) has attracted increasing attention due to its broad range of applications. However, HMF, with multiple functional groups, produces various byproducts, hindering its use on an industrial scale. Herein, a bimetallic Pt-FeOx/AC catalyst with low Pt and FeOx loadings for selective HMF hydrogenolysis to DMF was prepared by incipient wetness impregnation. The structures and properties of different catalysts were characterized by XRD, XPS, TEM, ICP-OES and Py-FTIR techniques. The addition of FeOx enhanced Pt dispersion and the Lewis acidic site density of the catalysts, and was found to be able to inhibit C=C hydrogenation, thereby im-proving DMF yield. Moreover, the presence of Pt promoted the reduction of iron oxide, creating a strong interaction between Pt and FeOx. This synergistic effect originated from the activation of the C–O bond over FeOx species followed by hydrogenolysis over the adjacent Pt, and played a critical role in hydrogenolysis of HMF to DMF, achieving a yield of 91% under optimal reaction conditions. However, the leaching of Fe species caused a metal–acid imbalance, which led to an increase in ring hydrogenation products.

Titanium silicalite-1 supported bimetallic catalysts for selective hydrogenolysis of 5-hydroxymethylfurfural to biofuel 2, 5-dimethylfuran

Production of biofuels from biomass resources has received wide attention because of the current energy crisis. Recently, significant interest has been directed towards the selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) to produce biofuel 2, 5-dimethylfuran (DMF). In this study, non-noble Ni–Cu catalysts with various Ni/Cu ratios, supported on titanium silicalite-1 (TS-1), were prepared through a solid-phase grinding method and used to catalyze the hydrogenolysis of HMF to DMF under a hydrogen atmosphere. The structure and surface morphology of the catalysts were characterized by X-ray diffraction, Fourier-transform infrared, thermogravimetry, X-ray photoelectron spectroscopy, temperature-programmed desorption of ammonia, scanning electron microscopy, and N2 adsorption-desorption techniques. Under the optimized reaction conditions, the conversion of HMF and the selectivity for DMF over a 40%Ni–5%Cu/TS-1 catalyst could reach 100.0% and 97.3%, respectively. Importantly, because the strong interaction of the Ni–Cu alloy structure prevents further reaction of the furan ring, almost no by-products are produced. The metal sites of Ni and Cu and the acid sites of TS-1 combine to provide a synergistic effect, which is beneficial to the hydrogenolysis of HMF. In addition, reusability experiments showed that the catalyst maintained good activity and stability.

Selective hydrogenolysis of 5-hydroxymethylfurfural to produce biofuel 2, 5-dimethylfuran over Ni/ZSM-5 catalysts

2, 5-Dimethylfuran (DMF), which is one of the most promising liquid biofuels, has received widely concern due to the development and utilization of biomass energy. In this work, Ni/ZSM-5 catalysts with different nickel content were prepared by a simple solid-phase grinding synthesis method and exhibited a significant activity for the selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) to produce DMF. The characterization of catalysts was tested by XRD, FT-IR, TG-DTG and N2 adsorption–desorption techniques. The effects of nickel loading ratios, reaction conditions and reaction mechanism were investigated. Under optimal experimental conditions, HMF conversion of 91.2% and DMF selectivity of 96.2% were obtained. It was found that a suitable proportion of metal sites and acidic sites on the catalyst surface were important for the selective hydrogenolysis, and 5-methylfurfural was detected as an important intermediate product in this reaction.

Insights into the Synergistic Effect in Pd Immobilized to MOF-Derived Co-CoOx@N-Doped Carbon for Efficient Selective Hydrogenolysis of 5-Hydroxylmethylfurfural

Co-CoOx-containing N-doped porous carbon-supported palladium catalysts were prepared via a ZIF precursor calcination and a simple impregnation route. The material was employed for the hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). The Co-CoOx-containing N-doped porous carbon provides a high dispersion and anchoring effect on active metal as well as abundant surface defects with strong adsorption ability to the oxygenated groups and enhanced electron transfer capability, which could promote the activation and H2 spillover and the cascade reaction of HMF hydrogenolysis to DMF. As-obtained palladium-based nanocatalysts exhibited excellent catalytic hydrogenolysis performance, and there is no apparent change in activity in six runs. The reasonable synergism between surface defects and active metallic species is the primary reason for such excellent catalytic effects. Most importantly, the strategy proposed enables us to adjust the physicochemical properties of the catalyst surface to design new bifunctional catalysts with significantly improved performance.

Selective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran catalyzed by ordered mesoporous alumina supported nickel-molybdenum sulfide catalysts

The efficient transformation of biomass resources to biofuels has attracted much attention. Herein, ordered mesoporous alumina supported nickel-molybdenum sulfide catalysts (denoted as Ni-MoS2/mAl2O3) were prepared by evaporation-induced self-assembly (EISA) method and used for the hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). Under mild conditions (130 °C, 1 MPa H2), the 5Ni-7MoS2/mAl2O3 catalyst achieved 95 % yield of DMF. The results of characterizations and DFT calculation showed that the active center was proposed to the coordinated unsaturated site (CUS) located at S-edge. And the intrinsic activity of CUS was directly related to the proportion of Mo substituted by Ni. The 5Ni-7MoS2/mAl2O3 catalyst containing CUS with high proportions of Ni replacing Mo showed higher TOF and lower apparent activated energy. Besides, 2-propanol can cooperate with molecular hydrogen to improve DMF yield by forming ethers that were easier to be hydrogenolyzed. The present findings provided a new catalytic system for converting HMF to DMF.

Highly active bifunctional Pd-Co9S8/S-CNT catalysts for selective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran

A series of Pd-Co bimetallic catalysts were smoothly synthesized using sulfur-modified carbon nanotubes (S-CNT) as support by impregnation method. Those catalysts were characterized by XRD, XPS, TEM, SEM, H2-TPR, TGA, and nitrogen adsorption-desorption. Selective catalytic hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) was realized over these synthesized sulfur-modified Pd-Co bimetallic supported on carbon nanotubes (PdCox/S-CNT) under mild conditions. Among them, PdCo8/S-CNT catalyst possessed extremely active and selective for the production of DMF, giving 96.0 % conversion of HMF with 83.7 % selectivity to DMF at the temperature of 120 °C with 0.3 MPa H2 for 13 h. It is found that the formed Co9S8 species are related to the high catalytic activity in PdCo8/S-CNT. Control experiments for evaluating the roles of palladium and Co9S8 revealed that Pd catalyzed the hydrogenation of the aldehyde group in HMF whereas Co9S8 was beneficial for hydrogenolysis of the hydroxy group in HMF. The remarkable hydrogenolysis/hydrogenation performance of the bifunctional Pd-Co9S8/S-CNT was due to support-enhanced adsorption effect and the effective synergy between highly dispersed metallic Pd and the Co9S8 nanoparticles.

Understanding catalytic hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) using carbon supported Ru catalysts

Herein, our study has demonstrated that microporous carbon supported Ru catalysts can selectively convert 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) in isopropanol through hydrogenolysis in a catalytic ratio of 2.47mol% under 5 bar of hydrogen at 125 °C for 1 h. DMF yield can reach 69.52% with complete HMF conversion. The effects of reaction temperature, hydrogen pressure, metal loading and reaction solvent for hydrogenolysis have been carefully investigated. In addition, to better understand the influence of the intrinsic nature of carbonaceous material, carbon materials possessing different surface texture including microporosity, mesoporosity and nonporous carbon black were used as catalyst supports, and structural properties have been comprehensively characterized by powder X-ray diffraction spectrometer (PXRD), transmission electron microscopy (TEM), nitrogen and CO2 sorption, thermogravimetric analysis (TGA), and X-ray absorption spectroscopy (XAS). We have concluded that the nature of the carbonaceous material affects the Ru nanoparticle formation upon thermal reduction. The atomic configuration of Ru nanoparticles on carbon support (i.e., metallic Ru or RuOx) would direct the catalytic pathway differently and could be attributed to the interaction between ruthenium and carbon surface.

Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran under Mild Conditions without Any Additive

The hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) is a very significant reaction, and it is a typical route for producing important chemicals from biomass. Efficient catalysts without any additive for the hydrogenolysis of HMF to DMF under mild conditions are highly desirable. Herein, we found that the Pd/C catalyst prepared in γ-valerolactone (Pd-GVL/C) is an efficient catalyst for the hydrogenolysis of HMF to DMF, and 95.6% of DMF could be obtained at 80 °C without any additive. The GVL interacted with Pd particles and enhanced the activity of the catalyst. It is the first example to achieve the hydrogenolysis of HMF to DMF below 100 °C without any additive.

Nanoporous Carbon: Liquid-Free Synthesis and Geometry-Dependent Catalytic Performance.

Nanostructured carbons with different pore geometries are prepared with a liquid-free nanocasting method. The method uses gases instead of liquid to disperse carbon precursors, leach templates, and remove impurities, minimizing synthetic procedures and the use of chemicals. The method is universal and demonstrated by the synthesis of 12 different porous carbons with various template sources. The effects of pore geometries in catalysis can be isolated and investigated. Two of the resulted materials with different pore geometries are studied as supports for Ru clusters in the hydrogenolysis of 5-hydroxymethylfurfural (HMF) and electrochemical hydrogen evolution (HER). The porous carbon-supported Ru catalysts outperform commercial ones in both reactions. It was found that Ru on bottleneck pore carbon shows a highest yield in hydrogenolysis of HMF to 2,5-dimethylfuran (DMF) due to a better confinement effect. A wide temperature operation window from 110 to 140 °C, with over 75% yield and 98% selectivity of DMF, has been achieved. Tubular pores enable fast charge transfer in electrochemical HER, requiring only 16 mV overpotential to reach current density of 10 mA·cm-2.