Hydrogenation Of HMF Research Articles

Critical Factors Affecting the Selective Transformation of 5-Hydroxymethylfurfural to 3-Hydroxymethylcyclopentanone Over Ni Catalysts.

The ring-rearrangement of 5-hydroxymethylfurfural (HMF) to 3-hydroxymethylcyclopentanone (HCPN) was investigated over Ni catalysts supported on different carbon supports and metallic oxides with different structure and acid-base properties. Their catalytic performance was tested in a batch stirred reactor in aqueous solution at 180 °C and 30 bar of H2. Under these conditions, the HMF hydrogenation proceeds through three possible competitive routes: (i) a non-water path leading to the total hydrogenation product, 2,5-di-hydroxymethyl-tetrahydrofuran (DHMTHF), and two parallel acid-catalyzed water-mediated routes responsible for (ii) ring-opening and (iii) ring-rearrangement reaction products. All catalyst systems primarily produced HCPN, but reaction rates and product distribution were influenced by several variables, some of them intensely analyzed in this work. The most proper conditions resulted to be the presence of the medium/strong Lewis's acidity of a Ni/ZrO2 catalyst (initial TOF=5.99 min-1 and 73 % HCPN selectivity) or the Brønsted acidity originated by an oxidized high surface area graphite, Ni/HSAG-ox (initial TOF=5.92 min-1 and 87 % HCPN selectivity). However, too high density of acidic sites on the catalyst support (Ni/Al2O3) and sulfur impurities from the HMF feedstock led to catalyst deactivation by coke deposition and Ni poisoning, respectively.

Deciphering in-situ surface reconstruction in two-dimensional CdPS3 nanosheets for efficient biomass hydrogenation

Steering on the intrinsic active site of an electrode material is essential for efficient electrochemical biomass upgrading to valuable chemicals with high selectivity. Herein, we show that an in-situ surface reconstruction of a two-dimensional layered CdPS3 nanosheet electrocatalyst, triggered by electrolyte, facilitates efficient 5-hydroxymethylfurfural (HMF) hydrogenation to 2,5-bis(hydroxymethyl)furan (BHMF) under ambient condition. The in-situ Raman spectroscopy and comprehensive post-mortem catalyst characterizations evidence the construction of a surface-bounded CdS layer on CdPS3 to form CdPS3/CdS heterostructure. This electrocatalyst demonstrates promising catalytic activity, achieving a Faradaic efficiency for BHMF reaching 91.3 ± 2.3 % and a yield of 4.96 ± 0.16 mg/h at − 0.7 V versus reversible hydrogen electrode. Density functional theory calculations reveal that the in-situ generated CdPS3/CdS interface plays a pivotal role in optimizing the adsorption of HMF* and H* intermediate, thus facilitating the HMF hydrogenation process. Furthermore, the reconstructed CdPS3/CdS heterostructure cathode, when coupled with MnCo2O4.5 anode, enables simultaneous BHMF and formate synthesis from HMF and glycerol substrates with high efficiency.

Regulating the oxidation state of Pd to enhance the selective hydrogenation for 5-hydroxymethylfurfural

The highly selective hydrogenation of 5-hydroxymethylfurfural to 2,5-dihydroxymethylfuran is an important reaction in the field of biomass hydrogenation, because it is a bridge between biomass resources and chemical industry. Here, we precisely constructed carbon nitride supported Pd-based catalysts by a simple impregnation-reduction method. By changing the reduction temperature, catalysts with different oxidation state could be precisely constructed. Moreover, the important correlation between the ratio of Pd0/Pd2+ and catalytic activity is revealed during the selective hydrogenation of HMF. The Pd/g–C3N4–300 catalyst with a Pd0/Pd2+ ratio of 3/2 showed the highest catalytic activity, which could get 96.9% 5-hydroxymethylfurfural conversion and 90.3% 2,5-dihydroxymethylfuran selectivity. Further density functional theory calculation revealed that the synergistic effect between Pd0 and Pd2+ in Pd/g–C3N4–300 system could boost the adsorption of the substrate and the dissociation of hydrogen. In this work, we highlight the important correlation between metal oxidation state and catalytic activity, which provides valuable insights for the rational design of precious metal catalysts for hydrogenation reactions.

One-step reductive amination of 5-hydroxymethylfurfural to 2,5-bis(aminomethyl)furan over a core–shell structured catalyst

2,5-Bis(aminomethyl)furan (BAF) is a diamine that is expected to have extensive applications in organic synthesis, medicine and polymer materials such as polyamides and polyimides. BAF can be prepared by one-step reductive amination of 5-hydroxymethylfurfural (HMF), one of the platform compounds for the added-valueconversion of biomass. Due to its complex structure, the one-step catalytically reductive amination of HMF to BAF in high yield is still a challenging issue. Herein, a core–shell structured catalyst (Ni@SiO2–0.2) was developed for this reaction, and the yield of BAF reached up to 99 % with aqueous ammonia as both ammonia source and solvent due to an isolation effect of the SiO2 shell. The isolation effect can prevent direct hydrogenation of HMF and self-coupling of BAF, thereby enhancing the selectivity of the reductive amination of HMF to BAF. In addition, the textural structure, acidity and acidic sites of the SiO2 shell can be tuned by adjusting the amount of TEOS during the catalyst preparation process, thus optimizing the performance of the catalyst. The characterization results also revealed that the Ni nanoparticles in the catalyst are uniformly dispersed and encapsulated within the SiO2 shell, which can decrease the charge density on the Ni surface and enhance the adsorption of ammonia and intermediates on the Ni surface, thus enhancing the catalytic activity of the catalyst.

2-Methylimidazole-modulated 2D Cu metal-organic framework for 5-hydroxymethylfurfural hydrodeoxygenation.

Preparation of the high value-added chemical 2,5-dimethylfuran (2,5-DMF) from the biomass-derived platform molecule 5-hydroxymethylfurfural (HMF) is of great significance in the preparation of biofuels. Here, a bottom-up strategy was used to prepare a metal-organic framework (MOF) material with a two-dimensional nanosheet morphology, named CPM, in which an additive 2-methylimidazole was introduced into the hydrothermal process of Cu2+ ions and terephthalic acid. Subsequently, CPM-700 prepared by heat treatment under an inert atmosphere showed excellent catalytic performance in the reaction of HMF hydrodeoxygenation to 2,5-DMF. The materials before and after pyrogenation were characterized by PXRD, XPS, TEM, N2 adsorption and desorption and so on. It was confirmed that compared with the catalyst derived from the cubic MOF material self-assembled by Cu2+ and terephthalic acid, the morphology of 2D nanosheets was beneficial for the reaction of HMF to 2,5-DMF. Combined with the experimental data, the possible reaction path of 2,5-DMF preparation from HMF is that 2,5-dihydroxymethylfuran was formed by hydrogenation of the aldehyde group on the furan ring, and then 2,5-DMF was obtained by hydrogenolysis. This paper provides an effective route for 2D MOF-derived catalytic materials in the selective hydrogenation of HMF.

Self-Reconstruction of Sulfate-Terminated Copper Oxide Nanorods for Efficient and Stable 5-Hydroxymethylfurfural Electrooxidation.

The electrochemical 5-hydroxymethylfurfural oxidation reaction (HMFOR) has been regarded as a viable alternative to sustainable biomass valorization. However, the transformation of the catalysts under harsh electrooxidation conditions remains controversial. Herein, we confirm the self-construction of cuprous sulfide nanosheets (Cu2S NSs) into sulfate-terminated copper oxide nanorods (CuO-SO42- NRs) during the first-cycle of the HMFOR, which achieves a near-quantitative synthesis of 2,5-furandicarboxylic acid (FDCA) with a >99.9% yield and faradaic efficiency without deactivation in 15 successive cycles. Electrochemical impedance spectroscopies confirm that the surface SO42- effectively reduces the onset potential for HMFOR, while in situ Raman spectroscopies identify a reversible transformation from CuII-O to CuIII-OOH in HMFOR. Furthermore, density functional theory calculations reveal that the surface SO42- weakens the Cu-OH bonds in CuOOH to promote the rate-determining step of its coupling with the C atom in HMF-H* resulting from HMF hydrogenation, which synergistically enhances the catalytic activity of CuO-SO42- NRs toward HMF-to-FDCA conversion.

Advances in Selective Hydrogenation of 5-Hydroxymethylfurfural over Heterogeneous Metal Catalysts

Biomass is an excellent renewable organic energy in nature. 5-hydroxymethylfurfural (HMF) is a significant platform chemical derived from biomass. It can be obtained from biomass and has the potential to produce high value-added derivatives. For the past few years, the chemocatalysis pathway has been extensively studied and is the main pathway of HMF transformation. In this paper, the influence factors and reaction mechanisms of different catalyst types on HMF hydrogenation processes were discussed. The latest progress on the efficient catalytic system using hydrogen, alcohol and other hydrogen sources to catalyze HMF was introduced. Future research prospects of catalytic hydrogenation of HMF were also prospected.

Selective electrocatalytic hydrogenation of lignocellulose-derived 5-hydroxymethylfurfural with superior productivities

Recently, valorization of biomass to value-added chemicals has drawn increasing attention due to carbonneutrality and sustainability. 5-Hydroxymethylfurfural is an important lignocellulose-derived biomass molecule. Herein, we have demonstrated the efficient electrocatalytic hydrogenation of 5-hydroxymethylfurfural to value-added 2,5-bis(hydroxymethyl)furan. An optimized electrolyzer with a highly electrolyte-permeable Pd cathode well balanced the selectivity, faradaic efficiency, and productivity. We have achieved high selectivity (97%) and faradaic efficiency (72%) at 50 mA cm-2 current density, and a record high productivity of 0.923mmol cm-2·h-1 at 100 mA cm-2 current density, ∼2 times advanced compared with the best productivity in prior reports. We applied in situ infrared reflection-absorption spectroscopy to investigate the electrode-potential-dependent reaction pathways and mechanism, confirming that the highly selective hydrogenation of HMF is due to the tilted adsorption geometry through carbonyl group bonding to the surface of electrode. This work offers an opportunity for the sustainable electrocatalytic valorization of renewable lignocellulose-derived biomass with superior productivities approaching industrial level.

Phase-Controlled Cobalt Catalyst Boosting Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran.

The search for non-noble metal catalysts for chemical transformations is of paramount importance. In this study, an efficient non-noble metal catalyst for hydrogenation, hexagonal close-packed cobalt (HCP-Co), was synthesized through a simple one-step reduction of β-Co(OH)2 nanosheets via a temperature-induced phase transition. The obtained HCP-Co exhibited several-times-higher catalytic efficiency than its face-centered cubic cobalt (FCC-Co) counterpart in the hydrogenation of the C=C/C=O group, especially for the 5-hydroxymethylfurfural (HMF) hydrogenation (8.5-fold enhancement). Density functional theory calculations demonstrated that HMF molecules were adsorbed more firmly on the (112_0) facet of HCP-Co than that on the (111) facet of FCC-Co, favoring the activation of the C=O group in the HMF molecule. The stronger adsorption on the (112_0) facet of HCP-Co also led to lower activation energy than that on the (111) facet of FCC-Co, thereby resulting in high activity and selectivity. Moreover, HCP-Co exhibited outstanding catalytic stability during the hydrogenation of HMF. These results highlight the possibility of fabricating hydrogenation catalysts with satisfactory catalytic properties by precisely tuning their active crystal phase.

On-Demand, Highly Tunable, and Selective 5-Hydroxymethylfurfural Hydrogenation to Furan Diols Enabled by Ni and Ni3Ga Alloy Catalysts

Catalytic conversion of the biobased platform chemical 5-hydroxymethylfurfural (HMF) into high-value-added products (e.g., diols) has attracted considerable attention, where controlling the products’ selectivity is a crucial and challenging issue. Herein, a series of hydrotalcite-based Ni and Ni3Ga alloy catalysts were prepared for HMF hydrogenation into furan diols. By optimizing the loaded metal and reduction temperature, >99% BHMTHF and 95.6% BHMF yields were gained over Ni1.5Al-LDO-700 and Ni1.5GaAl-LDO-700, respectively, under mild conditions. Characterizations and DFT calculations showed that the doped Ga resulted in charge transfer from Ga to Ni and disrupted the Ni arrangement, which weakened the furan ring adsorption and favored its tilted adsorption on the Ni3Ga alloy, consequently inhibited deep hydrogenation, and selectively produced BHMF. These catalysts were also versatile for hydrogenation of other furan aldehydes, achieving high selectivity toward un-/saturated alcohols on demand. This study provides an advanced strategy for the rational design of superior catalysts for tuning product selectivity on demand, with practical potential for upgrading biomass-derived platform molecules.

A Stable and Reusable Supported Copper Catalyst for the Selective Liquid-Phase Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Bis(hydroxymethyl)furan

Synthesis of 2,5-bis(hydroxymethyl)furan (BHMF) by selective 5-hydroxymethylfurfural (HMF) hydrogenation is ecofriendly and industrially important since HMF is obtained from renewable sources, and BHMF is a raw material used for production of biodegradable polymers. Four copper-based catalysts were prepared by incipient wetness impregnation (Cu/SiO2-I, Cu/Al2O3-I), precipitation–deposition (Cu/SiO2-PD) and coprecipitation (CuMgAl), and then tested in the liquid-phase hydrogenation of HMF. Metallic phases with large copper particles were obtained by incipient wetness impregnation, while precipitation methods gave highly dispersed metal copper nanoparticles. The pattern found for the concentration and strength of surface acid sites was: CuMgAl > Cu/Al2O3-I > Cu/SiO2-PD > Cu/SiO2-I. The copper-based catalysts active in HMF hydrogenation are all highly selective to BHMF, but the intrinsic activity and stability depend on metallic copper dispersion and support nature. The catalyst stability becomes poorer in the cases that the metallic phase is formed by large copper particles or interacts with high-acidity supports. Therefore, the catalyst with the highest activity, BHMF yield and stability was Cu/SiO2-PD. Furthermore, it was found that Cu/SiO2-PD is reusable in the selective liquid-phase HMF hydrogenation after being submitted to a two-step thermal treatment: (1) calcination under air flow at 673 K; (2) reduction under H2 flow at 523 K.

Paired electrocatalysis in 5-hydroxymethylfurfural valorization.

5-Hydroxymethylfurfural (HMF) has aroused considerable interest over the past years as an important biomass-derived platform molecule, yielding various value-added products. The conventional HMF conversion requires noble metal catalysts and harsh operating conditions. On the other hand, the electrocatalytic conversion of HMF has been considered as an environmentally benign alternative. However, its practical application is limited by low overall energy efficiency and incomplete conversion. Paired electrolysis and highly efficient electrocatalysts are two viable strategies to address these limitations. Herein, an overview of coupled electrocatalytic HMF hydrogenation or hydrogen evolution reaction (HER) with HMF oxidation as well as the associated electrocatalysts are reviewed and discussed. In this mini-review, a brief introduction of electrocatalytic HMF upgrading is given, followed by the recent advances and challenges of paired electrolysis with an emphasis on the integration HMF electrohydrogenation with HMF electrooxidation. Finally, a perspective for a future sustainable biomass upgrading community based on electrocatalysis is proposed.

Hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran via synergistic catalysis of Ni2In and acid-base sites

Conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to high-value-added chemicals is widely acknowledged as a flexible connection between biomass resources and chemical industries. Hydrogenation of HMF to 2,5-dimethylfuran (DMF) is denoted as environmentally sustainable but substantially challenging biomass utilization. Here, we reported an efficient and stable Ni2In/MgO-Al2O3 catalyst for the hydrogenation and hydrogenolysis of HMF to DMF. The Ni2In/MgO-Al2O3 catalyst delivered a 93.2 % DMF yield and exhibited excellent stability and reusability during the recycling test. Characterization and theoretical calculations reveal that the inactive indium geometrically isolates the active sites and modulates the electronic structure of Ni, leading to preferential CO hydrogenation and COH hydrogenolysis. Furthermore, acid-base sites and Ni2In in Ni2In/MgO-Al2O3 synergistically catalyze the hydrogenation-hydrogenolysis process of HMF to DMF. The Ni2In-acid-base sites synergistic catalysis mechanism provides a novel strategy for the rational design of efficient hydrogenation-hydrogenolysis catalysts.

Progress in Selective Conversion of 5‐Hydroxymethylfurfural to DHMF and DMF

DHMF and DMF are chemicals of high added value. This review summarized the recent developments on the conversion of HMF to DHMF and DMF according to catalytic system, including noble metal catalysts and non-noble metal catalysts.

Novel noble metal-free and recyclable Co-CoOx-FeNiCo/γ-Al2O3 catalyst for selective hydrogenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran or 2,5-Bis(hydroxymethyl)furan

The efficient production of the liquid fuel 2,5-dimethylfuran (DMF) from biomass-derived 5-hydroxymethylfurfural (HMF) is very complicated because of the presence of the aldehyde group, hydroxyl group, and CC bond. In this study, a novel Co-CoOx –FeNiCo/γ-Al2O3 catalyst was developed for selective hydrogenation of HMF to DMF. The catalyst was characterized by using XRD, TEM, SAED, BET, XPS, NH3-TPD, and H2-TPR techniques. The catalyst reduced at 500 °C exhibited excellent catalytic performance and the highest DMF yield (>99.9%) was obtained at 190 °C and 4 h. During the reaction, metal sites selectively hydrogenated the CO bond while acid sites (CoOx acid sites) selectively hydrogenolyzed CO bond. Appropriate surface acidity of the catalyst and the balance between metal and metal oxide species are the main factors for achieving a high yield of DMF. At reaction temperatures below 150 °C, DMF was not produced and HMF has completely converted into 2,5-Bis(hydroxymethyl)furan (BHMF), an important furan diol for polymers production. 100% BHMF yield was also obtained for the HMF hydrogenation over 300 °C reduced catalysts due to the high concentration of strong acid sites. The catalyst recyclability exhibited excellent stability and the original activity was maintained after six reuses. A reaction mechanism was also proposed.

A Light(er) Approach for the Selective Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Bis(hydroxymethyl)furan without External H2.

The selective conversion of 5-hydroxymethyfurfural (HMF), a biomass-derived platform molecule, to value added chemicals can ease the burden on petroleum-based fine chemical synthesis. The active contribution of renewable energy sources along with low cost, environmental friendliness, and a simple reaction system must be adopted for better sustainability. In this context, photocatalytic selective hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved over P25 titania nanoparticles without chemical squander. Simultaneously the photo-oxidation of p-methoxybenzyl alcohol (MeOBA) to p-methoxybenzaldehyde (MeOBaL), similar to biomass-derived vanillin, was carried out, abolishing the need of additional redox reagents. This system put forward the competent employment of photogenerated excitons for the valorization of lignocellulosic biomass to fine chemicals, which is an urgent requirement for sustainable chemical synthesis.

Integrated Cascade Process for the Catalytic Conversion of 5-Hydroxymethylfurfural to Furanic and TetrahydrofuranicDiethers as Potential Biofuels.

The depletion of fossil resources is driving the research towards alternative renewable ones. Under this perspective, 5‐hydroxymethylfurfural (HMF) represents a key molecule deriving from biomass characterized by remarkable potential as platform chemical. In this work, for the first time, the hydrogenation of HMF in ethanol was selectively addressed towards 2,5‐bis(hydroxymethyl)furan (BHMF) or 2,5‐bis(hydroxymethyl)tetrahydrofuran (BHMTHF) by properly tuning the reaction conditions in the presence of the same commercial catalyst (Ru/C), reaching the highest yields of 80 and 93 mol%, respectively. These diols represent not only interesting monomers but strategic precursors for two scarcely investigated ethoxylated biofuels, 2,5‐bis(ethoxymethyl)furan (BEMF) and 2,5‐bis(ethoxymethyl)tetrahydrofuran (BEMTHF). Therefore, the etherification with ethanol of pure BHMF and BHMTHF and of crude BHMF, as obtained from hydrogenation step, substrates scarcely investigated in the literature, was performed with several commercial heterogeneous acid catalysts. Among them, the zeolite HZSM‐5 (Si/Al=25) was the most promising system, achieving the highest BEMF yield of 74 mol%. In particular, for the first time, the synthesis of the fully hydrogenated diether BEMTHF was thoroughly studied, and a novel cascade process for the tailored conversion of HMF to the diethyl ethers BEMF and BEMTHF was proposed.

Cu-NPs@C Nanosheets Derived from a PVP-assisted 2D Cu-MOF with Renewable Ligand for High-Efficient Selective Hydrogenation of 5-Hydroxymethylfurfural.

5-Hydroxymethylfurfural (HMF) containing C=O, C-O, and furan ring functional groups is an important platform chemical derived from C6 sugars. The selective hydrogenation of C=O in HMF produces 2,5-dihydroxymethylfuran (DHMF), which is a potential sustainable substitute for petroleum-based building blocks. Here, 2,5-furandicarboxylic acid (H2 FDC), a promising sustainable alternative to terephthalic acid, was employed as a renewable ligand to synthesize a novel Cu metal-organic framework (Cu-FDC). With a polyvinyl pyrrolidone (PVP)-assisted approach, 2D Cu-FDC nano-lamellae of micrometer lateral dimensions and nanometer thickness could be obtained, which could be used as a precursor to fabricate 2D oxygen-rich carbon nanosheets embedded with Cu nanoparticles (denoted CFP-300) after a thermal treatment at 300 °C under N2 atmosphere. The synthesized CFP-300 exhibited excellent catalytic performance and stability for the selective hydrogenation of HMF to DHMF. These results demonstrated a sustainable route to synthesize efficient catalysts by employing metal-organic frameworks based on renewable ligands.

Cu-Co nanoparticles supported on nitrogen-doped carbon: An efficient catalyst for hydrogenation of 5-hydroxymethylfurfural into 2,5-bis(hydroxymethyl)furan

Production of the 2,5-Bis(hydroxymethyl)furan (BHMF) has important scientific value and strategic significance for the development of new biodegradable polyester materials. Herein, Cu-Co/NC composites containing bimetallic nanoparticles in nitrogen-doped carbon were produced by the calcination of zeolitic imidazolate frameworks (ZIFs). They featured a cubic Cu-Co core and a porous structure derived from the ZIFs. The surface morphology, surface area, and composition of the catalysts were analyzed by scanning electron microscopy (SEM), transmission electron microscope (TEM), thermogravimetric (TG) analysis, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), CO2-temperature program desorption (CO2-TPD), and N2 adsorption-desorption isotherms. A conversion of 93.7% of 5-hydroxymethylfurfural (HMF) with a BHMF selectivity of 92.4% was achieved using the Cu0.04Co1/NC-450 catalyst at a relatively low reaction temperature and H2 pressure. This outstanding catalytic performance was ascribed to the high dispersion of Co nanoparticles in the NC framework, forming Co-Nx species. We found that the synergistic catalysis of Cu-Co sites due to electron transfer contributed to the increase in the BHMF selectivity during HMF hydrogenation. The intensity of the XRD peaks corresponding to metallic Co decreased as the calcination temperature increases, which results in agglomeration of Co nanoparticles (NPs), and reduces the catalytic activity in HMF hydrogenation. Additionally, the conversion of HMF during hydrogenation remained stable after using Cu0.04Co1/NC-450 for ten cycles.

Solvent-mediated Zr-based coordination polymer with tunable acid properties for the dehydration of fructose and catalytic transfer hydrogenation of 5-hydroxymethylfurfural

In this work, a porous Zirconium based coordination polymer (Zr-ATMP) was facilely synthesized at room temperature with amino tris(methylene phosphonic acid) (ATMP) as ligand, and the surface acidic sites could be adjusted in different solvents. Specifically, the coordination polymer with equivalent content of Bronsted and Lewis acid sites was synthesized in aqueous system, showing high-efficiency catalytic activity for fructose dehydration to 5-hydroxymethylfurfural (HMF). In comparison, the coordination polymer containing an abundance of Lewis acid sites was synthesized in DMF solvent, which efficiently catalyzed the transfer hydrogenation of HMF. Compared to the catalysts preparation in organic solvents, the coordinatively unsaturated Zr4+ could be hydrated in water during catalyst preparation, resulting in the generation of additional Bronsted acid sites at the cost of Lewis acid sites. This contribution proposed a facile approach to prepare Zr-based coordination polymer with tunable acid properties for biomass valorization.