Furfural Research Articles

Upgrading of lignocellulosic biomass-derived furfural: An efficient approach for the synthesis of bio-fuel intermediates over γ-alumina supported sodium aluminate

• A simple and green protocol for the aldol condensation of furfural with acetone was developed over γ-Al 2 O 3 supported sodium aluminate (SA) catalyst. • The SA/γ-Al 2 O 3 catalyst demonstrated the unprecedented catalytic activity (99.5% conversion with 90% selectivity) under mild conditions. • The distribution of active sites over the high surface area, amount of basic sites, and inherent mesoporosity are the contributing factors. • SA/γ-Al 2 O 3 surpassed the activity of state of the art materials reported for this transformation. • The correlation between catalyst properties and the catalytic activity was studied. The synthesis of value-added chemicals from simple molecules originating from biomass have been greatly acknowledged today. Herein, we report a sustainable protocol for the furfural (FUR) condensation with acetone (Ac) over γ-Al 2 O 3 supported sodium aluminate (SA) catalyst. The SA/γ-Al 2 O 3 catalysts are characterized with different techniques like TPD, XRD, TGA, BET, SEM, and FTIR analysis. The effect of SA loading, catalyst concentration, mole ratio, reaction time, and the reaction temperature on product distribution were investigated systematically. The 25wt.% SA/γ-Al 2 O 3 demonstrated the unprecedented conversion of FUR (99.5%) with 90% selectivity to 4-(2-Furyl)-3-buten-2-one (FAc) under mild reaction conditions. The catalyst surpassed the activity of state of the art materials reported for this transformation. The textural properties of SA/γ-Al 2 O 3 are in good correlation with the observed catalytic activity of the material. The significant catalytic activity is attributed to its inherent properties such as the active sites distribution over high specific surface area (SSA), amount of basic sites, and inherent mesoporosity. The catalytic activity of the 25SA/γ-Al 2 O 3 is compared with the various catalysts reported and is superior to the reported catalysts. On top of it, recycling experiments have proven that the catalyst is stable that can be used repeatedly with consistent catalytic activity.

Determination of Rate Equation for the Electrochemical Hydrogenation and Hydrogenolysis of Furfural in Acidic Media over Copper

The use of electricity from renewable sources allows for carbon neutral electrochemical processes to be operated. One example process is that of the electrochemical hydrogenation and hydrogenolysis of furfural (FF) to furfuryl alcohol (FA) and 2-methylfuran (MF). FA is used as a reactant in making furanic polymers for molds and castings, and MF has been identified as a high octane fuel. The electrochemical reactions of FF to FA and MF occur in parallel in acidic conditions on Cu catalysts. In this work we investigated the reaction mechanism by proposing a set of elementary steps, deriving the corresponding rate equation, and fitting it to the data. A Langmuirian trend was seen in the production rate vs FF concentration data.Experimentation was done using a catholyte that contained 0.1 or 0.5 M H2SO4 with a concentration of FF between 10 and 120 mM. The potential was first varied in pH 0 with 100 mM FF to determine the Tafel slope and exchange current densities, as well as the range of potential where the reaction is not mass transfer limited. The Tafel region of the system was found to be between -517 mV and -572 mV. To determine the effect of concentration of FF, the applied potential was set to -560 mV vs RHE, where the system is limited by kinetics and not mass transfer. The reaction rates to desired products were found to change from positive order to zero order with respect to FF concentration, showing a Langmuirian trend. It was found that the plateau in the reaction rate was 50% and 58% lower for MF and FA species respectively when the pH was changed from 0 to 1. The reaction rate equation was determined to be the equation that best fit the data across both pH levels.

Stability study of furans, glucose and xylose under overliming conditions: Effect of sugar degradation products

Abstract Detoxification with Ca(OH)2 has been proved as an effective method for detoxifying various lignocellulosic hydrolysates liquor. The present work aims to study the effect of overliming conditions on synthetic solutions including glucose, xylose, hydroxymethylfurfural (HMF), furfural (FF), and their various mixtures. Experimental design in line with chromatographic analysis was used to explain the influence of three main factors with distinct levels: pH, temperature, and detoxification time. Furans showed stability under all the studied conditions: pH (0.2; 4; 6; 10, and 12), temperature (25 and 60 °C), and detoxification time (15, 30, and 60 min) even after reflux. Xylose and glucose degradation was observed at pH 12 and followed the same pattern at various treatments. These findings are of great importance revealing the influence of sugar degradation products released at pH 12, with a maximum absorbance of 280 nm, and correlating them to furans loss.

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

Bio-based levulinic acid (LA), furfural (FF), and hydroxymethylfurfural (HMF) represent key chemical intermediates when biorefining biomass resources, i.e., either cellulose, glucose, hexoses, etc. (HMF/LA), or hemicellulose, xylose, and pentose (FF). Despite their importance, their online in situ detection by process analytical technologies (PATs), solubility, and its temperature dependence are seldom available. Herein, we report their solubility and temperature dependence by examining n-hexane, cyclohexane, benzene, toluene, 1,4-dioxane, diethyl ether, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, formic acid, n-butanol, n-propanol, ethanol, methanol, and water. These solvents were selected as they are the most common nonpolar, polar aprotic, and polar protic solvents. Fourier-transform infrared (FTIR) spectroscopy was applied as a fast, accurate, and sensitive method to the examined solutions or mixtures. The latter also enables operando monitoring of the investigated compounds in pressurized reactors. Selected temperatures investigated were chosen, as they are within typical operating ranges. The calculated thermodynamic data are vital for designing biorefinery process intensification, e.g., reaction yield optimization by selective compound extraction. In addition to extracting, upstream or downstream unit operations that can benefit from the results include dissolution, crystallization, and precipitation.

Morphology-dependent catalytic activity of tungsten trioxide (WO3) nanostructures for hydrogenation of furfural to furfuryl alcohol

The development of effective and low-cost catalysts for the hydrogenation and stabilization of bio-oils is still a challenge that needs to be overcome. Several nanostructured WO3 catalysts were synthesized in this study to investigate the effect of their morphology on their catalytic activity and selectivity for the hydrogenation of biomass-derived compounds such as furfural (FF). The morphology of the catalysts was tuned via a surfactant-assisted hydrothermal process. Nanorod and nanoprism WO3 catalysts were produced using dodecyl dimethylammonium bromide (DAB) and poly (ethylene-alt-maleic anhydride), respectively, while WO3 nanocubes were produced without the use of surfactants. Various analytical techniques were used to characterize the morphology of the synthesized WO3 catalyst. Furthermore, the hydrogenation of FF was used as a probe reaction to evaluate the catalytic performance of the WO3 nanostructures. Notably, DAB-assisted WO3 nanorods (D-WO3) exhibited a relatively high furfuryl alcohol (FFA) selectivity of 85% with an FF conversion of 52% at 100 °C, under 10 bar of H2 pressure over a reaction time of 120 min. A plausible route for the hydrogenation of FF into FFA and other products over D-WO3 nanocatalyst was illustrated. The D-OW3 nanocatalyst’s promising results indicate that it could be a viable, low-cost, and efficient alternative catalyst for hydrogenating FF into FFA.

Magnetic Fe3O4 nanoparticles and ZrO2-doped mesoporous MCM-41 as a monolithic multifunctional catalyst for γ-valerolactone production directly from furfural

A magnetically-recoverable multifunctional catalyst (Fe3O4/ZrO2@MCM-41) was tailored by the impregnation of ZrO2 supported on mesoporous MCM-41 coated Fe3O4 nanoparticles, which successfully served as a monolithic catalyst for the cascade conversion of furfural (FAL) giving high yield to γ-valerolactone (GVL), a versatile platform molecule. The ordered hexagonal framework of the parent MCM-41 well reserved after the embedding of Fe3O4 and ZrO2. The incorporation of Fe3O4 could not only impart the catalyst with a strong magnetism, but also tune its acidity to promote GVL production. An impressive yield of 85% was accomplished straight from FAL processing with iso-propanol as a hydrogen donor and solvent. The kinetic study demonstrated higher activation energy for levulinate-to-GVL step (86.9 kJ/mol) than FAL transfer hydrogenation (35.0 kJ/mol) and subsequent alcoholysis process (51.0 kJ/mol). The catalyst could be fully recovered by an external magnetic field and showed good reusability. The sustainability of this conversion represents greatly improved by the process intensification based on one-pot reaction, magnetically-recoverable multifunctional catalyst, and mild operating conditions without using gaseous hydrogen.

Domino transformation of furfural to γ-valerolactone over SAPO-34 zeolite supported zirconium phosphate catalysts with tunable Lewis and Brønsted acid sites

The economic and highly efficient synthesis of γ-valerolactone (GVL) is being increasingly focused due to its wide applications in solvent, chemical, and fuel. Herein, a range of SAPO-34 supported zirconium phosphate (ZPS-X) catalysts were prepared for a facile one-pot conversion of furfural (FF) to GVL through a series of cascaded reactions involving transfer hydrogenation, etherification, alcoholysis and esterification. The introduction of zirconium phosphate renders the formation of relatively strong Lewis acid sites, and the amount of Lewis (L) and Brønsted (B) acid sites of ZPS-X catalysts could be modified by adjusting the molar ratio of Zr to P (Zr/P ratio). Specifically, ZPS-1.0 having an appropriate Zr/P ratio with relatively strong L acid sites exhibited superior activity and selectivity for the production of GVL from FF.

Mechanism study on the formation of furfural during zinc chloride-catalyzed pyrolysis of xylose

Furfural (FF) is a promising platform compound that can be selectively produced by the fast pyrolysis of xylan-based biomass in the presence of zinc chloride (ZnCl2). Whereas, the catalytic effect of ZnCl2 and the FF formation mechanism remain uncovered. The present work aims to give a deep insight into the formation mechanism of FF under the catalysis of ZnCl2 by combining quantum chemistry calculations and fast pyrolysis experiments. Density functional theory (DFT) calculations and fast pyrolysis experiments were conducted with xylose as the model compound. ZnCl2 affects the pyrolysis reactions through the binding of Zn atom and O atom of xylose initially, with manifest electron exchange between Zn and O. The activation free energies of the pyrolysis reactions can be decreased when ZnCl2 stays at the reaction center of the transition states. Both ring-opening and 1,2-dehydration can be promoted by ZnCl2, whereas ring-contraction is hindered by ZnCl2 because ZnCl2 is away from the reaction center of the ring-contraction. Due to the distinct influence of ZnCl2 on different reactions, the rate-determining steps in some of the possible FF formation pathways are changed. Hence, the competitiveness of these pathways is altered to a great degree, which should be responsible for the selective production of FF. Xylose tends to generate FF through the acyclic d-xylose decomposition channel due to the catalysis of ZnCl2. The most favorable FF generation pathway involves the successive cyclization, 1,2-dehydration between 2-OH and 1-H, electrocyclic dehydration, and 1,2-dehydration between 4-OH and 5-H following the formation of a d-xylulose intermediate.

Biodegradation of furan aldehydes in lignocellulose hydrolysates

Lignocellulose is the most abundant renewable organic carbon resource on earth. However, due to its complex structure, it must undergo a series of pretreatment processes before it can be efficiently utilized by microorganisms. The pretreatment process inevitably generates typical inhibitors such as furan aldehydes that seriously hinder the growth of microorganisms and the subsequent fermentation process. It is an important research field for bio-refining to recognize and clarify the furan aldehydes metabolic pathway of microorganisms and further develop microbial strains with strong tolerance and transformation ability towards these inhibitors. This article reviews the sources of furan aldehyde inhibitors, the inhibition mechanism of furan aldehydes on microorganisms, the furan aldehydes degradation pathways in microorganisms, and particularly focuses on the research progress of using biotechnological strategies to degrade furan aldehyde inhibitors. The main technical methods include traditional adaptive evolution engineering and metabolic engineering, and the emerging microbial co-cultivation systems as well as functional materials assisted microorganisms to remove furan aldehydes.

Adsorption of organic compounds from aqueous solution by pyridine-2-carboxaldehyde grafted MIL-101(Cr)-NH2 metal-organic frameworks

Metal-organic frameworks (MOFs) are of particular interest in the adsorption of organic pollutants. This study investigated the adsorption of aniline (ANI), furfural (FUR), and bisphenol A (BPA) in aqueous solution using MIL-101(Cr)-X (X = –H, –NO2, –NH2 and, –N-2-pyc), MIL-100(Cr, Fe), HKUST-1, and ZIF-8. For the first time, an imino-functionalized MOF was used to adsorb organic compounds in water. MOFs were characterized by XRD, N2 adsorption-desorption, SEM, TEM, elemental analysis, and FTIR. MIL-101-N-2-pyc demonstrated the highest adsorption capacity of 460.8, 126.5, and 100.7 mg/g towards 500 mg/L BPA, ANI, and FUR respectively. The adsorption isotherms better suited the Langmuir model than the Freundlich model. Importantly, 98% of BPA (100 mg/L) was removed and the kinetic data correlated well with the pseudo-second-order model (R2 > 0.998). Binary adsorption of FUR and acetic acid (AA) were determined for industrial relevance. MIL-101-N-2-pyc outperformed commercial activated carbon and the other MIL-101s with an impressive co-adsorption of 66.1 mg/g FUR and 62.5 mg/g AA. Overall, the adsorption mechanism was due to hydrogen bonding, π-π interaction, and electrostatic attraction. Moreover, MIL-101-N-2-pyc exhibited remarkable structural stability and less than 0.01 wt% Cr leached into water. The adsorbent regeneration was improved after 4 cycles in methanol.

Selective Hydrogenation of Furfural over the Co-Based Catalyst: A Subtle Synergy with Ni and Zn Dopants.

A multimetal doping strategy has aroused extensive attention in promoting a non-noble catalyst for selective hydrogenation reaction. Herein, a multimetallic catalyst (NiCoZn@CN) with excellent catalytic performance for hydrogenation of furfural (FAL) to furfuryl alcohol (FOL) is prepared through a facile, inexpensive, and efficient pyrolysis method. Using H2 as a H donor, extremely high selectivity (>99%) with 100% conversion is attained over the optimal NiCoZn@CN-600 catalyst. The subtle synergy between Co and Ni, Zn dopants, which remarkably promotes the performance of the Co-based catalyst, is revealed. In the NiCoZn@CN system, Co0 is proven to be the main active site, whose content is greatly improved by Ni and Co dopants. Additionally, the Ni dopant could also benefit activation of H2 and the Zn dopant could enhance metal nanoparticle dispersion and the porous structure of the catalyst. In situ FTIR indicates that the vertical adsorption mode of FAL with the Oaldehyde terminal on NiCoZn@CN-600 ensures a selective hydrogenation process. With a N-doped carbon matrix, NiCoZn@CN-600 shows good cycling stability in five times run. NiCoZn@CN-600 is also competent in the catalytic transfer hydrogenation (CTH) of FOL, affording >99% yield with 2-propanol as a H donor. This study opens an avenue toward rational design of multimetallic doping catalysts with high selectivity for challenging reactions in the conversion of biomass-derived compounds.

A kinetic model of multi-step furfural hydrogenation over a Pd-TiO2 supported activated carbon catalyst

The multi-step, aqueous phase hydrogenation kinetics of furfural (FUR) to furfuryl alcohol (FA), 2-methylfuran (2MF), tetrahydrofurfuryl alcohol (THFA) and 5-hydroxy-2-pentanone (5H2P) over Pd-TiO2 on an activated carbon catalyst (derived from a monolith structure) was studied (180 °C, 2.1 MPa). Titanium addition created a metal–acid functional catalyst and promoted 5H2P synthesis from furfural. A Langmuir-Hinshelwood model with two active sites (a metal site for hydrogenation steps and an acid site for ring opening step) was applied to fit the kinetic data and parameters of the reaction system were obtained using non-linear regression of experimental data. The kinetic model showed an acceptable agreement with the experimental data with R2 of 0.93–0.96 and concentration residuals (experimental-model) typically ≤ 5%. Adsorption constants of 2MF and THFA were significantly lower than the adsorption constants of the other three compounds. A reaction rate constant of 1.6–1.8 mol/gcat.h for furfural consumption was predicted by the model. Reaction rates of 0.2–0.35 mol/gcat.h, 0.1–0.13 mol/gcat.h and 0.8–1.0 mol/gcat.h were predicted for formation of 2-methylfuran, tetrahydrofurfuryl alcohol and 5-hydroxy-2-pentanone, respectively. External and internal mass transfer criterion indicate intrinsic rate parameters were estimated and indicate the model can be used to perform monolithic reactor design for aqueous phase hydrogenation of furfural.

Impact of Lignocellulose Pretreatment By-Products on S. cerevisiae Strain Ethanol Red Metabolism during Aerobic and An-aerobic Growth.

Understanding the specific response of yeast cells to environmental stress factors is the starting point for selecting the conditions of adaptive culture in order to obtain a yeast line with increased resistance to a given stress factor. The aim of the study was to evaluate the specific cellular response of Saccharomyces cerevisiae strain Ethanol Red to stress caused by toxic by-products generated during the pretreatment of lignocellulose, such as levulinic acid, 5-hydroxymethylfurfural, furfural, ferulic acid, syringaldehyde and vanillin. The presence of 5-hydroxymethylfurfural at the highest analyzed concentration (5704.8 ± 249.3 mg/L) under aerobic conditions induced the overproduction of ergosterol and trehalose. On the other hand, under anaerobic conditions (during the alcoholic fermentation), a decrease in the biosynthesis of these environmental stress indicators was observed. The tested yeast strain was able to completely metabolize 5-hydroxymethylfurfural, furfural, syringaldehyde and vanillin, both under aerobic and anaerobic conditions. Yeast cells reacted to the presence of furan aldehydes by overproducing Hsp60 involved in the control of intracellular protein folding. The results may be helpful in optimizing the process parameters of second-generation ethanol production, in order to reduce the formation and toxic effects of fermentation inhibitors.

Activated Carbon Cryogel as a Potential Adsorbent for Removal of Aspirin

Pharmaceutical substances are urged to be removed from wastewater as the pollutants bring adverse effects to both humans and the environment. Among the pharmaceutical substances, aspirin is selected as the targeted pharmaceutical waste due to its extremely high consumption. Aspirin is widely used in the world and is produced about 35,000 t/y. Carbon cryogel was chosen as the potential adsorbent to remove aspirin from wastewater, and it was synthesized from urea and furfural before activation with H3PO4. The effects of experimental parameters on aspirin adsorption such as pH, contact time, initial concentration, adsorbent dosage, and temperature were investigated. A maximum of 30 % of percentage removal and 30 mg/g of adsorption capacity were achieved at an initial concentration of 60 mg/L, pH 6, and 0.05 g of adsorbent at room temperature after 45 min of contact time. The activated carbon cryogel synthesized in this study is useful for application in wastewater treatment and sanitation of

Thermodynamic Evaluation of the Intermediate Liquid Compounds (ILC) from Biomass Fast Pyrolysis

Biomass fast pyrolysis process is a technology that converts renewable solids into a dense liquid. This study aims to apprehend the thermodynamic behaviour of the Intermediate Liquid Compounds (ILCs) observed during the biomass fast pyrolysis. The system studied was a closed system (20 mL) with air and a mixture solution of five components (Acetic acid (AA), hydroxyacetone (HX), phenol; furfural (FF) and methanol) at 90°C and under atmospheric pressure. The flash calculation was conducted at a given temperature and pressure. The vapor-liquid equilibrium compositions were determined combining equation of state and activity coefficient models, the Soave-Redlich-Kwong (SRK) equation of state coupled with Modified Huron-Vidal (MHV2) mixing rules incorporating the UNIversal Functionnal Activity Coefficient (UNIFAC) model. Theoretical calculations of vapor-liquid equilibrium compositions were experimentally validated by using a Head-Space GC-MS system. A quantitative agreement between simulated and measured concentrations in the liquid phase was achieved with this combined state-predictive model of SRK-MHV2-UNIFAC model; thus, confirming that it accounts well for the nonidealities.

Occurrence of acrylamide, hydroxymethylfurfural and furaldehyde as process contaminants in traditional breakfast cereals: “Bsissa”

Hydroxymethylfurfural (HMF), furaldehyde (FAL) and acrylamide (AA) are produced during the food roasting process. The content of these toxic products in a common ready-to-eat breakfast, known as “Bsissa”, was investigated. This North African traditional food is mainly based on roasted cereals, leguminous and spices. In the present study, thirty-four commercial “Bsissa” have been investigated for their toxic HMF, FAL and AA content using RP-HPLC-DAD. Additionally, to distinguish the main way of the production of these toxic products (Maillard reaction or caramelization origin), total protein, carbohydrates and reducing sugar were quantified and found in the range 5.63–25.72 g, 45.75–84.33 g and 0.37–3.74 g per 100 g of Bsissa, respectively. This result makes it also suitable to cover daily needs as a breakfast food. Obtained results showed that HMF and FAL were detected in most samples, with values not exceeding 24.71 mg/100 g and to 3.91 mg/100 g, respectively. AA was not detected in all the studied samples. Principal components (PC) and hierarchical classification were employed to establish the samples’ heat damage based on relations between variables. Two PCs were obtained which explain more than 75% of the total variance, thus grouping the Bsissa in two clusters based on the main used cereal. This analysis may help in the mitigation step of furanic compounds by choosing the appropriate Bsissa ingredients.

Differential hierarchical metabolites expression of red/white Salacca sumatrana arillus and its molecular docking studies

Abstract. Fendiyanto MH, Satrio RD, Widana IDKK, Pratami MP, Nikmah IA, Darmadi D. 2021. Differential hierarchical metabolites expression of red/white Salacca sumatrana Arillus and its molecular docking studies. Biodiversitas 22: 1014-1024. Salak Sidempuan (Salacca sumatrana) is one of the medicinal plants originating from tropical countries. However, there is very little research on the study of finding bioactive compounds in S. sumatrana using the metabolomic approach. Here, we use two population types of S. sumatrana, e.g., fruit with red and white arillus. We extracted the compounds from the two tissues using the GC-MS technique and further analyzed their antiviral potential using an in-silico molecular docking technique. Fold change analysis showed that in white arillus there were 21 upregulated compounds and 25 downregulated compounds. Metabolites that have high expression in white arillus tissue are ranxinic acid, nicotinic alcohol, stearic acid, 2-furan carboxaldehyde, and others. Six accessions from S. sumatrana based on PCA analysis and separate dendrogram according to the type of arillus, i.e., red and white arillus. Two compounds that act as antivirals found in this study are stearic acid and palmitic acid based on preliminary molecular docking studies. These two compounds could be used for further studies as a preventive measure against SARS-Cov-2 in the future, however, it needs further comprehensive and clinical analysis the future. In conclusion, metabolites in white arillus were distinctly different from red arillus of Snake fruits. In addition, studies on differential metabolite expression on two types of arillus (red/white) can be used as markers in identifying arillus color early by plant breeders.

Caracterização de compostos voláteis e compostos bioativos da polpa e geleia de cagaita por microextração em fase sólida no modo headspace e espectrometria de massa por paper spray

A cagaiteira (Eugenia dysenterica) pertencente à família Myrtaceae, é uma árvore nativa do Cerrado brasileiro, o seu fruto é muito frágil, apresentando casca fina e polpa suculenta, é consumido na forma processada como geleia para prolongar a vida útil. O presente trabalho teve como objetivo elaborar geleia de cagaita e avaliar a alteração de compostos bioativos e compostos voláteis em relação à polpa in natura. A análise de espectrometria de massa por paper spray nos modos positivos e negativos permitiu a identificação de 27 compostos, dentre elas, ácidos orgânicos, açúcares, antocianinas, ácidos hidroxicinâmicos, ácidos hidroxibenzóicos e flavonoides, indicando que a produção de geleia pode ser uma técnica para conservação de compostos fenólicos com suas respectivas qualidades sensoriais como cor e sabor. Na análise de voláteis por microextração em fase sólida no modo headspace, foram detectados no total de 33 compostos, principalmente das classes de monoterpenos, de sesquiterpenos e de ésteresindicando que a produção da geleia pode conservar o aroma característico do fruto. Na caracterização dos compostos voláteis da polpa de cagaita, o 3-careno foi o monoterpeno majoritário encontrado. Enquanto no processamento da geleia houve produção do furaldeído, produto obtido como consequência natural do aquecimento.

One-step complexed preparation of nitrogen and Cu co-doped oxidative active carbon catalysts Cu-N/OAC for furfural selective hydrogenation with high yield

A facile procedure for preparing copper and nitrogen co-doped active carbon (Cu-N/OAC) by one-step complexed was reported and applied in liquid-phase hydrogenation of furfural (FAL). The facile procedure resulted in high Cu nanoparticles dispersion on OAC with Cu0 and Cu+ sites and apparently promoted the catalytic activities during furfural hydrogenation reaction. The obtained Cu-N/OAC-800 shows 99.5% FAL conversion with 98.4% selectivity to furfuryl alcohols (FOL) under reaction condition of 150 °C, 2 MPa and 6 h. These results indicated that the excellent catalytic performance of the catalyst was due to the synergic effects of nitrogen doping and Cu metal active sites.

Converting Co2+-impregnated g-C3N4 into N-doped CNTs-confined Co nanoparticles for efficient hydrogenation rearrangement reactions of furanic aldehydes

The cyclopentanone and derivatives are a class of crucial fine chemicals for various industries and currently produced by conventional petrochemical synthetic routes. Here, we demonstrated a new synthetic approach to directly fabricate N-doped carbon nanotube (N-CNTs) networks with confined Co nanoparticles from Co2+-impregnated bulk g-C3N4 as high performance hydrogenation rearrangement (HR) catalyst to efficiently convert a wide spectrum of biomass-derived furanic aldehydes to the corresponding cyclopentanones in water under a record-low H2 pressure of 0.5 MPa and mild temperature. We unveiled a Co-catalysed bulk g-C3N4 decomposition/carbonisation CNTs formation mechanism. A new HR pathway was also unveiled.