Hydrogenolysis Of Cellulose Research Articles

Efficient production of ethylene glycol from cellulose over Co@C catalysts combined with tungstic acid

The encapsulated Co@C catalyst was firstly applied for the direct production of ethylene glycol (EG) from cellulose hydrogenolysis. The multi-step reaction can be well-balanced by regulating the synergy between Co@C and tungstic acid (TA).

Pt nanoparticles supported on Nb-modified TiO2 as an efficient heterogeneous catalyst for the conversion of cellulose to light bioalcohols.

Nb-modified anatase-supported Pt nanoparticles were synthesized for the efficient conversion of cellulose to light bioalcohols. Characterization confirmed the presence of SMSIs in the catalysts, offering adjacent hydrogenation sites, Brønsted and Lewis acid sites. Treating the catalysts in humid air enhanced the acidic concentration, accelerating the key step during the reaction.

Kinetic Modeling for the “One-Pot” Hydrogenolysis of Cellulose to Glycols over Ru@Fe3O4/Polymer Catalyst

Despite numerous works devoted to the cellulose hydrogenolysis process, only some of them describe reaction kinetics. This is explained by the complexity of the process and the simultaneous behavior of different reactions. In this work, we present the results of the kinetic study of glucose hydrogenolysis into ethylene- and propylene glycols in the presence of Ru@Fe3O4/HPS catalyst as a part of the process of catalytic conversion of cellulose into glycols. The structure of the Ru-containing magnetically separable Ru@Fe3O4/HPS catalysts supported on the polymeric matrix of hypercrosslinked polystyrene was studied to propose the reaction scheme. As a result of this study, a formal description of the glucose hydrogenolysis process into glycols was performed. Based on the data obtained, the mathematical model of the glucose hydrogenolysis kinetics in the presence of Ru@Fe3O4/HPS was developed and the parameter estimation was carried out. The synthesized catalyst was found to be characterized by the enhanced magnetic properties and higher catalytic activity in comparison with previously developed catalytic systems (i.e., on the base of SiO2). The summarized selectivity towards the glycols formation was found to be ca. 42% at 100% of the cellulose conversion in the presence of Ru@Fe3O4/HPS.

Selective Cellulose Hydrogenolysis to 2,5-Hexanedione and 1-Hydroxy-2-hexanone Using Ni@NC Combined with H3PO4

Selective Cellulose Hydrogenolysis to 2,5-Hexanedione and 1-Hydroxy-2-hexanone Using Ni@NC Combined with H₃PO₄

Hydrocarbon Distribution of Cellulose Hydrogenolysis over Ru–MoOx/C Combined with HZSM-5

Hydrocarbon Distribution of Cellulose Hydrogenolysis over Ru–MoO_<i>x</i>/C Combined with HZSM-5

Synergistic Effect of Ni/W/Cu on MgAl2O4 for One-Pot Hydrogenolysis of Cellulose to Ethylene Glycol at a Low H2 Pressure.

Nickel and tungsten, combined with copper, were incorporated into a magnesium aluminum spinel to form a multifunctional catalyst (Ni–W–Cu/MgAl2O4). Characterization results suggested that the adjacent Cu not only facilitated the reduction of W6+ to W5+ with substantial oxygen vacancies but also promoted the reducibility of the Ni species. Besides, the incorporation of Ni, W, and Cu into the support enhanced the catalytic acidity, as well as the L acid sites. The catalyst exhibited a strong synergistic effect between the three metals and the support, resulting in higher catalytic activity for the one-pot hydrogenolysis of cellulose to ethylene glycol. High cellulose conversion (100%) and ethylene glycol yield (52.8%) were obtained, even under a low H2 pressure of 3 MPa.

Reaction network and kinetics for the one-pot hydrogenolysis of cellulose to ethylene glycol over NiOx-WOy-Cu/MgAl2O4

The reaction pathway and kinetics of cellulose hydrogenolysis to ethylene glycol (EG) catalyzed by nickel and tungsten combined with copper supported on magnesium aluminum spinel (NiOx-WOy-Cu/MgAl2O4) were studied. Cellulose was hydrolyzed to glucose, which followed either the retro-aldol condensation to glycolaldehyde and erythrose or isomerized to fructose followed by retro-aldol reaction to dihydroxyacetone and glyceraldehydes. The derived glucose can also be hydrogenated to sorbitol. The intermediate products were subsequently converted to EG, erythritol, glycerol and 1,2-propanediol. The cellulose conversion, yields of EG and C2,3 polyols were achieved 100, 53.1 and 62.7%, respectively. The simplified kinetic models were proposed and validated with the experimental results, indicating that the simpler first-order model could perfectly describe the hydrogenolysis of cellulose in the catalytic system. Hydrolysis of cellulose was demonstrated as the rate determining step independent of the reaction pathway, and high temperatures were favorable to the hydrolysis of cellulose to glucose. Activation energies results showed that high temperatures were favorable to the hydrolysis of cellulose to glucose.

Production of bio-ethanol by consecutive hydrogenolysis of corn-stalk cellulose

Current bio-ethanol production entails the enzymatic depolymerization of cellulose, but this process shows low efficiency and poor economy. In this work, we developed a consecutive aqueous hydrogenolysis process for the conversion of corn-stalk cellulose to produce a relatively high concentration of bio-ethanol (6.1 wt%) without humin formation. A high yield of cellulose (ca. 50 wt%) is extracted from corn stalk using a green solvent (80 wt% 1,4-butanediol) without destroying the structure of the lignin. The first hydrothermal hydrogenolysis step uses a Ni–WOx/SiO2 catalyst to convert the high cumulative concentration of cellulose (30 wt%) into a polyol mixture with a 56.5 C% yield of ethylene glycol (EG). The original polyol mixture is then subjected to subsequent selective aqueous-phase hydrogenolysis of the C–O bond to produce bioethanol (75% conversion, 84 C% selectivity) over the modified hydrothermally stable Cu catalysts. The added Ni component favors the good dispersion of Cu nanoparticles, and the incorporated Au3+ helps to stabilize the active Cu0-Cu+ species. This multi-functional catalytic process provides an economically competitive route for the production of cellulosic ethanol from raw lignocellulose.

Self-Propagating High-Temperature Synthesis of Composite Materials Based on Tungsten Carbides: Effect of Phase Composition on the Yield of Ethylene and Propylene Glycols in the One-Pot Hydrolysis–Hydrogenolysis of Cellulose

It is shown that the reaction of the hydrolysis–hydrogenolysis of cellulose to alcohols can be catalyzed by the binary system Ca(OH)2–composite material based on tungsten carbides W2C/WC, obtained by combining mechanochemical activation and self-propagating high-temperature synthesis with an exothermic mixture of tungsten oxide, metallic magnesium, and technical carbon. It is demonstrated that the amounts of tungsten carbides (W2C, WC) and the ratio between them can be controlled by introducing inert additives (metallic tungsten or calcium carbonate) to the exothermic mixture. The order of introducing reagents to the exothermic mixture and their activation is found to affect the textural properties of the materials. Self-propagating high-temperature synthesis is shown to be superior to mechanochemical activation. The catalytic properties of these materials are studied in the hydrolysis–hydrogenolysis of cellulose. It is determined that the phase composition of the composite materials affects the yields of ethylene glycol and 1,2-polyethylene glycol and their ratio. The maximum total yield of the glycols (25–31%) is obtained using a sample with a high W2C content.

Selective (ligno) cellulose hydrogenolysis to ethylene glycol and propyl monophenolics over Ni–W@C catalysts

The bi-functional Ni–W@C catalysts were prepared by one-pot reduction–carbonization method and used in hydrogenolysis of cellulose as well as raw lignocellulosic biomass to chemicals. The catalytic performance for cellulose conversion showed that it was more favorable for ethylene glycol (EG) production, obtaining the highest EG yield 60.1% over the Ni–W@C700 catalyst. The Ni–W@C bimetallic catalysts are systematically characterized with BET, XRD, Raman, XPS, TEM techniques and experiments to probe the active catalytic sites of the catalysts. The effects of calcination temperature of Ni–W catalysts, reaction time, temperature and H2 pressure on cellulose hydrogenolysis were investigated in detail. The Ni particles could lead to produce more W5+ active sites, which promotes the glucose retro-aldol condensation to break the target C–C bonds. Metallic Ni catalyzed C=O hydrogenation and C–C hydrogenolysis, which could also avoid the coke formation. The EG selectivity was dependent on the synergy of WOx and Ni metal sites. In addition, this synergistic effect between the metal and WOx could promote lignin component degradation in direct conversion of untreated raw lignocellulosic biomass, obtaining the propyl monophenolics including guaiacylpropane, syringylpropane and p-n-propylphenol with a total yield of 17.3 wt% besides EG.

Catalytic Production of Oxygenated and Hydrocarbon Chemicals From Cellulose Hydrogenolysis in Aqueous Phase.

As the most abundant polysaccharide in lignocellulosic biomass, a clean and renewable carbon resource, cellulose shows huge capacity and roused much attention on the methodologies of its conversion to downstream products, mainly including platform chemicals and fuel additives. Without appropriate treatments in the processes of cellulose decompose, there are some by-products that may not be chemically valuable or even truly harmful. Therefore, higher selectivity and more economical and greener processes would be favored and serve as criteria in a correlational study. Aqueous phase, an economically accessible and immensely potential reaction system, has been widely studied in the preparation of downstream products of cellulose. Accordingly, this mini-review aims at making a related summary about several conversion pathways of cellulose to target products in aqueous phase. Mainly, there are four categories about the conversion of cellulose to downstream products in the following: (i) cellulose hydrolysis hydrogenation to saccharides and sugar alcohols, like glucose, sorbitol, mannose, etc.; (ii) selective hydrogenolysis leads to the cleavage of the corresponding glucose C-C and C-O bond, like ethylene glycol (EG), 1,2-propylene glycol (PG), etc.; (iii) dehydration of fructose and further oxidation, like 5-hydroxymethylfurfural (HMF), 2,5-furandicarboxylic acid (FDCA), etc.; and (iv) production of liquid alkanes via hydrogenolysis and hydrodeoxygenation, like pentane, hexane, etc. The representative products were enumerated, and the mechanism and pathway of mentioned reaction are also summarized in a brief description. Ultimately, the remaining challenges and possible further research objects are proposed in perspective to provide researchers with a lucid research direction.

Self-propagating high-temperature synthesis of composite materials containing tungsten carbides: The effect of phase composition on the yield of ethylene glycol and propylene glycol in the single-step hydrolysis-hydrogenolysis of cellulose

It was shown that the hydrolysis-hydrogenolysis of cellulose to alcohols can be catalyzed by a two-component system Ca(OH) 2 – composite material containing tungsten carbides (W 2 C/WC), which are obtained by a combination of mechanochemical activation and self-propagating high-temperature synthesis (SHS) using an exothermic mixture of tungsten oxide, metallic magnesium and carbon black. The introduction of inert additives (metallic tungsten or calcium carbonate) in the exothermic mixture allowed controlling the amount and ratio of tungsten carbides (W 2 C, WC). The introduction order of reagents in the exothermic mixture and their activation affected the textural properties of materials. Advantages of the SHS method over mechanical activation were demonstrated. The catalytic properties of these materials were studied in the hydrolysis- hydrogenolysis of cellulose. Phase composition of the composite materials was found to affect the yield of ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) and their ratio. The maximum total yield of EG and 1,2-PG (25–31 %) was obtained in the presence of a sample with high W 2 C content.

MAGNETICALLY RECOVERABLE POLYMER CATALYST FOR CELLULOSE HYDROGENOLYSIS

A new type of Ru-containing magnetically recoverable catalyst based on a polymer matrix of hypercrosslinked polystyrene (HPS) for the reaction of the hydrogenolysis of microcrystalline cellulose to ethylene and propylene glycol (EG and PG) is proposed. The catalyst is synthesized sequentially in two stages. At the first stage, by means of thermal decomposition of iron (III) salts in the presence of polyols, magnetite particles (Fe3O4) are formed in the pores of the HPS. At the second stage, Ru-containing nanoparticles of the active phase of the catalyst are synthesized on the surface of Fe3O4/HPS. Samples of the original HPS, Fe3O4/HPS and Ru-Fe3O4/HPS were characterized using various physicochemical methods. In particular, it was shown that the synthesized samples of catalysts have a high specific surface area (450 - 750 m2/g, depending on the magnetite content), retain the micro-mesoporous nature of the original polymer, and have a high saturation magnetization (4.0 ± 0.5 emu /g), which makes them easy to separate from the reaction mass by an external magnetic field. According to the results of transmission electron microscopy (TEM), the average diameter of the nanoparticles of the active phase Ru was 2.0 ± 0.5 nm. The hydrogenolysis of cellulose to glycols was carried out under the following conditions: 255 °C; 60 bar H2; 55 min; 0.3 g of cellulose; 0.07 g of catalyst 3% Ru-Fe3O4/HPS; 30 ml of H2O; 0.07 g of Ca(OH)2. Under these conditions, the selectivities for EG and PG were 22.6 % and 20.0 %, respectively. The degree of cellulose conversion reaches 100 %. The catalyst showed good stability under hydrothermal reaction conditions, is easily separated from the reaction mass by an external magnetic field, and can be used in the processes of cellulose-containing biomass conversion.

Selective Cellulose Hydrogenolysis to Ethanol Using Ni@C Combined with Phosphoric Acid Catalysts

AbstractInvited for this month′s cover is the group of Longlong Ma at the Guangzhou Institute of Energy Conversion, CAS. The Front Cover shows the conversion of renewable biomass into cellulosic ethanol in water over Ni@C catalyst under mild conditions. In this work, a new one‐pot method is developed for production of ethanol from renewable and sustainable cellulose. With the aid of Ni@C catalyst and H3PO4, cellulose is directly converted into ethanol with high yield of 69.1 %, and an ethanol concentration up to 89 g L−1. The Full Paper itself is available at 10.1002/cssc.201901110.

Reaction Route Selection for Cellulose Hydrogenolysis into C2/C3 Glycols by ZnO-Modified Ni-W/\u03b2-zeolite Catalysts

A β-zeolite-supported nickel and tungsten catalyst (Ni-W/β) was employed to generate C2/C3 glycols (ethylene and propylene glycols) in a satisfactory yield from cellulose. After optimizing the acidity of the support, the Ni-W synergy and the co-catalyst, the yield of C2/C3 glycols reached 70.1% (C %), with propylene glycol accounting for 51.1% of the product. This performance was attributed to the effective control of the major reaction steps, namely, hydrolysis, isomerization, retro-aldol condensation and hydrogenation, by the tailored Ni-W-ZnO/β catalyst. The characterization and reaction results indicated that the cellulose hydrolysis step was promoted by the appropriate acidic sites of the β-zeolite, and the reaction routes to C2/C3 glycols were influenced by the mass loading of Ni-W through the synergy of nickel and tungsten oxide, in which Ni is effective in the hydrogenation while W facilitates bond cleavage via a retro-aldol condensation (C6 to C2/C3). Moreover, with the leaching of metal during four cycles of reuse, the catalytic performance was also influenced by the synergy of Ni and W. In addition, the isomerization of glucose to fructose was promoted by ZnO and afforded a high yield of propylene glycol.

Catalytic conversion of cellulose to C5/C6 alkanes over Ir-VOx/SO2 combined with HZSM-5 in n-dodecane/water system

The liquid fuel (made of C5/C6 alkanes) was obtained directly from the hydrogenolysis of microcrystalline cellulose (MCC) with Ir-VOx/SiO2 combined with HZSM-5 as the composite catalyst in a biphasic system (n-dodecane + H2O). The performance of the catalyst was investigated by carrying out a series of experiments using various V/Ir molar ratios, catalyst dosages, reaction temperatures, reaction time, hydrogen pressure and substrates. At the optimized conditions, the cellulose was almost completely converted, and at the same time, a high C5/C6 yield of 85.1% was obtained at 210 °C for 24 h and 6 MPa with the V/Ir molar ratio being 0.13. These results not only proved that Ir-VOx/SiO2 (V/Ir = 0.13) has excellent performance for the hydrogenolysis of MCC to liquid alkanes, but also indicated that vanadium is a good metal promoter for iridium. In addition, it was proven the C5/C6 alkanes were obtained via sorbitol through the combined effect of Ir-VOx/SiO2 and HZSM-5.

Selective Cellulose Hydrogenolysis to Ethanol Using Ni@C Combined with Phosphoric Acid Catalysts.

Ethanol is an important bulk chemical with diverse applications. Biomass-derived ethanol is traditionally produced by fermentation. Direct cellulose conversion to ethanol by chemocatalysis is particularly promising but remains a great challenge. Herein, a one-pot hydrogenolysis of cellulose into ethanol was developed by using graphene-layers-encapsulated nickel (Ni@C) catalysts with the aid of H3 PO4 in water. The cellulose was hydrolyzed into glucose, which was activated by forming cyclic di-ester bonds between the OH groups of H3 PO4 and glucose, promoting ethanol formation under the synergistic hydrogenation of Ni@C. A 69.1 % yield of ethanol (carbon mole basis) was obtained, which is comparable to the theoretical value achieved by glucose fermentation. An ethanol concentration of up to 8.9 wt % was obtained at an increased cellulose concentration. This work demonstrates a chemocatalytic approach for the high-yield production of ethanol from renewable cellulosic biomass at high concentration.

Ru-fe3o4-containing Polymeric Catalysts for Cellulose Hydrogenolysis

In this paper, a novel catalysts on the base of hypercrosslinked polystyrene (HPS) with magnetic properties are proposed for the one-pot processes of the cellulose conversion into ethylene glycol (EG) and propylene glycol (PG). Synthesized magnetically recoverable supports and catalysts were characterized by different physical-chemical methods. The magnetic properties of the supports Fe3O4/HPS MN270 and the corresponding catalysts were studied. The use of this catalyst in the process of microcrystalline cellulose hydrogenolysis in subcritical water allows PG and EG selectivities of 20.0 and 22.6%, respectively, at 100% of cellulose conversion.

Selective Conversion of Cellulose to Hydroxyacetone and 1-Hydroxy-2-Butanone with Sn-Ni Bimetallic Catalysts.

The high-value-added chemicals hydroxyacetone (HA) and 1-hydroxy-2-butanone (HB) were produced from agricultural waste over a Ni3 Sn4 -SnOx catalyst. The Sn-Ni intermetallic compound and SnOx acted as the active sites for HA and HB production by selectively cleaving the target C-C and C-O bonds. Approximately 70 % of the total HA and HB yield was obtained by selective hydrogenolysis of cellulose. This strategy expands the application of cellulose towards renewable production of high-value C3 and C4 keto-alcohols from cellulosic biomass.

Tailoring Catalytic Properties of CuMgAl Hydrotalcites for Selective hydrogenolysis of Cellulose

AbstractThe structure and catalytic properties of CuMgAl ternary hydrotalcites were tailored by adjusting MII/MIII molar ratios. Due to the Jahn‐Teller distortion effect, co‐crystallized impurity phase assigned to Cu2(NO3)(OH)3 was formed for the catalyst with high MII/MIII molar ratio. The formation of impurity phase resulted in the significant change of morphologies and low dispersion of copper species in the hydrotalcites. Nevertheless, the corresponding catalyst exhibited great catalytic proformance in term of ethylene glycol (EG) selectivity for the hydrogenolysis of cellulose. Besides, higher activity was obtained over the catalysts with higher content of Mg due to an increase of the alkalinity.