Hydrogenation Of Glucose Research Articles

Optimisation of the processing conditions of hydrolytic hydrogenation of cellulose using carbon nanofiber supported Ni catalysts

The synthesis of sorbitol from cellulose over Ni catalysts is a promising valorisation route in the biorefinery scenario, applying relatively simple preparation methods and earth-abundant metals. The overall selectivity, however, depends on the kinetic control of a complex reaction network, involving the hydrolysis of cellulose to monosaccharides via cello-oligomers, glucose hydrogenation into sorbitol and hydrogenolysis side-reactions of sugars and sorbitol to low molecular weight polyols. Therein, subtle changes in the catalyst composition and process conditions might have a strong impact on the final product distribution. Driven by these challenges, this work first-time provides novel insights into the hydrothermal hydrogenation of cellulose over a carbon nanofibre supported Ni catalyst (Ni/CNF). Firstly, the impact of the duration of a ball-milling pre-treatment step and the influences of the hydrothermal time and temperature were thoroughly analysed. The experimental results obtained highlighted the importance of process control to promote the first transformation of cellulose to glucose and its subsequent hydrogenation to sorbitol to minimise the extension of side reactions. Finally, an additional study was conducted to palliate the recalcitrant nature of cellulose by decreasing mass transfer limitations to a minimum extent. This was achieved by including an additional mix-milling of the amorphous cellulose produced in the first pre-treatment with the catalyst and increasing the H2 pressure of the hydrothermal hydrogenation process. This allowed attaining a sorbitol yield as high as 62% at 190 ºC using an initial H2 pressure of 8 MPa for 26 h, which is one of the best results reported in the literature.

New insights into in mycotoxins production in Alternaria infected apple during postharvest storage

As an apple fruit rot disease related fungus, Alternaria spp. could bring severe hazardous risk to apple fruits during postharvest storage. In this research, cold treatment is investigated for inhibition of Alternaria infection and related mycotoxins production during postharvest storage of apple. Morphology results show that cold treatment could inhibit Alternaria rot in inoculated apple samples. Alternariol Monomethyl Ether (AME), Alternariol (AOH), and Tenuazonic Acid (TEA) are the major mycotoxins during room storage temperature at 25 °C, while only AOH is detected after 30 d at 4 °C storage. The results revealed that room temperature could bring hazardous risk while toxic risks might still exist during cold storage. Metabolites of Alternaria mycotoxins are also identified in this work with metabolic pathways of glucose conjugation, hydrogenation reduction, oxidation, and dehydrogenation reaction. Cold storage treatment could lead to down-regulation of nature products in inoculated apples, including all five target Alternaria mycotoxins. This research proposed new insights into mycotoxins production in Alternaria infected apple during postharvest storage process, which will be benefit for better understanding of postharvest storage and safety control of fruits.

Hydrogenation of Glucose on a Carbon-Supported Ru Catalyst: Optimization of the Reaction Conditions

Hydrogenation of Glucose on a Carbon-Supported Ru Catalyst: Optimization of the Reaction Conditions

Electrocatalytic hydrogenation and oxidation of glucose and xylose on mesoporous carbon-supported Au nanocatalysts

Electrocatalytic conversion of hemicellulose-derived glucose and xylose presents a sustainable approach to utilize renewable energy (e.g. solar, wind) to produce value-added chemicals. In this work, the electrochemical hydrogenation and oxidation of glucose and xylose at ambient conditions were studied using dispersed, mesoporous Sibunit Carbon (SC)-supported Au nanocatalysts (SC/AuNPs) with different cluster sizes (4.4 nm, 5.9 nm, 10-30 nm), providing novel results on the cluster size - activity relation. For the electrocatalytic hydrogenation (ECH) of glucose and xylose into sorbitol and xylitol, respectively, higher conversion rates were obtained when more negative potentials were applied. This indicates that the hydrogenation reaction proceeds concurrently with hydrogen evolution reaction (HER). SC/AuNPs with smaller Au clusters were more active towards glucose or xylose ECH at all potentials applied. The selectivity (Faradaic efficiency) increased towards more negative potentials for glucose ECH but followed an opposite trend for xylose ECH. Analysis using in-situ FTIR-ATR spectroscopy showed that water adsorption which leads to HER, was more extensive in xylose solution than in glucose solution at lower potentials. This would indicate greater inhibition of xylose ECH than glucose ECH at more negative potentials. The electrocatalytic oxidation (ECO) of glucose and xylose to gluconic acid and xylonic acid, respectively, was observed to occur at -0.05, +0.3, and +0.4 V (vs Ag/AgCl) using the present electrocatalytic set up. Constant-potential electrolysis at these potentials showed differences in ECO rate depending on the applied potential and average Au cluster size. The highest glucose and xylose ECO rate was obtained for the SC/AuNPs with the smallest average Au cluster size (4.4 nm) at +0.3 V. Constant-potential electrolysis of the sugars at +0.3 V using this catalyst resulted in 42 % yield of gluconic acid and 32 % yield of xylonic acid in 6 hours, both with a very low Au loading of 0.08 % wt.. These results show the strong influence of Au cluster size on the catalytic activities of SC/AuNPs toward sugar ECH or ECO.

Synthesis of spherical, rod, or chain Ni nanoparticles and their structure–activity relationship in glucose hydrogenation reaction

Structure-activity relationships of Ni particles with different morphologies, crystallinities and compositions were investigated for glucose hydrogenation. Nanorods and nanospheres were obtained respectively by altering hydrogen pressure during synthesis, and nanobead chains were synthesized for analogy analysis following a known procedure. Glucose hydrogenation over Ni nanosphere catalysts exhibits the lowest reaction barrier (Ea = 32 kJ/mol) compared to nanorods and nanobead chains (98 kJ/mol), and a constant sorbitol selectivity of 100 % was obtained at a temperature of 140 °C. A comprehensive characterization with ATR-IR, Raman, XPS, ICP, P-XRD, HRTEM and SAED revealed that the combined factors of poly-crystallinity, amorphous structure and P- dopant make Ni nanospheres superior. This provides a valuable path in the process of designing better non-noble catalysts to definitely avoid the use of noble metals in the future in biomass valorization reactions.

Raney nickel synthesis for glucose hydrogenation without hydrogen gas

Hydrogenation of glucose into sorbitol has been a concern of researchers for a long time because it is an efficient and economical way of producing sorbitol. The researchers look for alternative metals that are higher in abundance and have good hydrogenation activity, such as nickel. In this study, porous nickel was prepared and used as a catalyst for the hydrogenation of glucose to sorbitol without adding hydrogen gas. The porous nickel needs two stages of making. First, prepare the Ni/Al metal alloys from the reduction of Ni(II) and Al(III). Second, the process of removing Al (0) metal from Ni/Al metal mixtures to produce porous Ni, generally called Raney Ni (RaNi). The prepared RaNi characterize using P-XRD and N2 physisorption. X-ray diffraction results show typical nickel (0) diffraction patterns at 2 theta 44.5° (111), 51.8° (200), and 76.4° (220). The results of N2 physisorption on RaNi showed a surface area of ​​64 m2/g and a pore diameter of 6.13 nm. The hydrogenation reaction of glucose without adding hydrogen gas was carried out for 6 hours at 80 °C using isopropyl alcohol as a hydrogen source. The reaction products were analyzed using 1H-NMR by observing the proton chemical shift of the methine and methylene groups of sorbitol at 3.53-3.78 ppm and using the DNS (3-5, dinitrosalysilic acid) test to determine the remaining glucose in the solution. The reaction product tested using DNS showed that the amount of glucose converted was 54% when RaNi was synthetic as a catalyst.

Raney nickel synthesis for glucose hydrogenation without hydrogen gas

Raney nickel synthesis for glucose hydrogenation without hydrogen gas

The effect of Ni particle size and carbon support on catalytic activity for glucose hydrogenation reaction

Ni nanoparticles supported on carbon black (Ni/CB) with Ni particle sizes 6.9–23.5 nm were found to exhibit a size effect, with a significant impact on catalytic performance in the glucose hydrogenation reaction. A series of Ni nanoparticles with different sizes, as determined by statistical analysis of TEM images, were obtained by varying the synthesis temperature using a sol-gel method. The highest glucose conversion and sorbitol production in glucose hydrogenation was possible with Ni/CB catalysts with Ni particles size around 17 nm obtained at 550 °C. Similarly, graphene nanoplatelets (GNP) supported Ni with different particle sizes synthesized under different temperature conditions have an identical behaviour, that is, GNP-550 exhibits the highest catalytic performance. Therefore, it can be concluded that size effect appeared when the particle size is above 10 nm, which provides a reference for the design of subsequent catalysts for liquid phase hydrogenation reactions pertinent to biomass conversion.

Directly converting cellulose into high yield sorbitol by tuning the electron structure of Ru2P anchored in agricultural straw biochar

Directly converting cellulose into sorbitol involves efficient synergy of cellulose hydrolysis and glucose hydrogenation in a bifunctional catalyst. High temperature is favorable and efficient for cellulose hydrolysis, but easily causes the excessive hydrogenation of sorbitol. In this paper, we propose a new strategy to appropriately regulate the hydrogenation activity of Ru catalysts by partially shifting the electrons from Ru to P, which could reduce excessive hydrogenation of sorbitol at 180–200 °C and thus enhance the sorbitol yield. The rice straw biochar was used as carrier and Ru2P/C was synthesized for obtaining sorbitol from glucose by hydrogenation. Subsequently, the bifunctional catalyst Ru2P/C–SO3H was prepared for directly converting cellulose into sorbitol, and the relationship between the composition of the as-prepared catalyst and the sorbitol yield was systematically studied. Satisfactorily, 2 wt% Ru2P/C–SO3H gave sorbitol yields of 96% and 64% at 200 °C within 2 h when glucose and cellulose were used as raw materials, respectively. The characterization results and DFT calculations show that the electrons of Ru atoms in Ru2P are partially transferred to P, which weakens the adsorption and activation of H2 and H* on Ru atoms, thus improving the selectivity of sorbitol. Moreover, Ru2P/C–SO3H has a potential ability in natural biomass waste utilization.

Electrocatalytic hydrogenation of glucose and xylose using carbon fiber supported Au nanocatalysts

Recent evidences have shown catalyst structure sensitivity of electrocatalytic hydrogenation (ECH) of organic molecules in aqueous phase. In this study, ECH of glucose and xylose was investigated using gold nanoparticles (AuNPs) on activated carbon fiber (CF) support as catalyst. CF supported AuNPs catalysts (CF/AuNPs) were synthesized by deposition-precipitation method and were characterized by physicochemical (SEM, TEM, XRD, N2 physisorption, ICP-OES) and electrochemical methods. Chemical or thermal pre-treatment of CF prior to Au deposition resulted in different AuNPs size distributions. The activity towards glucose or xylose ECH were observed to be dependent on the particle size of AuNPs and the applied potential. Compared to a polycrystalline Au catalyst, higher reaction rates for glucose and xylose ECH were observed for a CF/AuNPs catalyst with a higher surface area. This indicates that the activity of Au towards glucose and xylose ECH is dependent on the surface area and particle size, and particle size control can be achieved by simple chemical or thermal pretreatment of the catalyst support.

Selective hydrogenation of glucose to sorbitol with tannic acid-based porous carbon sphere supported Ni–Ru bimetallic catalysts

Ni–Ru bimetallic porous carbon sphere (Ni–Ru@PCS) catalysts were synthesized via formaldehyde-assisted, metal-coordinated crosslinking sol–gel chemistry, in which biomass-derived tannic acid and F127 surfactant were used as carbon precursor and soft template, respectively, and Ni2+ and Ru3+ were used as cross-linkers. In the developed method, Ni–Ru particles became uniformly dispersed in the carbon skeleton due to strong coordination bonds between metal ions (Ni2+ and Ru3+) and tannic acid molecules and bimetal interactions. The as-synthesized Ni–Ru10:1@PCS catalyst with a loading Ni:Ru mole ratio of 10:1 was applied for the selective hydrogenation of glucose to sorbitol, and provided 99% glucose conversion with a sorbitol selectivity of 100% at 140 °C in 150 min reaction time and exhibited good stability and recyclability in which sorbitol yield remained at 98% after 4 cycles with little or no metal agglomeration. The catalyst was applied to glucose solutions as high as 20 wt% with 97% sorbitol yields being obtained at 140 °C in 20 h. The developed bimetallic porous carbon sphere catalysts take advantage of sustainably-derived materials in their structure and are applicable to related biomass conversion reactions.

Selective hydrogenation of reducing sugars over SiO2@Ni/NiO hetero-structured nanoreactor in Mg-driven aqueous phase

Selective hydrogenation is of growing interest in biomass upgrading to be performed over non-precious metal-based catalyst in aqueous phase. Herein, a nickel/nickel oxide hetero-structural catalyst to reducing sugars hydrogenation is designed based on the tailored interfacial synergy and structural composition. Such synergistic silica @ nickel/nickel oxide (SiO2@Ni/NiO) with core–shell structure features in i) interconnected tubes on the shell offering spatial restriction to hydrogen attraction and reactant diffusion, ii) hetero-interfaced Ni/NiO shell balancing the H2 and glucose adsorption chemically, iii) the core shell catalyst providing nano-reactor for reactant enrichment, furthering improving the utilization of nickel active sites. Furthermore, the high solubility of in-situ generated H2 driven by Mg in this aqueous phase hydrogenation system greatly assist the interaction among the reactants. The SiO2@Ni/NiO catalyst exhibits high activity in glucose hydrogenation, under which the conversion rate and sorbitol selectivity can achieve 99 % and 90 % under mild condition of 393 K for 3 h, respectively. It also shows remarkable reuse ability and wide application scope to sugars hydrogenation in this in-situ hydrogen generation process. This proposal gains insights to cooperative catalyst design on chemical composition and nanostructure for advancing biomass-based sugars hydrogenation process.

Electrocatalytic Hydrogenation of Glucose and Xylose on Highly Dispersed Carbon Fiber Supported AU Nanocatalysts

Electrocatalytic Hydrogenation of Glucose and Xylose on Highly Dispersed Carbon Fiber Supported AU Nanocatalysts

The Effect of Ni Particle Size and Carbon Support on Catalytic Activity for Glucose Hydrogenation Reaction

The Effect of Ni Particle Size and Carbon Support on Catalytic Activity for Glucose Hydrogenation Reaction

Tungsten oxide decorated silica-supported iridium catalysts combined with HZSM-5 toward the selective conversion of cellulose to C6 alkanes

Herein, WOx–decorated Ir/SiO2 (W/Ir = 0.06) and HZSM-5 were coupled to selectively convert microcrystalline cellulose (MCC) into C6 alkanes. A 92.8% yield of liquid alkanes including an 85.3% yield of C6 alkanes was produced at 210 °C. Cellulose hydrolysis, glucose hydrogenation and sorbitol hydrodeoxygenation were integrated to produce alkanes via a sorbitol route. Ir-WOx/SiO2 showed high performance for hydrogenation and hydrodeoxygenation reactions after hydrolysis catalyzed by HZSM-5. The intimate contact between WOx and Ir enhanced the synergistic interaction through the electron transfer from Ir to WOx. The interaction strengthened the reduction capability of Ir for hydrogenations, as well as improved the adsorption and activation of C-O bonds on reduced WOx for deoxygenations. The monotungstate WOx species provided moderate Lewis acids to cooperate with Ir to accelerate hydrodeoxygenations with alleviated retro-aldol condensation to yield more C6 alkanes.

Nicotiana genus: a green and sustainable source for designing of nitrogen-rich efficient carbon nanocomposites for the hydrogenation of nitrophenol and non-enzymatic glucose sensing

Transition metals based nitrogen-doped carbon nanocomposites have been envisioned as a potential replacement for precious metal-based nanostructures to catalyze a variety of reactions. Herein, we report the synthesis of a group of nitrogen-doped carbon nanocomposites derived from the Nicotiana genus family plant, e.g. tobacco, a highly nicotine rich entity, and iron nitrate mixture followed by their exploitation for the reduction of 4-nitrophenol (4-NP) and non-enzymatic electrochemical glucose sensing. The controlled study suggests that the pyrolysis of tobacco results in ∼7 at.% of nitrogen doping, an important heteroatom to enhance the catalytic efficiency of nanocomposites. The kinetics of the reduction of 4-NP follow a pseudo-first-order reaction. The time constant is found to increase with the Fe content in the composite owing to the formation of Fe–Nx centers. The separation of a catalyst with the aid of a magnetic field offers a huge add-on to vouch for the recovery of these catalysts. Along with the display of appealing catalytic reduction, its application to non-enzymatic electrochemical glucose sensing is also demonstrated. Overall, the Nicotiana genus can be used as nitrogen-carbon precursors for designing of targeted N-doped carbon-based composites that could be exploited for various applications.

Catalytic Transfer Hydrogenation of Glucose to Sorbitol with Raney Ni Catalysts Using Biomass-Derived Diols as Hydrogen Donors

The catalytic transfer hydrogenation (CTH) of glucose to sorbitol has been studied using a wide collection of different biomass-derived alcohols and diols as hydrogen donors. Catalytic activity results reflect the feasibility to conduct this transformation in the presence of conventional, commercially available Raney Ni-type sponges as catalysts. Sacrificial diols displayed a superior performance as hydrogen donors as compared to short-chain alcohols, including secondary alcohols. Among them, terminal diols such as 1,4-butanediol and 1,5-pentanediol were revealed as excellent hydrogen donors, providing a high selectivity in the conversion of glucose into sorbitol. As for the catalysts, molybdenum promotion provided a very high catalytic activity to sponge nickel catalysts, even under mild temperature conditions. The transformation was also studied in a fixed-bed reactor under continuous-flow operation conditions. Results demonstrate that the catalysts are highly stable and able to operate for at least 550 h on stream with a high selectivity in the CTH of glucose to sorbitol.

Catalytic conversion of glucose into sorbitol over niobium oxide supported Ru catalysts

Abstract Sorbitol is a sugar alcohol of great importance in cosmetic, food and pharmaceutical industry as well as the production of biopolymers. This work aimed at the synthesis of sorbitol from the hydrogenation of glucose using Ru/Nb2O5 catalysts in the amorphous and crystalline phases. The catalysts were synthesized from the wet impregnation method and characterized by N2 adsorption isotherms, TGA/DTG, EDXRF, XRD, TPR-H2, XPS and SEM. The catalytic tests presented results of high conversion rates of glucose reaching 85 % and 99 % of selectivity to sorbitol when using Nb2O5 in the crystalline form as support, and 53 % and 55 % in the conversion and selectivity, respectively, when the amorphous phase of Nb2O5 was used as support. The structural modification of the catalytic support positively favored the catalyst activity and sorbitol production, allowing the formation of nanometric particles of the active metal on the surface alongside the increase of the mesoporosity, thereby facilitating the transport of reagents.

Synergistic effects altering reaction pathways: The case of glucose hydrogenation over Fe-Ni catalysts

Carbon black (CB) supported Ni, Fe, or Fe-Ni alloy catalysts were synthesized by sol-gel to elucidate the reaction pathways over each catalyst, as well as synergistic effects in glucose to sorbitol hydrogenation. The bimetallic materials presented small and alloyed nanoparticles that were richer in reduced metallic sites at the surface than their monometallic counterparts. Glucose isomerization to fructose was favoured over Fe/CB, while glucose hydrogenation to sorbitol is the dominating pathway over Ni/CB catalyst. By contrast, sorbitol production was promoted and undesired isomerization was suppressed when Fe and Ni formed a nanoalloy. In addition, the alloy catalyst presented better stability than the corresponding monometallic catalyst. A comparison with a mechanical mixture of Fe/CB and Ni/CB monometallic catalysts demonstrated the synergy at the nanoscale in the alloy. By comparing different Fe:Ni ratios, the 1:1 formulation was identified as the best compromise to achieve a high activity while maintaining high sorbitol selectivity.

Efficient Sorbitol Producing Process through Glucose Hydrogenation Catalyzed by Ru Supported Amino Poly (Styrene-co-Maleic) Polymer (ASMA) Encapsulated on γ-Al2O3

In this work, a core-shell-like sphere ruthenium catalyst, named as 5%Ru/γ-Al2O3@ASMA, has been successfully synthesized through impregnating the ruthenium nanoparticles (NPs) on the surface of the amino poly (styrene-co-maleic) polymer (ASMA) encapsulating γ-Al2O3 pellet support. The interaction between the Ru cations and the electro-donating polymer shell rich in hydroxyl and amino groups through the coordination bond would guarantee that the Ru NPs can be highly dispersed and firmly embedded on the surface of the support. In addition, the solid sphere γ-Al2O3 pellet could serve as the core to support the resulted catalysts applied in the flow process in a trickle bed reactor to promote the productivity. The resulted catalyst 5%Ru/γ-Al2O3@ASMA can be applied efficiently in the glucose hydrogenation and presents a steadfast sorbitol yield of almost 90% both in batch reactor and the trickle bed reactor, indicating the potential feasibility of the core-shell-like catalyst in the efficient production of sorbitol.