scholarly journals Supported Bimetallic Catalysts for the Solvent-Free Hydrogenation of Levulinic Acid to γ-Valerolactone: Effect of Metal Combination (Ni-Cu, Ni-Co, Cu-Co)

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1354
Author(s):  
Mahlet N. Gebresillase ◽  
Reibelle Q. Raguindin ◽  
Hern Kim ◽  
Jeong Gil Seo
Keyword(s):  
Bimetallic Catalysts ◽  
Levulinic Acid ◽  
Value Added ◽  
Single Step ◽  
Solvent Free ◽  
Catalyst Loading ◽  
Fuel Additive ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Highly Active

γ-valerolactone (GVL) is an important value-added chemical with potential applications as a fuel additive, a precursor for valuable chemicals, and polymer synthesis. Herein, different monometallic and bimetallic catalysts supported on γ-Al2O3 nanofibers (Ni, Cu, Co, Ni-Cu, Ni-Co, Cu-Co) were prepared by the incipient wetness impregnation method and employed in the solvent-free hydrogenation of levulinic acid (LA) to GVL. The influence of metal loading, metal combination, and ratio on the activity and selectivity of the catalysts was investigated. XRD, SEM-EDS, TEM, H2-TPR, XPS, NH3-TPD, and N2 adsorption were used to examine the structure and properties of the catalysts. In this study, GVL synthesis involves the single-step dehydration of LA to an intermediate, followed by hydrogenation of the intermediate to GVL. Ni-based catalysts were found to be highly active for the reaction. [2:1] Ni-Cu/Al2O3 catalyst showed 100.0% conversion of LA with >99.0% selectivity to GVL, whereas [2:1] Ni-Co/Al2O3 yielded 100.0% conversion of LA with 83.0% selectivity to GVL. Moreover, reaction parameters such as temperature, H2 pressure, time, and catalyst loading were optimized to obtain the maximum GVL yield. The solvent-free hydrogenation process described in this study propels the future industrial production of GVL from LA.

Recyclable Heterogeneous Fe-Mo Nanocatalyst: Application in Solvent Free Synthesis of β-enaminones

2019 ◽  
Vol 6 (3) ◽  
pp. 238-247
Author(s):  
Swapnil R. Bankar
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Significant Loss ◽  
Solvent Free ◽  
Catalyst Loading ◽  
Spectroscopic Techniques ◽  
Impregnation Method ◽  
Molybdenum Catalyst ◽  
X Ray ◽  
Solvent Free Condition

<P>Background: In recent years, green organic transformation has become a challenge for a chemist in areas like social sector, health, and environment. Literature survey revealed that a nano magnetite supported heterogeneous catalysis is an emergent field with huge application in chemical synthesis. </P><P> Objective: In the present article, the aim was to develop a simple and facile method to carry organic reaction under benign media. So, the focus was on the synthesis of nano-magnetite supported molybdenum catalyst and its application in β-enaminones synthesis. </P><P> Methods: Magnetically recyclable heterogeneous ferrite-molybdenum catalyst was prepared by simple impregnation method. The synthesized nanocatalyst Fe-Mo was well analysed by spectroscopic techniques like X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission gun scanning electron microscopy and vibrating-sample magnetometry. The functionalized nanocatalyst Fe-Mo was employed in the synthesis of β-enaminones under solvent free condition. </P><P> Results: The competency of synthesized nanocatalyst-Fe-Mo was observed to be good for the synthesis of β-enaminones derivatives under microwave irradiation and gave excellent yield (86-96%) of the product. The catalyst was recycled for more than five consecutive runs without significant loss in its activity. </P><P> Conclusion: In the present research article, synthesis of highly active, magnetically recyclable Fe- Mo nanocatalyst was obtained from easily available precursor. The MNP was stable under investigated conditions and effective in β-enaminones synthesis. The simple eco-friendly method, low catalyst loading, short transformation time, and reusability of the catalyst thoroughly follow the sustainable protocol.</P>

scholarly journals Synthesis and evaluation of highly dispersed SBA-15 supported Ni–Fe bimetallic catalysts for steam reforming of biomass derived tar reaction

2016 ◽  
Vol 6 (12) ◽  
pp. 4327-4336 ◽  
Author(s):  
Y. Kathiraser ◽  
J. Ashok ◽  
S. Kawi
Keyword(s):  
Oleic Acid ◽  
Steam Reforming ◽  
Bimetallic Catalysts ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Metal Precursor ◽  
Highly Dispersed ◽  
Incipient Wetness ◽  
Supported Ni

Highly dispersed Ni–Fe bimetallic catalysts supported on mesoporous SBA-15 were synthesized via an incipient wetness impregnation method by impregnation of a small amount of oleic acid mixed with a metal precursor on the SBA-15 support.

Conversion of Glycerol into Value-Added Products Over Cu–Ni Catalyst Supported on γ-Al2O3 and Activated Carbon

2014 ◽  
Vol 12 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Satyanarayana Murty Pudi ◽  
Tarak Mondal ◽  
Prakash Biswas ◽  
Shalini Biswas ◽  
Shishir Sinha
Keyword(s):  
Activated Carbon ◽  
Mixed Oxide ◽  
Bimetallic Catalysts ◽  
Weight Ratio ◽  
Superior Performance ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Acidic Nature

Abstract A series of Cu, Ni monometallic and bimetallic catalysts supported on γ-Al2O3 and activated carbon were synthesized by incipient wetness impregnation method and examined for hydrogenolysis and esterification of glycerol. Hydrogenolysis reaction was carried out in a 250 ml Teflon-coated stainless steel batch reactor at 250°C and 10 bar H2 pressure, whereas esterification of glycerol with acetic acid was carried out at 120°C at atmospheric pressure. The physiochemical properties of the catalysts were investigated by various techniques such as surface area, X-ray diffraction (XRD), NH3-temperature-programmed desorption (TPD). Characterization results dictated that the reduction behavior, acidic nature and the metal support interactions were varied with the support as well as Cu/Ni weight ratio. The XRD results confirmed the formation of mixed oxide Cu0.75Ni0.25 Al2O4 phase in Cu–Ni (3:1)/γ-Al2O3 catalyst. Among the catalysts tested, Cu–Ni bimetallic catalysts showed superior performance as compared to monometallic catalysts in both the reactions. The glycerol hydrogenolysis activity of γ-Al2O3 supported Cu–Ni catalysts was higher than the activated carbon-supported catalysts. 1,2-PDO was obtained as the main hydrogenolysis product independent of the support as well as Cu/Ni weight ratio and its selectivity was in the range of 92.8–98.5%. The acidic nature of γ-Al2O3 and the mixed oxide (Cu0.75Ni0.25Al2O4) phase played an important role for hydrogenolysis activity. Cu–Ni (3:1)/γ-Al2O3 catalyst showed the maximum 1,2-PDO selectivity to 97% with 27% glycerol conversion after a reaction time of 5 h. On the other hand, Cu–Ni(1:3)/C catalyst showed the highest glycerol conversion of 97.4% for esterification and obtained selectivity to monoacetin, diacetin and triacetin were 26.1%, 67.2% and 6.5%, respectively.

scholarly journals Ni-Pd/γ-Al2O3 Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural towards Value Added Chemicals

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1026
Author(s):  
Emilia Soszka ◽  
Marcin Jędrzejczyk ◽  
Ireneusz Kocemba ◽  
Nicolas Keller ◽  
Agnieszka Ruppert
Keyword(s):  
Bimetallic Catalysts ◽  
Levulinic Acid ◽  
Active Sites ◽  
Surface Acidity ◽  
High Surface ◽  
Value Added ◽  
Ni Catalyst ◽  
Residual Chlorine ◽  
Alumina Support ◽  
Pd Catalysts

γ-Al2O3 supported Ni-Pd catalysts with different Ni:Pd ratios were studied in the hydrogenation of two industrially-relevant platform molecules derived from biomass, namely levulinic acid and hydroxymethylfurfural. The bimetallic catalysts showed better performances in both processes in comparison to the monometallic counterparts, for which a too strong interaction with the alumina support reduced the activity. The behavior of the bimetallic catalysts was dependent on the Ni:Pd ratio, and interestingly also on the targeted hydrogenation reaction. The Pd-modified Ni-rich system behaves like pure Ni catalyst, but with a strongly boosted activity due to a higher number of Ni active sites available, Pd being considered as a spectator. This high activity was manifested in the levulinic acid hydrogenation with formic acid used as an internal hydrogen source. This behavior differs from the case of the Pd-rich system modified by Ni, which displayed a much higher Pd dispersion on the support compared to the monometallic Pd catalyst. The higher availability of the Pd active sites while maintaining a high surface acidity allows the catalyst to push the HMF hydrodeoxygenation reaction forward towards the green biopolymer precursor 2,5-bis(hydroxymethyl)-tetrahydrofuran, and in consequence to strongly modify the selectivity of the reaction. In that case, residual chlorine was proposed to play a significant role, while Ni was considered as a spectator.

scholarly journals Acid-Catalyzed Conversion of Cellulose Into Levulinic Acid With Biphasic Solvent System

2021 ◽  
Vol 12 ◽  
Author(s):  
Changyue Ma ◽  
Bo Cai ◽  
Le Zhang ◽  
Junfeng Feng ◽  
Hui Pan
Keyword(s):  
Levulinic Acid ◽  
Value Added ◽  
Acid Catalyst ◽  
Solvent System ◽  
High Yield ◽  
Catalyst Loading ◽  
Amberlyst 15 ◽  
Hydrolysis Of Cellulose ◽  
Acid Catalyzed ◽  
Hydrolysis Of

In this work, acid-catalyzed conversion of cellulose into levulinic acid in a biphasic solvent system was developed. Compared to a series of catalysts investigated in this study, the Amberlyst-15 as a more efficient acid catalyst was used in the hydrolysis of cellulose and further dehydration of derived intermediates into levulinic acid. Besides, the mechanism of biphasic solvent system in the conversion of cellulose was studied in detail, and the results showed biphasic solvent system can promote the conversion of cellulose and suppress the polymerization of the by-products (such as lactic acid).The reaction conditions, such as temperature, time, and catalyst loading were changed to investigate the effect on the yield of levulinic acid. The results indicated that an appealing LA yield of 59.24% was achieved at 200°C and 180 min with a 2:1 ratio of Amberlyst-15 catalyst and cellulose in GVL/H2O under N2 pressure. The influence of different amounts of NaCl addition to this reaction was also investigated. This study provides an economical and environmental-friendly method for the acid-catalyzed conversion of cellulose and high yield of the value-added chemical.

scholarly journals Preparation of bimetallic Ni–Fe/MCM-41 catalysts and their catalytic activity for CO methanation

2019 ◽  
Vol 45 ◽  
pp. 146867831987032
Author(s):  
Zhang Jiaying
Keyword(s):  
Bimetallic Catalysts ◽  
Space Velocity ◽  
Molar Ratio ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Activity Increase ◽  
Co Methanation ◽  
Weight Hourly Space Velocity ◽  
Temperature Programmed ◽  
Mcm 41

A series of Ni–Fe/MCM-41 bimetallic catalysts and also Ni/MCM-41 and Fe/MCM-41 catalysts were prepared by the incipient-wetness impregnation method and tested for their activity for CO methanation in a continuous-flow microreactor. The results showed that the catalytic activities of the Ni–Fe/MCM-41 bimetallic catalysts were much higher than those of the Ni/MCM-41 and Fe/MCM-41 catalysts at low temperatures (200°C–325°C). The 10%Ni–5%Fe/MCM-41 catalyst showed the best activity with a CO conversion of almost 100% and a CH4 selectivity of 98% at 350°C under a pressure of 1.5 MPa with a 3:1 molar ratio of H2 to CO and a weight hourly space velocity of 12,000 mL h−1 g−1. The catalysts were characterized by N2 physisorption measurements, X-ray diffraction, and H2-temperature-programmed reduction. The results showed that the addition of Fe will lead to the formation of finer Ni particles and Ni–Fe alloy, which were the main reasons for the activity increase in the Ni–Fe/MCM-41 catalysts.

Microwave-assisted green synthesis of levulinate esters as biofuel precursors using calix[4]arene as an organocatalyst under solvent-free conditions

2021 ◽  
Vol 5 (1) ◽  
pp. 108-111
Author(s):  
Gabriel Abranches Dias Castro ◽  
Sergio Antonio Fernandes
Keyword(s):  
Green Synthesis ◽  
Levulinic Acid ◽  
Acid Catalysis ◽  
Value Added ◽  
Solvent Free ◽  
Microwave Assisted ◽  
Solvent Free Conditions

Levulinic acid, one of the top 12 value-added chemicals, can be obtained by the transformation of biomass by acid catalysis.

scholarly journals Dictating Selectivity in the Catalytic Vapor-Phase Conversion of Glycerol

2021 ◽  
Vol 7 (1) ◽  
pp. 1-10
Author(s):  
Della Pina Cristina ◽  
Falletta Ermelinda ◽  
Rossi Michele
Keyword(s):  
Vapor Phase ◽  
Energy Savings ◽  
Ambient Pressure ◽  
Fixed Bed ◽  
Value Added ◽  
Catalyst Stability ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Phase Conversion ◽  
Experimental Conditions

A viable route for the vapor-phase conversion of glycerol into value-added chemicals is herein presented. This procedure allows to dictate selectivity towards hydroxyacetone (acetol) or methylglyoxal (pyruvaldehyde) by simply tuning the experimental conditions while retaining the same catalytic system. A series of gold- and copper-based catalysts supported on gamma-alumina, including bimetallic formulations, were prepared by incipient wetness impregnation method and tested in a continuous-flow fixed-bed vertical glass reactor at ambient pressure and T = 250-300°C. The best performance was achieved with 1%wt Au/Al2O3. Accordingly, the selectivity could be directed to acetol (sel. 72%) at 87% conversion when performing the reaction at 300°C and adding H2 to the carrier N2, or towards pyruvaldehyde (sel. 79%) at 92% conversion when adding O2 to N2 at 250°C. These relatively mild conditions not only allow for energy savings with respect to the common procedures so far reported, but also for catalyst stability that can be easily regenerated after use. Furthermore, the low metal loading in the catalyst (1% wt) and its small amount requested for each test (0.1 g catalyst) make this procedure economically sustainable.

Analysis of NiMoP/γ-Al2O3 Catalyst Preparation with Impregnation and Microwave Polyol Methods for Bio-Jet Production

2020 ◽  
Vol 1000 ◽  
pp. 257-264
Author(s):  
Bambang Heru Susanto ◽  
Joshua Raymond Valentino Siallagan
Keyword(s):  
Coconut Oil ◽  
Catalyst Preparation ◽  
Operating Conditions ◽  
Catalyst Loading ◽  
Impregnation Method ◽  
Conversion Yield ◽  
Jet Production ◽  
Cracking Process ◽  
Catalyst Impregnation ◽  
Rate Conversion

Bio-Jet could be produced by the synthesis of vegetable oil through the hydrodeoxygenation, decarboxylation, decarbonization, and catalytic cracking process. Physical characteristics, activities, and selectivity of the catalyst used will determine the rate, conversion, and yield of the reaction that being carried out. This study aims to compare and obtain the best characteristics of NiMoP/γ-Al2O3 catalysts synthesized using two types of preparation, impregnation and microwave polyol methods, which will be used for bio-jet production. The impregnation method takes more than 24 hours for catalyst preparation, while microwave polyols that use microwaves can synthesize catalysts faster. Both catalysts have almost the same loading on the weight of the catalyst, which in the microwave polyol method has a more dispersed promotor and active site, although the crystallinity level is deficient and tends to be amorphous compared to the impregnation method with high crystallinity. In bio-jet synthesis reaction with operating conditions of 5% catalyst loading by comparison to Coconut Oil, 400°C, and 15 bar, the conversion, yield, and selectivity of catalyst impregnation were 91.705%, 47.639%, and 84.511%, while microwave polyol catalysts were 90.296%, 42.752%, and 82.517%, respectively. In conclusion, microwave polyol provides a more effective and efficient preparation method.

Graphdiyne Anchored Ultrafine Ag Nanoparticles for High Efficient and Solvent-Free Catalysis of CO2 Cycloaddition

2021 ◽  
Author(s):  
Chang Liu ◽  
Chao Zhang ◽  
Tongbu Lu
Keyword(s):  
Ag Nanoparticles ◽  
Co2 Reduction ◽  
Value Added ◽  
Solvent Free ◽  
Alternative Route ◽  
Practical Application ◽  
Co2 Utilization ◽  
High Efficient

Apart from photo-/electro-catalytic CO2 reduction, an important alternative route to CO2 utilization is to use this inert molecule as a C1 source to synthesize value-added chemicals, while the practical application...

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