scholarly journals Catalytic Synthesis of the Biofuel 5-Ethoxymethylfurfural (EMF) from Biomass Sugars

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Dayong Yu ◽  
Xiaofang Liu ◽  
Jingjing Jiang ◽  
Yixuan Liu ◽  
Jinyu Tan ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Catalytic Efficiency ◽  
Deep Eutectic Solvents ◽  
Metal Salts ◽  
Fuel Additive ◽  
Acid Catalysts ◽  
Mixed Acid ◽  
Pros And Cons ◽  
Biomass Sugars ◽  
New Generation

A new generation of bioplatform molecule 5-ethoxymethylfurfural (EMF) has excellent energy density and combustion performance, which makes it a potential fuel additive. This article reviews the factors that affect the production of EMF from different feedstocks, including platform compounds, monosaccharides, polysaccharides, and raw lignocellulosic biomass. Focus is placed on discussing the catalytic efficiency with pros and cons of different acid catalysts, including homogeneous catalysts (i.e., liquid acids and metal salts), heterogeneous catalysts (i.e., zeolites, heteropolyacid-based hybrids, and SO3H-based catalysts), ionic liquids, mixed acid catalysts, and deep eutectic solvents (DESs). Except for the commonly used ethanol solvent, this review also summarizes the influence of the cosolvent system (e.g., ethanol/dimethylsulfoxide (DMSO), ethanol/tetrahydrofuran (THF), and ethanol/γ-valerolactone (GVL)) on the EMF yield.

Green Synthesis of 2-thioxothiazolidin-4-one Derivatives in Deep Eutectic Solvents via Knoevenagel Condensation

2022 ◽  
Vol 19 ◽  
Author(s):  
Melita Lončarić ◽  
MAJA MOLNAR
Keyword(s):  
Chemical Synthesis ◽  
Green Synthesis ◽  
Environmental Pollution ◽  
Knoevenagel Condensation ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Model Reaction ◽  
Methods And Techniques ◽  
New Generation ◽  
Toxic Organic Solvents

Abstract: Recently, more and more researchers are resorting to green methods and techniques to avoid environmental pollution. Accordingly, many researchers have been working on the development of new green synthetic procedures trying to avoid the use of toxic organic solvents. A sustainable concept of green and environmentally friendly solvents in chemical synthesis nowadays encompasses a relatively new generation of solvents called deep eutectic solvents (DESs). DESs often have a dual role in the synthesis, acting as both, solvents and catalysts. In this study, DESs are used in the Knoevenagel synthesis of rhodanine derivatives, with no addition of conventional catalysts. A model reaction of rhodanine and salicylaldehyde was performed in 20 different DESs at 80 °C, in order to find the best solvent, which was further used for the synthesis of the series of desired compounds. A series of rhodanines was synthesized in choline chloride: acetamide (ChCl:acetamide) DES with good to excellent yields (51.4 – 99.7 %).

Synthesis and application of carbon based heterogeneous catalysts for ultrasound assisted biodiesel production

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Namrata D. Gaikwad ◽  
Parag R. Gogate
Keyword(s):  
Electron Microscopy ◽  
Heterogeneous Catalysts ◽  
Temperature Programmed Desorption ◽  
Biodiesel Production ◽  
Acid Catalysts ◽  
Infra Red ◽  
Ultrasound Assisted ◽  
Temperature Programmed ◽  
Scanning Electron ◽  
Carbon Based

AbstractIn the present work, carbon based heterogeneous acid catalysts have been prepared using various synthesis approaches based on the use of sustainable starting materials. The properties of the catalysts have been investigated using Fourier transformed infra-red (FTIR), scanning electron microscopy (SEM), temperature-programmed desorption (NH

scholarly journals Biosynthesis, purification, characterization and immobilization of laccase from Lithothelium sp.

Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Ingrida Radveikienė ◽  
Ingrida Pilotaitė ◽  
Rimgailė Dainytė ◽  
Regina Vidžiūnaitė
Keyword(s):  
Residual Activity ◽  
Catalytic Efficiency ◽  
Hydrophobic Interaction Chromatography ◽  
Metal Salts ◽  
Biotechnological Applications ◽  
Affinity Constants ◽  
Sds Page ◽  
Wide Range ◽  
Optimum Ph ◽  
Sulphate Salts

Novel fungal laccase isoenzymes (namely L95-1 and L95-2) produced by the Ascomycete Lithothelium sp. isolated from the forest soil were purified. However, only one of them was characterized, because the other isoenzyme lost its activity during purification. Extracellular L95-1 laccase was purified 30-fold using ion-exchange and hydrophobic interaction chromatography, with an overall yield of 88%. The molecular mass of purified L95-1 was estimated to be 85 kDa by SDS-PAGE analysis. L95-1 laccase was stable at temperature 4–22°C and pH 6.0–6.5. The substrate specificity of L95-1 laccase was examined with various compounds. Determined affinity constants (KM) varied in a wide range of 3.7–2020.0 µM, whereas catalytic efficiency constants (kcat/KM) covered a range of 0.008–1.9 µM–1 s–1. The optimum pH for most substrates varied in a range from pH 5.0 to 6.0. Sodium azide and fluoride strongly inhibited L95-1 activity, whereas sulphate salts inhibited weakly. The laccase was immobilized on the Fe3O4 nanoparticles and characterized. Residual activity remained at 20% after ten cycles of ABTS oxidation reaction. The immobilized laccase showed higher tolerance to various metal salts. The properties of L95-1 laccase make it potentially useful in the biotechnological applications.

scholarly journals Second-Generation Manganese(III) Porphyrins Bearing 3,5-Dichloropyridyl Units: Innovative Homogeneous and Heterogeneous Catalysts for the Epoxidation of Alkenes

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 967 ◽  
Author(s):  
Neves ◽  
Rebelo ◽  
Faustino ◽  
Neves ◽  
Simões
Keyword(s):  
Heterogeneous Catalysts ◽  
Second Generation ◽  
Supported Catalyst ◽  
Catalytic Efficiency ◽  
Major Product ◽  
Aqueous Hydrogen Peroxide ◽  
Tert Butyl Hydroperoxide ◽  
Merrifield Resin ◽  
Catalytic Cycles ◽  
First Time

The synthesis, characterisation and homogeneous catalytic oxidation results of two manganese(III) porphyrins of the so-called second-generation of metalloporphyrin catalysts, containing one or four 3,5-dichloropyridyl substituents at the meso positions are reported for the first time. The catalytic efficiency of these novel manganese(III) porphyrins was evaluated in the oxidation of cyclooctene and styrene using aqueous hydrogen peroxide as the oxidant, under homogeneous conditions. High conversions were obtained in the presence of both catalysts, obtaining the corresponding epoxide as the major product. The asymmetric metalloporphyrin, chloro[5,10,15-tris(2,6-dichlorophenyl)-20-(3,5-dichloropyridin-4-yl)porphyrinate]manganese(III), CAT-4, evidences a similar activity to that obtained with the well-known and highly efficient second-generation metalloporphyrin catalyst, chloro[5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinate]manganese(III), CAT-2. CAT-4 was covalently attached onto Merrifield resin and 3-bromopropylsilica supports. The solid materials obtained were characterized by several techniques including diffuse reflectance, UV—VIS spectrophotometry, SEM and XPS. The catalytic results for the oxidation of cyclooctene and styrene using the immobilized catalysts are also presented. The Merrifield-supported catalyst showed to be very efficient, leading to five catalytic cycles in the oxidation of cyclooctene, using tert-butyl hydroperoxide as the oxidant.

scholarly journals Microorganism Assisted Synthesized Nanoparticles for Catalytic Applications

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 190 ◽  
Author(s):  
Xiaojiao Fang ◽  
Yin Wang ◽  
Zegao Wang ◽  
Zaixing Jiang ◽  
Mingdong Dong
Keyword(s):  
Energy Consumption ◽  
Environmental Remediation ◽  
Heterogeneous Catalysts ◽  
Catalytic Efficiency ◽  
High Energy ◽  
Surface Areas ◽  
Novel Approach ◽  
Toxic Agents ◽  
Wide Range ◽  
Catalytic Applications

Metal and metalloid nanoparticles (NPs) have attracted substantial attention from research communities over the past few decades. Traditional methodologies for NP fabrication have also been intensely explored. However, drawbacks such as the use of toxic agents and the high energy consumption involved in chemical and physical processes hinder their further application in various fields. It is well known that some bacteria are capable of binding and concentrating dissolved metal and metalloid ions, thereby detoxifying their environments. Bioinspired fabrication of NPs is environmentally friendly and inexpensive and requires only low energy consumption. Some biosynthesized NPs are usually used as heterogeneous catalysts in environmental remediation and show higher catalytic efficiency because of their enhanced biocompatibility, stability and large specific surface areas. Therefore, bacteria used as nanofactories can provide a novel approach for removing metal or metalloid ions and fabricating materials with unique properties. Even though a wide range of NPs have been biosynthesized, and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. The known mechanisms of bioreduction and prospects in the design of NPs for catalytic applications are also discussed.

scholarly journals An Overview of the Water Remediation Potential of Nanomaterials and Their Ecotoxicological Impacts

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1150 ◽  
Author(s):  
Mehrnoosh Ghadimi ◽  
Sasan Zangenehtabar ◽  
Shahin Homaeigohar
Keyword(s):  
Size Range ◽  
Current Knowledge ◽  
Field Studies ◽  
Water Systems ◽  
The Other ◽  
Water Remediation ◽  
One Dimension ◽  
Pros And Cons ◽  
New Generation ◽  
Soil And Water

Nanomaterials, i.e., those materials which have at least one dimension in the 1–100 nm size range, have produced a new generation of technologies for water purification. This includes nanosized adsorbents, nanomembranes, photocatalysts, etc. On the other hand, their uncontrolled release can potentially endanger biota in various environmental domains such as soil and water systems. In this review, we point out the opportunities created by the use of nanomaterials for water remediation and also the adverse effects of such small potential pollutants on the environment. While there is still a large need to further identify the potential hazards of nanomaterials through extensive lab or even field studies, an overview on the current knowledge about the pros and cons of such systems should be helpful for their better implementation.

scholarly journals Bacterial synthesis of nanoparticles: A green approach

2020 ◽  
Vol 28 (1) ◽  
pp. 9-17 ◽  
Author(s):  
S. I. Tsekhmistrenko ◽  
V. S. Bityutskyy ◽  
O. S. Tsekhmistrenko ◽  
L. P. Horalskyi ◽  
N. O. Tymoshok ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Large Scale ◽  
Heterogeneous Catalysts ◽  
Nanoparticle Synthesis ◽  
Catalytic Efficiency ◽  
High Energy ◽  
Synthesis Of Nanoparticles ◽  
Green Approach ◽  
Wide Range ◽  
Catalytic Applications

In recent decades, the attention of scientists has been drawn towards nanoparticles (NPs) of metals and metalloids. Traditional methods for the manufacturing of NPs are now being extensively studied. However, disadvantages such as the use of toxic agents and high energy consumption associated with chemical and physical processes impede their continued use in various fields. In this article, we analyse the relevance of the use of living systems and their components for the development of "green" synthesis of nano-objects with exceptional properties and a wide range of applications. The use of nano-biotechnological methods for the synthesis of nanoparticles has the potential of large-scale application and high commercial potential. Bacteria are an extremely convenient target for green nanoparticle synthesis due to their variety and ability to adapt to different environmental conditions. Synthesis of nanoparticles by microorganisms can occur both intracellularly and extracellularly. It is known that individual bacteria are able to bind and concentrate dissolved metal ions and metalloids, thereby detoxifying their environment. There are various bacteria cellular components such as enzymes, proteins, peptides, pigments, which are involved in the formation of nanoparticles. Bio-intensive manufacturing of NPs is environmentally friendly and inexpensive and requires low energy consumption. Some biosynthetic NPs are used as heterogeneous catalysts for environmental restoration, exhibiting higher catalytic efficiency due to their stability and increased biocompatibility. Bacteria used as nanofactories can provide a new approach to the removal of metal or metalloid ions and the production of materials with unique properties. Although a wide range of NPs have been biosynthetic and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. Known mechanisms of bioreduction and prospects for the development of NPs for catalytic applications are discussed.

Catalytic efficiency of divalent metal salts in dinucleoside 5',5'-triphosphate bond formation

2002 ◽  
Author(s):  
Janusz Stępiński ◽  
Jacek Jemielity ◽  
Magdalena Lewdorowicz ◽  
Marzena Jankowska-Anyszka ◽  
Edward Darżynkiewicz
Keyword(s):  
Bond Formation ◽  
Catalytic Efficiency ◽  
Divalent Metal ◽  
Metal Salts
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