Effective Cu/ZnO/Al2O3 Catalyst for Methanol Production: Synthesis, Activation, Catalytic Performance, and Regeneration
Abstract
5046 39751
Effective Cu/ZnO/Al2O3 Catalyst for Methanol Production: Synthesis, Activation, Catalytic Performance, and Regenerationby
Abstract
A precursor CuO/ZnO/Al2O3 catalyst for methanol synthesis has been prepared at room temperature by introducing a ternary salt solution into the excess of sodium carbonate solution following the reverse co-precipitation method. The catalyst was tested for the synthesis of methanol from synthesis gas. The composition (vol. %) has been presented: CO, 22; CO2, 5.8; N2, 5.5; H2, balance. The methanol productivity was recorded to be 2.7 kg kgcat–1 h–1 at a temperature of 260 °С, a pressure of 3 MPa, and a [...] 5046 39751 |
Perovskite Solar Cells: Assessment of the Materials, Efficiency, and Stabilityby
Abstract
Solar cells based on organic-inorganic lead halide perovskites are popular in the photovoltaic community due to their high efficiency, low cost, and solution processability. Understanding the fundamentals of metal halide perovskite and its interfaces is extremely important for achieving high-quality materials and developing efficient devices using these materials with the necessary properties. Various methodologies have been used to evaluate the excellent optoelectronic properties, efficiency, and stability of PSCs [...] 4765 36500 |
Zeolite-Containing Catalysts in Alkylation ProcessesAbstract
This article provides an overview of zeolite-containing catalysts used in the alkylation of benzene and toluene with olefins, isobutane with butenes and butane-butene fractions, gasoline and oil fractions with olefins, propane-propylene, and butane-butylene fractions of catalytic cracking. Zeolites have various types of structures, including BEA, MFI, MWW, FAU, etc., which differ in pore size and the number and location of the channels. High-silica zeolites have a large pore volume, high acidity, good hydrothermal [...] 4744 24306 |
Exploration of Molybdenum Oxide Compounds-A Reviewby
Abstract
The evolution of nanomaterials has been critical in modifying materials at the nanoscale for specialized uses. Carbon nanotubes were initially viewed as promising for electronics, but their inability to discriminate between semiconducting and metallic phases led to the creation of quasi-two-dimensional (Q-2D) materials. Molybdenum nanoparticles are utilized as alloy additions in corrosive and high-vacuum environments. Their characteristics differ significantly from those of their bulk counterparts. This review anal [...] 4648 32045 |
Kinetic Modeling of the Esterification of Oleic Acid and Methanol in Conventional and Adsorptive Reaction SystemsAbstract
Biodiesel is derived from renewable vegetable or animal sources and is either used as a standalone fuel or blended with oil-based diesel. The kinetic mechanism of the esterification of oleic acid was investigated in a conventional batch reactor and a batch reactor coupled to a water adsorption system. The esterification was performed with oleic acid and methanol at different temperatures (70 to 110 °C) and alcohol-to-oleic acid molar ratios (3:1 to 9:1), using sulfuric acid as a catalyst. A kinetic model was constr [...] 4379 21045 |
Development of an Efficient Bi-Functional Catalyst made of a Novel Hybrid Material for Rechargeable Zn-Air BatteryAbstract
One-pot synthesis of mesoporous hybrid material consisting of Mn-Co/CoO nanoparticles encapsulated in an N-doped graphene shell decorated with Mo2C nanoparticles (Mo2C-NC@Mn-Co/CoO) was reported. The Mn and Mo components synergistically refined the graphitized carbons due to the interactions with N and C atoms while promoting the stability of the Co/CoO nanoparticles. These components exhibited a beneficial effect on the dispersion of the active metal/metal oxide nanoparticles and the formation of a mesoporous stru [...] 4355 16618 |
Microbial Cyclodextrin Glycosyltransferases: Sources, Production, and Application in Cyclodextrin SynthesisAbstract
Cyclodextrin glycosyltransferase (CGTase) is a multifunctional enzyme that hydrolyzes the α-glycosidic bond between two sugar molecules and synthesizes cyclodextrins (CDs) and other transglycosylation products. It is a ubiquitously present extracellular enzyme that offers the CGTase-producing organism the sole right onto starch substrates over other microbes. The present review provides a brief account of diversity among CGTase-producing microbes, CGTase production in different heterologous hosts (wherein ext [...] 3804 25872 |
Lipases: Sources of Acquisition, Ways of Production, and Recent Applicationsby
Abstract
Enzymes are extensively used in biotechnological processes in several areas of industry. They are sustainable and safe, and their specificity is another characteristic that improves the performance in the process. Among enzymes, lipase is relevant due to the ability to play different roles in the industry and the possibility of collecting them from microbial sources that are found in industrial residues. This can reduce the costs of enzyme production. In relation to that, lipase immobilization is an interesting pro [...] 3361 40289 |
One-Pot Tandem Synthesis of Nitriles and Amides from Biomass Platform CompoundsAbstract
In recent years, research on converting biomass platform compounds into high-value chemicals and pharmaceutical intermediates has garnered huge interest. Nitrile and amide groups are key structures in natural products and biologically active molecules. The direct conversion of biomass platform compounds into nitriles and amides will undoubtedly be an important guide for biomass utilization. In this paper, a facile and efficient triphosgene-assisted one-pot conversion for aldehydes and ketones into nitrile and amide [...] 3339 16308 |
Effect of Acid Treatment on the Properties of Zeolite Catalyst for Straight-Run Gasoline UpgradingAbstract
The objective of this research was to analyze the effect of different concentrations of nitric and hydrochloric acids on the structural, acidic, and catalytic properties of a post-synthetic treated ZSM-5 type zeolite at various temperatures. The properties of zeolite catalysts were determined using different methods, such as the Brunauer-Emmett-Teller (BET) method for specific surface area, temperature-programmed desorption (TPD) of ammonia method for acidic properties, and a flow-through unit with fixed bed cataly [...] 3292 17540 |
Hierarchical MFI Zeolite Catalysts: How to Determine Their Textural Properties?-A Comparative Studyby
Abstract
It is important to elucidate the role of the surface areas and pore volumes of hierarchical zeolites to understand their behavior as catalysts. Micro-and mesopore surface areas and volumes of the hierarchical MFI (Mobil Five zeolites) were assessed following several methods: (i) N2 adsorption at 77 K using classical and corrected t-plot analyses methods, (ii) pre-adsorption of n-nonane was followed by the study of the N2 adsorption at 77 K, and (iii) non-local-density functional theory (NLDFT) analysis using either [...] 2831 22884 |
Sustainable Synthesis of Zeolitic Imidazolate Framework-8 Nanoparticles and Application in the Adsorption of the Drug Chlorhexidineby
Abstract
In an attempt to synthesize nanomaterial concerning chemistry, the sustainable synthesis of Zeolitic Imidazolate Framework-8 (ZIF-8) nanoparticles by a low-cost approach through the recycling of waste mother liquors was explored and then indicated the potential to remove chlorhexidine (CHLX) from an aqueous solution. ZIF-8 was produced under solvothermal reaction at 25°C and characterized by Fourier Transform Infrared Spectroscopy, X-ray diffraction, adsorption/desorption of N2, dynamic light scattering and con [...] 2474 16806 |
Recent Development of Photocatalytic Application Towards Wastewater Treatmentby
Abstract
With increasing population levels and rapidly growing industries worldwide, the purification of water contaminated with different impurities is one of the biggest challenges we face in recent times. Photocatalysis holds great potential as an efficient mineralization process to remove the foreign matter present in wastewater. Rapid advancement in innovative materials development has made photocatalysis the frontrunner among different water treatment methods. Our main priority lies in different strategic approaches t [...] 2441 17685 |
Enhanced Photocatalytic Degradation of p-Nitrophenol and Phenol Red Through Synergistic Effects of a CeO2-TiO2 NanocompositeAbstract
Organic compounds are one of the most severe pollutants occurring in the environment. Hence, it is important to remove these compounds from the environment through remediation processes such as photocatalysis. The present study investigated the photocatalytic degradation of p-nitrophenol (NP) and phenol red (PR) using a cerium oxide-titanium oxide nanocomposite (CeO2-TiO2nc) under UV light. CeO2-TiO2nc was synthesized using the co-precipitation method. An X-ray diffraction (XRD) analysis confirmed the phase purity [...] 2388 11308 |
Catalytic Performance of CO:Ni Mixed Oxide Based Catalyst for Green Fuel Synthesis from Biomass Derived Citrullus Colocynthis OilAbstract
This study aimed to synthesize nickel oxide (NiO) and cobalt oxide (Co3O4) based catalysts for synthesizing biodiesel from Citrullus colocynthis oil. Cobalt-nickel mixed oxide catalysts made by co-precipitation technique with different Cobalt to Nickel ratios and named Co:Ni (50:50), Co:Ni (67:33), and Co:Ni (33:67). The Characterization of these synthesized catalysts was performed by XRD and SEM analysis. The transesterification process checked the catalytic activity of these catalysts, and it was found that Co:Ni [...] 2363 9437 |
Effect of ZSM-5 Particle Size and Framework Silica-to-Alumina Ratio on Hexane Aromatizationby
Abstract
Parent ZSM-5 and Ga-modified ZSM-5 catalysts with different Si/Al ratios and particle sizes were prepared. The physicochemical properties of the prepared catalysts were investigated by performing X-ray powder diffraction analysis, BET surface area analysis, and NH3-TPD analysis. The performance of the aromatization reaction of the prepared catalysts was evaluated with 1-hexane as a model compound. The zeolite catalysts with a low SiO2/Al2O3 ratio possessed better activity than those with a high SiO2/Al2O3 ratio. Ga [...] 2292 15135 |
Hydrocracking of Di-and Triaromatic Hydrocarbons to Monoaromatics over Mixed Bi-functional CatalystsAbstract
In this study, we present selective hydrocracking of poly (di and tri) aromatic compounds to monoaromatics, such as benzene, toluene, and xylenes (BTX), over a mixture of Pt/Al2O3 and Y zeolites. The polyaromatic compounds feed is a combined simulated model feed, which is similar to light cycle oil (LCO) in composition. The feed is processed in a fixed bed reactor over a catalyst mixture: in the first step, selective hydrogenation of di and tri-aromatic compounds occurs in the presence of Pt/Al2O3 catalyst, followe [...] 2285 12409 |
Design of Heterogeneous Catalysts for the Conversion of Furfural to C5 Derivatives: A Brief Reviewby
Abstract
Technological development made in the field of biomass application allows synthesizing several high-value products, such as furfuraldehyde. Furfural, produced through sequential hydrolysis and dehydration reactions from biomass, is considered a platform molecule and a precursor of several other chemicals and biofuels that are generated following reactions such as hydrogenation, hydrodeoxygenation, and decarboxylation. This review aims to reveal the environmental-friendly mechanisms followed for producing furfural d [...] 2283 14579 |
Enhancement of Fischer-Tropsch Synthesis by Periodical Draining of the Wax-Filled Pores of a Cobalt Catalyst by HydrogenolysisAbstract
Fischer-Tropsch reactors operated in a steady state suffer from a low pore effectiveness factor and a high methane selectivity caused by internal mass transfer limitations due to the accumulation of long-chain hydrocarbons inside the catalyst pores. Therefore, an alternating process switching between Fischer-Tropsch synthesis (FTS) and drainage of the pores by hydrogenolysis is proposed. The periodical cracking of the accumulated waxes within the (partially) filled pores, realized by a switch from syngas (H2, CO) t [...] 2242 15805 |
Perovskite Oxide Thermoelectric Module - A Way Forwardby
Abstract
In the era of renewable and sustainable energy, perovskite materials remain pioneers as energy harvesting materials, be it thermoelectric waste heat harvesting or photovoltaic solar cell application. Oxide perovskite material is an emerging thermoelectric material in solving energy shortage issues through waste heat recovery. The chemical and structural stabilities, oxidation resistance, and cost-effective and straightforward manufacturing process are a few advantages of the oxide-based thermoelectric materials. Th [...] 2141 11252 |
Synthesis of NaA Zeolite: Conventional Route and Green RouteAbstract
The research describes a sustainable approach for the synthesis of zeolite NaA using kaolin as an alternative source of silica. The main objective of this research was to prepare NaA zeolite using metakaolin derived from kaolin from the state of Rio Grande do Norte, Brazil, as an alternative source of silica, reducing the production cost and evaluating its thermal stability. In addition, a study of the thermal stability of the zeolite and cost estimates for zeolite production were carried out. Traditional methods o [...] 2127 12940 |
Fungal Laccase-Mediated Enhancement of the Bioactivity of Green Algae Extractsby
Abstract
Biomass derived from green marine macroalgae Ulva sp. is considered a rich source of bioactive compounds. In the present study, we demonstrate the increased bioactivity of a phenolic-rich extract derived from green marine macroalgae Ulva intestinalis after its treatment with fungal laccases from Trametes versicolor and Agaricus bisporus. The phenolic composition of the extract, before and after its enzymatic treatment, was determined through several analytical methods. Furthermore, the antioxidant, enzyme-inhibitor [...] 2104 12070 |
Photocatalytic Degradation of Azo Dyes Using Microreactors: Mechanistic Study of its Effects on H2O2 AdditionAbstract
The photocatalytic reaction involved in TiO2 photocatalysis was investigated using a microreactor coated with TiO2 film on the glass plate attached on one side of the microreactor. It was confirmed that the effect of H2O2 on the photocatalytic degradation efficiency of azo dyes (acid orange 7, acid red 151, and acid yellow 23) was dependent on the polymorphs (anatase and rutile) of TiO2 coated on the glass plate of the UV-irradiated microreactor. Scavengers of holes (KI) and electrons (p-benzoquinone) were added to [...] 2074 12689 |
Thermokinetic and Thermodynamic Parameters for Catalytic Pyrolysis of Medium Density Fiber over Ni/Beta Zeoliteby
Abstract
Catalytic pyrolysis is an attractive alternative for converting biomass into energy and chemicals to replace fossil sources. This has encouraged the search for efficient catalysts that can directly remove oxygenated products during pyrolysis, since they are the main problem in the processing and use of the products obtained. The catalytic and non-catalytic pyrolysis of medium density fiber (MDF) over beta zeolite-supported nickel (3 and 5%) was performed using the biomass/catalyst of 1.0/0.2 ratio. The thermokineti [...] 1995 10760 |
Nano Metal Oxide Frameworks (NOF): Development of New Heterogeneous Catalyst for the Synthesis of Furan Derivatives from GlucoseAbstract
A surface modification approach has prepared a nanostructured organic framework connecting two metal oxide NPs. The surface modifier attached two metal oxide NPs via molecular interaction to generate modular structures of fiber, rod, or sponge materials. Thus, obtained hybrid systems have been confirmed through FT-IR, TGA, PXRD, and SEM. Metal oxides such as Fe3O4 and MgO generated mixed materials via the surface modification approach. Thus, obtained materials have been successfully used to dehydrate biomass-derive [...] 1990 8925 |
The Effect of SnO2 and Rh on Pt Nanowire Catalysts for Ethanol OxidationAbstract
In this study, we synthesized Pt-Rh nanowires (NWs) through chemical reduction of metallic precursors using formic acid at room temperature, excluding the use of surfactants, templates, or stabilizing agents. These NWs were supported on two substrates: carbon (Vulcan XC-72R) and carbon modified with tin oxide (SnO2) via the sol-gel method (10 wt.% SnO2). We explored the electroactivity of Pt/SnO2/C, Pt-Rh/C, Pt-Rh/SnO2(commercial)/C (commercial SnO2), and Pt-Rh/SnO2/C NWs toward electrochemical oxidation of ethanol [...] 1982 14293 |
Controllable Cyclopalladated Polythiophene Imine Monolayer by Self-Assembly, Hybrid Doping and Electrochemical Polymerization: A Simple Way to Enhance Activity and StabilityAbstract
In this article, an approach to generate self-assembly cyclopalladated polythiophene imine monolayers (denoted as ITO@Pd-CPTIMs) is described. The monolayers were fabricated by combining self-assembly (SA), hybrid doping (HD), and electrochemical polymerization (ECP) called SA-HD-ECP. The catalytic activity and stability of the polymerized monolayers in the Suzuki coupling reaction were improved by modulating the structure and morphology in hybrid doping using different thiophene derivatives, concentrations, and sc [...] 1964 10592 |
In Water High Yield and Selectivity of CH4 and H2 Production from CO2 Using UVC Light and a SiO2-surface-modified TiO2 Photocatalystsby
Abstract
To improve CH4 and H2 formation from CO2 photoreduction using non-organic, non-laborious, and inexpensive photocatalysts, we have prepared two surface-silicate-modified TiO2 catalysts: P25-SiO2 and AmTiO2-SiO2 (amorphous TiO2) to be tested in water and using UV light. The last catalyst produces more CH4 and H2 in water than P25 (3:1 TiO2 anatase: rutile) under UV light irradiation of HCO3- and CO2; am-TiO2-SiO2 at pH = 7, produces 8 times more CH4 and H2 than P25 with selectivity at the reactor headspace of 30% and [...] 1960 9072 |
Morpholine-Based Novel Ionic Liquid for Synthesis and Characterization of Triazolidinethiones and Their Biological Propertiesby
Abstract
Keeping the green chemistry approach in mind we have synthesized a novel morpholine-based ionic liquid [NBMMorph]+Br-. The structure of Ionic liquid was confirmed by spectral techniques viz. IR, 1H NMR, and 13C NMR, analysis. The synthesized novel IL [NBMMorph]+Br- was utilized to prepare 1,2,4-triazolidine-3-thiones of biological significance. The [NBMMorph]+Br- IL shows excellent catalytic activity, and a simple filtration technique can separate the thiazolidinedione products. The structure of the synthesized com [...] 1944 11393 |
NaY Zeolite Synthesis from Vermiculite and Modification with SurfactantAbstract
This work focuses on preparing NaY zeolite using alternative sources of silica and modifying the zeolite with the surfactant cetyltrimethylammonium bromide. Two different hydrothermal synthesis routes were employed: the conventional method using sodium silicate as the silica source, and the other is a sustainable approach using vermiculite clay as the silica source. In traditional zeolite synthesis, sodium silicate is often used as the source of silica. However, . The vermiculite was subjected to an acid treatment, [...] 1940 10752 |
Enhancing Kerosene Selectivity of Fischer-Tropsch Synthesis by Periodical Pore Drainage Via Hydrogenolysisby
Abstract
Accumulation of wax inside the catalyst pores during transient cobalt-catalyzed Fischer-Tropsch synthesis (FTS) leads to unfavorable product distribution and low activity by imposing internal mass transfer limitations. The condensation of paraffin severely changes the apparent product stream that actually leaves the reactor before the catalyst pores are filled completely and the steady state is reached. Thus, the product distribution of the transient FTS is less complex than expected in comparison to the steady-sta [...] 1936 13829 |
Recent Advances in the Application of Perovskite Catalysts in the Dry Reforming of MethaneAbstract
The use of the dry reforming of methane (DRM) to convert the two principal greenhouse gases, methane and carbon dioxide, to syngas (a mixture of H2 and CO) has attracted increasing attention in recent years. However, the DRM reaction suffers from the twin disadvantages of carbon deposition and sintering, so a highly efficient and robust catalyst with superior anti-deactivation properties is required. One way to meet this need is to incorporate active metals into crystalline oxides, such as perovskite. In this paper [...] 1919 14274 |
Spectrophotometric and Spectrofluorimetric Quantification of Urea via Silver Nanoparticles Prepared by Wet Chemical MethodAbstract
Silver nanoparticles have been utilized in an easy, sensitive, and effective approach through spectrophotometry and spectrofluorimetry to quantify urea in water samples. Here, 1,3-di-(1H-imidazole-1-yl) -2-propanol (DIPO) was employed to stabilize Ag NPs produced from the reduction of aqueous silver nitrate by sodium borohydride (NaBH4). Beer-Lambert's law was applied for determination using the complexation of Ag NPs with urea molecules. The results show urea can be assessed concurrently with good results and perc [...] 1895 14132 |
Synthesis and Characterization of MCM-41 Nanomaterials Containing Titanium and Application for Catalytic Oxidation of BTEXby
Abstract
The TiO2/MCM-41 nanomaterials were synthesized by impregnation with an excess solvent with different percentages of titanium dioxide. They were used for catalytic degradation of Benzene Toluene Ethylbenzene and Xylenes (BTEX) in the presence of hydrogen peroxide in aqueous media. The obtained materials were characterized by X-ray Diffraction, nitrogen adsorption-desorption using the BET method and Fourier Transform Infrared Spectroscopy. The nanostructured phase of the hexagonal ordered materials was obtained even [...] 1843 10579 |
Ethanol Oxidation on Gold Nanowire Containing Oxygen Impurities: A Study by Ab Initio Molecular Dynamics SimulationsAbstract
Linear atomic chain (LAC) gold nanowires (Au-NWs) containing oxygen impurities are materials that could be used as supports to stimulate chemical reactions. Its peculiar structural characteristics, such as abnormal Au-Au bonds, make it interesting to explore the chemical reactions of this material at a theoretical level. This work investigated the chemical reaction of ethanol supported on Au-NW containing two oxygen impurities. Using ab initio molecular dynamics simulations, it was shown that the presence of oxygen [...] 1842 8773 |
3D Fe3O4-decorated Nitrogen-doped Graphene Aerogel as a Highly Durable Electrocatalyst for Oxygen Reduction ReactionsAbstract
The rational design of efficient electrocatalysts for oxygen reduction reaction (ORR) is the key to developing fuel cells and metal-air batteries. Carbon-supported iron-based materials, as the most promising electrocatalysts for ORR, have drawn much attention as they are cost-effective and exhibit high activity. In this work, a three-dimensional (3D) Fe3O4-decorated N-doped graphene aerogel (Fe3O4/NGA) catalyst was synthesized following a simple hydrothermal method which was followed by an annealing process. The co [...] 1837 10646 |
Fischer-Tropsch Synthesis on Co/SBA-15 Catalyst: Characterization and Oligomerization Modelingby
Abstract
In this study, we investigated the oligomerization mechanism of the Fischer-Tropsch synthesis catalyzed by a cobalt-based catalyst supported by SBA-15. The Co/SBA-15 catalyst contained 20% w/w of cobalt. It was prepared by the wet impregnation method and characterized by X-ray diffraction (XRD), N2 adsorption-desorption, temperature-programmed reduction (TPR), and scanning electron microscopy coupled to X-ray energy dispersion spectroscopy (SEM-EDS). The FT synthesis was conducted in a slurry bed reactor operating [...] 1836 9214 |
Recent Progress in the Development of Molecular Electrocatalysts for Formate Oxidationby
Abstract
Fuel cells based on renewable synthetic fuels are promising alternatives to fossil fuel combustion for efficient electricity production. Much focus has been placed on hydrogen as a chemical fuel, but being a flammable gas, there are challenges with its safe handling. Formic acid is an attractive liquid fuel for use in direct formic acid or formate fuel cells, and it can in principle be produced from the thermal or electrochemical reduction of carbon dioxide. Over the past ten years, advances have been made in the d [...] 1834 12357 |
Pd-Ni-B/C Nanocatalysts for Electrochemical Oxidation of Ethanol in Alkaline Mediaby
Abstract
This paper describes the synthesis of Pd0.70-Nix-By nanoparticles (x:y = 0.30:0, 0:0.30, 0.25:0.05, 0.20:0.10, 0.15:0.15, and 0.10:0.20) supported on carbon Vulcan XC-72 R by the chemical reduction method using ethylene glycol as a reducing agent for the study of the electrochemical oxidation of ethanol in alkaline media. Neither surfactants nor templates were used during the syntheses. The catalysts were physically characterized by transmission electron microscopy that showed the formation of nanoparticles with di [...] 1824 10981 |
Pd-Cu Bimetallic Based Catalysts for Nitrate Remediation in Water: Synthesis, Characterization, and the Influence of Supportsby
Abstract
The use of Pd-Cu bimetallic catalysts in the reduction of aqueous nitrate ions by hydrogen was studied. The catalysts were supported on multi-walled carbon nanotubes (MWCNTs), activated carbon (AC), and Titania, and the influence of the support on the nitrate reduction activity in water was then investigated. The catalysts were characterized before and after use by FT-IR, XRD, SEM, EDX, and Laser Granulometry. It was found that the surface characteristics of the support have an influence on the catalyst activity, w [...] 1780 12601 |
A New Chiral Cyclopalladated Ferrocenylimine Self-assembly Polymeric Film supported on Silicon for Heck and Suzuki-coupling ReactionsAbstract
A new chiral cyclopalladated ferrocenyl imine catalyst (called 4a2) was designed and synthesized, and its self-assembly catalytic polymeric brush supported on silicon (denoted as Si@PB4a2) was also fabricated by surface-initiated atom transfer radical polymerization (ATRP) and characterized. The catalytic properties of monomer 4a2 in homogeneous and Si@PB4a2 in heterogeneous in Heck and Suzuki cross-coupling were investigated, respectively. They exhibited higher catalytic activity in Heck, and Suzuki coupling react [...] 1776 9240 |
Enzymatic Hydrolysis of Meat Waste for a Circular Economyby
Abstract
This work demonstrates the possibility of implementing a technology that allows profitable value to be drawn from the meat waste from retail stores. Protein hydrolysate, collagen and fatty acids were recovered from meat waste through enzymatic hydrolysis using a mixture of enzymes: a protease (Alcalase) and a lipase (Resinase). Enzymatic hydrolysis was studied by response surface methodology (RMS). Four independent variables were used to study the response variables. The analysis showed that all factors including p [...] 1754 11468 |
Enzymes in Poly(Butylene-Succinate) Industry: An Overview on Synthesis Routes and Post-Processing Strategiesby
Abstract
This paper will present some sectors in which enzymes can replace traditional catalysts in poly(butylene-succinate) industry, emphasizing the green chemistry aspects associated with these newer strategies. 1747 13673 |
Preparation of a Novel Bi2MoO6/Ag/Ag2CrO4 Catalyst with Promoted Visible Light Photodegradation of RhB DyeAbstract
A series of novel Bi2MoO6/Ag/Ag2CrO4 heterostructure photocatalysts (denoted as BA-X, X = 1, 3, 5, 10) were synthesized using a coprecipitation method. These photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) and their photocatalytic properties were investigated. Compared with pure Bi2MoO6 or Ag2CrO4, BA-5 exhibited a higher photocatalytic property and broader light absorption. In addition, the surface pla [...] 1745 11684 |
Effect of Different Additives on the Structure and Activity of β-Galactosidase Immobilized on a Concanavalin A–Modified Silica-Coated Titanium Dioxide Nanocompositeby
Abstract
Interpreting the relationship between the activity and structure of β-galactosidase is necessary to perceive the impact of the enzyme’s conformation on its catalysis. The current study thoroughly explains the effects of additives such as ethylenediaminetetraacetic acid (EDTA), sodium dodecyl sulfate (SDS), dithiothreitol (DTT), and urea on β-galactosidase activity and structure. β-Galactosidase activity was determined at various ionic strengths and temperatures as a function of time. Structural [...] 1734 9899 |
Synthesis of SAPO-34 Zeolite Membrane: Influence of Sources of SilicaAbstract
The research described the production and characterization of various materials, particularly alpha-alumina ceramic supports, zeolite SAPO-34, and zeolite membranes. Ceramic supports were manufactured through dry uniaxial compaction. Sintering of the supports was carried out at 1300°C for 2 h. SAPO-34 zeolites and zeolite membranes were synthesized through a hydrothermal process involving two steps: a first step at 38°C for 24 h and a second step at 200°C for 24 h. The research aimed to determine how different sili [...] 1721 11810 |
Leaf Mediated Curcuma sp. Silver Nanoparticles as Catalyst - Evaluating Their Antioxidant, Cytotoxicity, Para-Nitrophenol Catalytic and Photocatalytic ActivityAbstract
Nanotechnology is a fast-rising market in catalytic research; however, the production of eco-friendly nanoparticles remains a significant challenge. In this study, silver nanoparticles (AgNPs) were synthesized from the agro-industrial waste of leaves of C. longa, C. aromatica, C. caesia, C. zedoaria, and C. amada at RT after 24 h, which was confirmed with UV-spectrophotometric evaluation between 320-520 nm. SEM revealed cubic and 30-50 nm AgNPs, while band-gap energy was presented as semi-conductors. Synthesized Ag [...] 1715 19896 |
Short Hydroacylation-Based Synthesis of Four Aryl-3-hydroxypropanones, Predictable Biomass-Derived C9 Platform MoleculesAbstract
A two-step protocol for the synthesis of aryl-3-hydroxypropanones, which were regarded as lignin degradation products, was proposed herein. This protocol provided a more rapid and easier access to aryl-3-hydroxypropanones, and aryl-3-hydroxypropanones were expected to be ideal platform molecules for the synthesis of more complex value-added targets. 1715 8731 |
Adsorption of Rhodamine-B (RhB) and Regeneration of MCM-41 Mesoporous Silicaby
Abstract
Rhodamine (RhB) adsorption was carried out on MCM-41 and MCM-41 calcined. The effect of parameters such as pH was investigated. The reusability potential of MCM-41 was also established and the mechanism of RhB adsorption was discussed. MCM-41 was synthesized and calcined, with all samples characterized by X-Ray Diffractometry, X-ray Fluorescence by Dispersive Energy, Infrared Spectroscopy, Scanning Electron Microscopy, and Thermogravimetric analysis. The results of the characterization techniques performed confirme [...] 1647 11820 |
Versatility of Supported Gold Nanoparticles on Hydrotalcites used for Oxidation and Reduction Reactionsby
Abstract
Regardless of their size, supported gold nanoparticles are largely used for liquid-phase oxidation reactions. Small gold nanoparticles exhibit good performance during the reduction of organic compounds. The direct reduction of carboxylic acid to aldehyde is a famous and familiar reaction in the field of organic chemistry and is considered as one of the fundamental chemical transformations. Herein, we present Au/hydrotalcite, Au/MgO, and Au/Al2O3 systems as heterogeneous versatile catalysts to realize the oxidation [...] 1645 11025 |
Impact of Pt-Ni Nanoparticle Architecture on Electrocatalytic Oxidation Reaction in Fuel Cellsby
Abstract
This paper investigates how the aggregation of bimetallic nanoparticles (NPs) influences the electronic condition of the surface adsorption site and, hence, the performance of materials during the electrooxidation of fuels in an alkaline medium. First, we synthesized Pt-Ni NPs in three configurations: ordered intermetallic, ordinary alloy, and core-shell. The NPs contained Pt and Ni close to a 1:1 Pt/Ni atomic ratio. They had similar particle sizes, which allowed us to evaluate their performance without the influen [...] 1635 8463 |
Cost-Effective Biodiesel Synthesis from Waste Marble Powder as A Green Heterogeneous Catalyst Using Pongamia Pinnata Oilby
Abstract
Waste marble powder (WMP) is Investigated for developing heterogeneous catalysts by calcination method and used in biodiesel synthesis by esterification-transesterification process from Pongamia Pinnata oil. Hammet indicators, Fourier transform infrared (FT-IR), Thermogravimetric analysis, and X-ray powder diffraction (XRD) techniques were also studied for the characterization of developed catalyst from waste marble powder (WMP). The conversion of calcium carbonate to calcium oxide in marble powder was found at 800 [...] 1635 10215 |
Effect of Microwave Radiation on the Development of a Porous Aluminum Carrier of the Active Mass of Catalysts in Heterogeneous Catalytic ReactionsAbstract
In this study, we prepared a fine-grained, aluminum-reinforced alumina support matrix of the active mass of catalysts, which showed activity in heterogeneous catalytic reactions stimulated by electromagnetic radiation in the microwave range. The support absorbed microwave radiation of 2.45 GHz. We compared the textural characteristics of samples of Al/Al2O3 supports obtained by conventional heat treatment to those synthesized by heat treatment in a microwave field. We found several advantages of heat treating poten [...] 1635 7396 |
Kinetic Model for the Hydrolysis of Olive Oil by Lipase in Absence of EmulsifierAbstract
Lipase-catalyzed hydrolysis of olive oil has been studied in the absence of emulsifier. A simple mathematical model to predict the hydrolysis rate is derived from a proposed kinetic mechanism of the reaction. The hydrolytic reaction obeys Michaelis-Menten kinetics with a simultaneous second-order enzyme deactivation. The model predictions closely agree with the experimental results. 1616 9742 |
The Use of Composite TiO2/Activated Carbon Fibers as a Photocatalyst in a Sequential Adsorption/Photocatalysis Process for the Elimination of CiprofloxacinAbstract
This work reports the performance of a sequential adsorption/photocatalysis process using activated carbon fibers with deposited TiO2 for the elimination of the antibiotic ciprofloxacin (CIP) in water. A commercial activated carbon fiber (ACF10) was selected as the support, and a TiO2 coating was synthesized using Metal Organic Chemical Vapor Deposition (MOCVD). Experiments were carried out using a photocatalytic reactor irradiated with monochromatic LEDs (365nm). Two different processes have been studied: adsorpti [...] 1615 11250 |
Determining the Band Alignment at the BiVO4|NiOOH Interface Using the Hybrid DFT TechniqueAbstract
It is important to understand the band offsets between semiconductors, which are crucial to determine the direction of electron transfer at the interfaces. Two methods are normally used to determine the direction from the first principles: alternating slabs put in contact (without empty spaces between them) and separate calculations for each material surface in the presence of vacuum spaces. The first method may introduce distortions due to insufficient epitaxial match, which may lead to bandgap changes, and the se [...] 1610 9882 |
Nb2O5: Percentage Effect of T/H Phase and Evaluation of Catalytic Activity, a Preliminary Studyby
Abstract
Due to its similar characteristics to titanium, niobium has become an attractive alternative in photocatalytic processes. Research indicates that titania has an optimal percentage of phases resulting in a commercial catalyst, P25, that contains more than 70% anatase with a minor amount of rutile and a small amount of amorphous phase. On the other hand, for Nb2O5, percentage optimization was little explored in the literature, which consists of studying the phases obtained via heat treatment individually and in diffe [...] 1607 8159 |
Dearomatization of the Kerosene Fraction: Kinetic StudiesAbstract
The kinetics of dearomatization of a kerosene fraction processed using a zeolite catalyst (0.9 HZSM-5) at different temperatures (160-200°C), the molar ratio between the aromatic hydrocarbons present in the kerosene fraction and n-decene (1:(0.5-4)), and the reaction time (1-3 h) were studied. Based on the obtained data, a kinetic model for kerosene dearomatization is proposed. It is assumed that the single-center Riedel mechanism is followed. The stage associated with the interaction between n-decene adsorbed on t [...] 1599 9156 |
Acetonitrile Combustion over Copper-Based Nanocatalysts: A Structure-Performance Relationship StudyAbstract
In this paper, the relationship between activity and structure of Cu2+ in different chemical environments of Cu-BETA, La2CuO4, and CuO nanocatalysts was systematically investigated for acetonitrile combustion. The study revealed that exchanged and octahedral species of Cu2+ coexist in Cu-BETA, while octahedral species are dominant in CuO and La2CuO4. All nanocatalysts achieved high conversion rates of acetonitrile, which rapidly increased with temperature. CuO and La2CuO4 led to the formation of undesired products [...] 1595 9815 |
Zn(OCOCH3)2·2H2O Catalysed Efficient Preparation of 2-Phenyl-4-Arylmethylidene-5-Oxazolinones under Ultrasonic ConditionAbstract
2-Phenyl-4-arylmethylidene-5-oxazolinones were synthesized in very high yield by subjecting a mixture of an aryl aldehyde/heterocyclic aldehyde/cinnamaldehyde and hippuric acid in anhydrous acetic anhydride and catalytic Zn(OCOCH3)2·2H2O to ultrasonication at 35 KHz for 4 to 8 min. This method has many advantages: use of a green catalyst; yields are high, involves easy workup procedure, is energy efficient and economically feasible. 1595 8448 |
Heterologous Expression, Characterization, and Comparison of Laccases from the White Rot Causing Basidiomycete Cerrena Unicolorby
Abstract
Lignin is the most abundant renewable source of aromatics on earth, and conversion of it to chemicals and fuels is needed to build an economically viable renewable biofuels industry. Biological routes to converting lignin to fuels and chemicals involve depolymerizing lignin using lignin-degrading enzymes that catalyze the breaking of ether and carbon-carbon bonds in the phenolic and non-phenolic subunits of lignin. Laccases are a crucial class of lignin-degrading enzymes and are copper-containing enzymes capable of [...] 1590 9216 |
Visible-Light-Induced Formation of Aromatic Ketones: A Metal-Free C−H Oxygenation Process in Air under Room TemperatureAbstract
The process of light-induced C-H oxygenation is of high interest as it can be used for the construction of oxygenated compounds. Herein, we report a mild and general method for the efficient synthesis of aromatic ketones following the process of metal-free C-H oxygenation. With air as the oxidant, high functional tolerance was demonstrated, and the desired ketones were obtained in moderate to excellent yields at room temperature (25 oC). Mechanistic studies suggested that the oxidative transformation potentially oc [...] 1588 10771 |
Biochemical Characteristics and Healing Activity of Bromelia laciniosa Leaf Proteaseby
Abstract
Macambira plant (Bromelia laciniosa Mart. Ex Shult. & Schult. f.) is a species belonging to the family Bromeliaceae, which is distributed widely in the hinterlands of northeastern Brazil, from Bahia to Piauí states. The plants of this species contain an enzyme complex named bromelain, which has great potential for therapeutic applications. In the present study, bromelain derived from Bromelia laciniosa leaves was assessed for its thermodynamic properties and in vitro cytotoxic and healing activities. Bro [...] 1579 12435 |
Iron Doped Titania/Polyaniline Composite: An Efficient Electrocatalyst for Hydrogen Evolution Reaction in Acidic MediumAbstract
The development of noble metal-free catalyst for hydrogen evolution reaction (HER) is the primary challenge in fuel production to replace fossil fuels. Here, we have synthesized Fe-doped TiO2/PANI nanocomposite via facile in situ polymerization method and studied its electrocatalytic activity towards HER. The composite catalyzes HER efficiently with an overpotential value of -180 mV vs. RHE in 0.5 M H2SO4 solution to achieve the current density of 10 mA cm-2 and also possesses unique stability of 8 h. However, a un [...] 1578 9280 |
Homogeneous {Ti2Ni} Heterotrinuclear Catalyst for Ethylene Polymerization and Copolymerizationby
Abstract
We synthesized and spectroscopically characterized a new heterotrimetallic {Ti2Ni} ethylene (co)polymerization precatalyst containing one (α-diimine)NiBr2 and two (phenoxy-imine)TiCl4 scaffolds. Its calculated structure was investigated at the DFT B3LYP/LACVP** level. Our calculations showed that the titanium(IV) centers were in a slightly distorted trigonal bipyramidal environment, and the average Ti···Ni distance was 8.76 Å. The precatalyst was used for synthesizing polyethylene a [...] 1559 11021 |
Degradation of Amido Black Dye Using Ultra-Violet Light Catalyzed by Iron Oxide Nanoparticles: Kinetics and Mechanism of Degradationby
Abstract
In this study, we investigated the degradation of amido black dye in an aqueous solution using ultra-violet (UV) light catalyzed by iron oxide nanoparticles (nano-Fe). The nano-Fe was synthesized by sodium borohydride reduction of ferric chloride solution and was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence spectrophotometry (XRF). The SEM of the nano-Fe showed regular spherical particles, the XRD examination showed a weak and broad peak at Fe (1 1 0), and the [...] 1553 8982 |
llmenite and Biomass Composite Nanomaterials - A Reviewby
Abstract
Ilmenite is a mineral whose crystallinity can be altered by chemical treatment, producing TiO2 and iron and titanium-based metal nanocomposites, which are applicable mainly for photocatalysis. Porous and crystalline biomass-derived carbon materials include graphene oxide, reduced graphene oxide, graphitic carbon nitride, catalytically graphitized sucrose and chitosan, and activated carbon. Ilmenite-based metal oxides coupled with biomass-based carbon materials are effective in environmental remediation, especially [...] 1533 9029 |
3D Printed Polylactic Acid (PLA) Well Plates for Enzyme Inhibition Studies: The Case of Pancreatic Lipaseby
Abstract
3D printed PLA has already been demonstrated for several biotechnological applications, including enzymes immobilization. The prerequisites for an efficient screening assay include using small volumes of reagents, low cost, and rapid screening of large numbers of compounds and extracts. Hence, assays based on microtiter plates are predominant. Thus, designing and fabricating scaffolds on a similar scale, which could serve as immobilization carriers, and their recruitment in inhibitors screening studies is of great [...] 1528 9219 |
Biocatalyzed Hydrolysis of Residual Oils and Proteins from Flax and Camelina Oilseed Press Cakes Using Lipase and ProteaseAbstract
In this study, a PoC (Proof of Concept) of a possible biomass valorization of flax and camelina oilseed press cakes was presented. Biocatalyzed hydrolysis of residual oils and proteins extracted from these wastes was studied. The biotransformation of oils was performed using commercial immobilized lipases, including Amano PS, Amano AK, and Candida Antarctica Lipase B (CALB). Acylglycerols were partially or fully hydrolyzed using Amano PS and AK. Triglycerides were not hydrolyzed by CALB, which behaved differently. [...] 1473 7726 |
Co2+ Doping and Molecular Adsorption Behavior of Anatase TiO2 (001) Crystal PlaneAbstract
TiO2 (001) crystal plane exhibits molecular adsorption and photocatalytic activity. The loading capacity of reactive oxygen species present on crystal planes helps in the significant improvement of catalytic activity. The methods of synthesis and conditions of existence significantly affect the molecular adsorption properties of crystal planes, which in turn affects the ability of the system to load reactive oxygen species. Herein, we report the simulation of the molecular adsorption behavior on the TiO2 (001) usin [...] 1446 9449 |
Stability of a Fe-Rich Cathode Catalyst in an Anion Exchange Membrane Fuel Cellby
Abstract
Fe-rich alloys have been widely studied as catalyst materials for the cathodic oxygen reduction reaction (ORR) in hydrogen fuel cells, and many have shown high activities. The stability of Fe-rich catalysts has also been researched, and some studies have shown promising results using an accelerated stress test (AST), which uses a potential cycling method. However, for commercial fuel cell applications, such as standby power systems, the catalyst has to tolerate a high potential for a long period, which can not be r [...] 1440 10894 |
Lignocellulosic Biomass and Enzymes: Fundamentals, Emerging Technologies, and ApplicationsAbstract
Lignocelluloses are complex plant polysaccharides made of lignin, cellulose, and hemicellulose, and products made from these components find immense market potential. They can be effectively valorized to products related to bioenergy, bioplastics, food and nutrition, medication delivery systems, and other elements. Significant sources of lignocellulosic biomass include sugarcane bagasse, corn cob, rice straw, potato haulms, cocoa pods, etc. Enzyme-based valorization processes find immense potential, as they are eco [...] 1439 11000 |
A Remarkable Pt Doped CNT Catalyst as a Double Functional Material: Its Application for Hydrogen Production and SupercapacitorAbstract
In this study, by producing bifunctional material, hydrolysis, and supercapacitor applications were investigated. The carbon nanotube-supported Pt catalyst was prepared using the sodium borohydride (NaBH4) reduction. Surface characterization of the synthesized Pt/CNT catalyst was performed using scanning electron microscopy-energy dıstrıbutıon X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Hydrolysis experiments were performed after deciding on the appropriate ato [...] 1426 7479 |
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