Iron Nitrate Salts Research Articles

Metal-Nitrate-Catalyzed Levulinic Acid Esterification with Alkyl Alcohols: A Simple Route to Produce Bioadditives

This work developed an efficient route to produce fuel bioadditive alkyl levulinates. Special attention was paid to butyl levulinate, which is a bioadditive with an adequate carbon chain size to be blended with liquid fuels such as diesel or gasoline. In this process, levulinic acid was esterified with butyl alcohol using cheap and commercially affordable metal nitrates as catalysts, producing bioadditives at more competitive costs. Iron (III) nitrate was the most active and selective catalyst toward butyl levulinate among the salts evaluated. In solvent-free conditions, with a low molar ratio and catalyst load (1:6 acid to alcohol, 3 mol% of Fe (NO3)3), conversion and selectivity greater than 90% after an 8 h reaction was achieved. A comparison of the iron (III) nitrate with other metal salts demonstrated that its superior performance can be assigned to the highest Lewis acidity of Fe3+ cations. Measurements of pH allow the conclusion that a cation with high Lewis acidity led to a greater H+ release, which results in a higher conversion. Butyl levulinate and pseudobuty levulinate were always the primary and secondary products, respectively. The consecutive character of reactions between butyl alcohol and levulinic acid (formation of the pseudobutyl levulinate and its conversion to butyl levulinate) was verified by assessing the reactions at different temperatures and conversion rates. A variation in Fe(NO3)3 catalyst load impacted the conversion much more than reaction selectivity. The same effect was verified when the reactions were carried out at different temperatures. The reactivity of alcohols with different structures depended more on steric hindrance on the hydroxyl group than the size of the carbon chain. A positive aspect of this work is the use of a commercial iron nitrate salt as the catalyst, which has advantages over traditional mineral acids such as sulfuric and hydrochloric acids. This solid catalyst is not corrosive and avoids neutralization steps after reactions, minimizing the generation of residues and effluents.

Synergistic Ti-Fe Oxides on Fishbone-Derived Carbon Sulfonate: Enhanced Styrene Oxidation Catalysis

Fishbone-derived carbon sulfonate, modified through incipient wetness impregnation with titanium tetraisopropoxide and iron nitrate salts, displays catalytic activity in the oxidation of styrene with hydrogen peroxide (H2O2) as an oxidant. This was done to develop a cost-effective, non-toxic, and environmentally friendly bimetallic oxide catalyst, incorporating titanium and iron oxides on mesoporous-derived carbon fishbone to enhance styrene conversion and benzaldehyde selectivity in styrene oxidation using aqueous H2O2. The catalyst, featuring a combination of titanium and iron oxides on the surface of the fishbone-derived carbon sulfonate, demonstrates higher catalytic activity than single oxide catalysts, such as titanium or iron oxides alone. Factors influencing the catalyst's performance are investigated by using FTIR, XRD, XRF, SEM, and BET surface area. The results reveal that the presence of both titanium and iron oxides on the surface of the fishbone-derived carbon sulfonate and the catalyst's surface area creates a synergistic effect, the primary factors affecting its catalytic activity in styrene oxidation using H2O2 as an oxidant.

Green Medicine: A Novel Preparation Method for Green Synthesizing of Iron Nanoparticles Derived from Beta Vulgaris Extract.

This study aimed to synthesize new iron nanoparticles (FeNPs) using Beta Vulgaris (beet) extract as a reducing agent and test its bioactivity against Pseudomonas aeruginosa. In total, five grams of beet were ground and dissolved in 50 ml of distilled water and filtered with filter paper. The filtrate was then isolated. Different concentrations, including 25%, 50%, 100%, and 150% of the isolated filtrated substances were prepared from the stock solution. FeNPs were prepared from 0.5 moles of iron nitrate salt (Fe(NO3)3.9H2O which was mixed with the aqueous solution of beet extract. Moreover, two aqueous solutions were mixed thoroughly with continuous stirring at 60°C. The FeNPs were isolated, separated, identified, and characterized using different physicochemical techniques (i.e., X-Ray Diffraction, Ultraviolet-visible Spectroscopy, and Atomic Force Microscope). Subsequently, the bioactivity of the NPs against P. aeruginosa was tested. The Vitek antibiotic test for P. aeruginosa showed resistant activity against Piperacillin/Tazobactam, Cefazolin, Ceftazidime, Cefepime, Imipenem, Cefepime, Ceftazidime, Cefazolin, and Piperacillin/Tazobactam; in addition, it revealed high sensitivity toward Tobramycin, Levofloxacin, Trimethoprim, Gentamicin, Nitrofurantoin, and Ciprofloxacin. The FeNPs at 50% concentration showed the best inhibition activity against P. aeruginosa. In the current study, novel FeNPs were synthesized which showed activity toward P. aeruginosa that could be used to replace certain antibiotics as a green medicine.

Phase transformation in Fe2O3 nanoparticles: Electrical properties with local electronic structure

Present work is focused on the study of various physical properties of different phases (α & γ) of Fe2O3 prepared just by varying initial precursors and solvents. Diverse structural and spectroscopic techniques infer growth of α-phase using gelatin (GEL) + deionized water (DI) while mixed (α & γ)phase is obtained with GEL + ethylene glycol (EG) as precursor and solvents in iron nitrate salt. By controlling the properties of the solvent media, we have been able to tune the crystallite size from 26.31 nm (α-phase) to 38.87 nm (mixed-phase). The corresponding activation energy for α-phase and mixed-phase was calculated using the Arrhenius plot. Dielectric loss and permittivity in both samples exhibited different behaviour with temperature and which can be explained based on their electronic structure studied by the X-ray absorption spectroscopy technique. The interplay of different phases of materials can be achieved just by controlling the synthesis parameters like solvents/precursors or both.

Coal fly ash‐derived mesoporous SBA‐15 as support material for production of liquid hydrocarbon through Fischer–Tropsch route

AbstractThe supernatant solution of silicate species extracted from coal fly ash (CFA) by NaOH fusion is used under acidic conditions with surfactant pluronic P‐123 to prepare the mesoporous silica (SBA‐15). Structural properties of prepared SBA‐15 are found close to those prepared by pure chemicals. Furthermore, the synthesized mesoporous silica (SBA‐15) from CFA is used as support in Fischer–Tropsch synthesis (FTS). The obtained mesoporous material has a surface area of 643 m2/g and a pore size of 8.24 nm. Co–Fe bimetallic catalyst containing 15 wt% of cobalt and 5 wt% of iron is prepared by incipient wetness impregnation of cobalt nitrate and iron nitrate salts over CFA‐derived SBA‐15. These mesoporous support and catalyst are characterized by X‐ray diffraction (XRD), N2 adsorption–desorption, H2‐temperature‐programmed reduction (TPR), NH3‐temperature‐programmed desorption (TPD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). FTS experiment is showing 65.53% of C5+ selectivity. The results indicate that the nanosubstrate material derived from CFA may be used as support for FTS activity with further improvements.

Mechanochemical sulfidization of a mixed oxide-sulphide copper ore by co-grinding with sulfur and its effect on the flotation efficiency

Mechanochemical sulfidization of a mixed sulfide/oxide copper ore by co-grinding with sulfur and additives including Mg(NO3)2 and Fe(NO3)3 salts and iron, aluminum and magnesium powders was investigated for the first time. Also, the influence of sulfidization during the wet-milling process was examined on the separation efficiency and recovery of copper in detail. The results demonstrated that co-grinding with sulfur solely had the best flotation performance at the value of 0.5 wt.% and it was attributed to the possible existence of SO bonding on copper oxides surfaces. In addition, adding magnesium nitrate salt, magnesium powder, iron nitrate salt and aluminum powder as additive associated with 0.5 wt% sulfur into ball milling caused the flotation improvement at the amounts of 0.2 wt%, 0.2 wt%, 0.5 wt% and 0.5 wt%, respectively. Also, the effect of grinding time and sulfidization pH with 0.5 wt% sulfur solely was determined and pHs of 7.5 to 8.5 gave the best results. The highest recovery (75.76%) and separation efficiency (63.44%) were achieved at pH of 7.5 and 8.5, respectively.

Magnetic Carbon Nanocages: An Advanced Architecture with Surface- and Morphology-Enhanced Removal Capacity for Arsenites

Magnetic carbon nanocages (Mag@CNCs) were synthesized via a green one-step process using pine resin and iron nitrate salt as a carbon and iron source, respectively. To produce Mag@CNCs, pristine materials have been carbonized at high temperature under inert atmosphere. The structural, textural, and surface properties of as-synthesized Mag@CNCs were studied employing microscopic, spectroscopic, and surface physicochemical methods. The obtained results showed that the new Mag@CNCs have significant surface area (177 m2 g–1) with both microporosity and mesoporosity. Moreover, the material exhibits a homogeneous distribution of core–shell-type magnetic nanoparticles within the carbon matrix, formed by iron carbide (Fe3C) and metallic iron (α-Fe), with sizes of 20–100 nm, surrounded by a few graphitic layers-walls. Most importantly, Mag@CNCs were tested as absorbents for As(III) removal from aqueous solutions, showing a total of 263.9 mg As(III)-uptake capacity per gram of material at pH = 7, a record sorption ...

Synthesis and characterization of Co–Fe nanoparticles supported on mesoporous silicas

Co–Fe bimetallic samples containing 25 wt% total of metal content were prepared by incipient wetness impregnation of cobalt nitrate and iron nitrate salts over hexagonal mesoporous silica (HMS) and SBA-15 supports. Changes in the textural properties and reduction behavior were compared with monometallic cobalt/iron-based samples. The samples were characterized by N2 physisorption, X-ray diffraction (XRD), H2-temperature programmed reduction (TPR), transmission electron microscopy (TEM) and H2 chemisorption. The amount of incorporated metal was estimated by atomic absorption spectroscopy (AAS). Morphological properties revealed that after introduction of the metal to the SBA-15 support, the specific area, pore volume and pore diameter decreased to a lesser extent for bimetallic samples. XRD measurements detected the formation of Co3O4 and CoFe2O4 phases for both bimetallic samples. TPR profiles indicated similar behavior for both the bimetallic and monometallic samples. Higher temperatures were observed for the reducibility of Co–Fe/HMS as compared to Co–Fe/SBA-15. Dispersion values of the bimetallic samples were higher than Fe monometallic samples and lower than Co monometallic samples according to hydrogen chemisorption. The particle size distribution of the bimetallic samples estimated by TEM microphotographs showed a smaller fraction of larger size particles for Co–Fe/SBA-15.

Synthesis of cobalt–iron bimetallic nanocrystals supported on mesoporous silica using different templates

CoFe bimetallic samples containing 25 wt% total of metal content were prepared by incipient wetness impregnation of cobalt nitrate and iron nitrate salts over hexagonal mesoporous silica (HMS). A series of HMS silicas have been prepared by a neutral assembly pathway using two types of structure director: dodecylamine (DDA) and tetradecylamine (TDA). The effect of different templates in the formation of HMS mesoporous silica and bimetallic CoFe supported samples has been investigated and characterized by N 2 physisorption, X-ray diffraction (XRD), temperature programmed reduction (TPR), hydrogen chemisorption, thermogravimetric (TGA) and differential thermal (DTA) analyses. The amount of incorporated metal was estimated by atomic absorption spectroscopy (AAS). Also, a series of supported monometallic cobalt/iron samples were synthesized and compared to bimetallic ones. The textural properties revealed a lower percentage decrease in BET area and total pore volume for the CoFe/HMS (DDA) sample. XRD results showed α-Fe 2O 3 phase formation and higher Co 3O 4/CoFe 2O 4 crystallite sizes for CoFe/HMS (TDA) sample. The latter also presented lower reduction temperatures and a slightly lower dispersion (%) compared to CoFe/HMS (DDA).

Formation of γ-Fe2O3 Isolated Nanoparticles in a Silica Matrix

Isolated nanometric particles (D < 30 nm) of γ-Fe2O3 in a silica matrix have been prepared by heating at 400 °C the gel formed in the hydrolysis of an ethanol solution of Fe(NO3)3·9H2O and tetraethylorthosilicate (TEOS). However, when FeCl3·6H2O was used as precursor, well-developed hematite particles were obtained in the final composite. This different behavior was already manifest in the initial gels. Thus, the gel obtained from iron nitrate salt shows a compact appearance as a result of its higher degree of network connectivity (polymeric gel) whereas the one from the iron chloride appears more loose and highly hygroscopic (colloidal gel). In addition, small superparamagnetic nuclei are formed during the hydrolysis and condensation of the gel obtained from the iron nitrate salt. The γ-Fe2O3 nanoparticle formation takes place through a reduction−oxidation reaction which occurs during the burning of the organic species trapped inside the gel pore. The growth mechanism of the γ-Fe2O3 nanoparticles in the ...