CeCl3 Research Articles

Polymorph and Morphology Formation of Cerium Carbonate from Reactive Crystallization

Semibatch reactive crystallization and hydrothermal reaction of cerium carbonate were investigated with cerium chloride and sodium carbonate as the reactants in order to determine the key factor and the foremost step that affect the polymorph and morphology. Pure Ce2(CO3)3·8H2O, pure CeCO3OH, and the concomitant polymorphism of the two were obtained at different temperatures and the concentrations of cerium chloride solution. The relative stability of Ce2(CO3)3·8H2O and CeCO3OH, the solubilities of the two forms in low concentration of sodium chloride solution and the dehydration and decomposition processes with heating were first discussed in this study. Rodlike forms, short rodlike forms, platelike aggregations or blocks, regular intercrescence, and regular spindle morphology of cerium carbonate crystals were obtained from semibatch and hydrothermal reactive crystallization, respectively. Raman spectroscopy and a focused beam reflection measuring (FBRM) instrument were applied in situ to monitor the reaction, nucleation, and growth processes. It was found that CeCO3OH is more stable than Ce2(CO3)3·8H2O. The thermodynamics driving force of supersaturation of cerium carbonate generated from the reaction between cerium chloride and sodium carbonate at different temperatures contributed mainly to the nucleation, which, in turn, controls the crystal phase formation and the morphology of cerium carbonate. Finally, the routes for cerium chloride and sodium carbonate to transform into cerium oxide were summarized.

Removal of phosphate from brewery wastewater by cerium(III) chloride originating from spent polishing agent: Recovery and optimization studies

This paper presents the possibility of using hydrated cerium(III) chloride (CeCl3∙7H2O) recovered from a spent polishing agent containing cerium(IV) dioxide (CeO2) to remove phosphate and other impurities from brewery wastewater (phosphate 43.0 mg/L, total P 19.8 mg/L, pH 7.5, COD(Cr) 827 mg O2/L, TSS 630 mg/L, TOC 130 mg/L, total N 46 mg/L, turbidity 390 NTU, colour 170 mg Pt/L. CCD (Central Composite Design) and RSM (Response Surface Methodology) were applied to optimise the brewery wastewater treatment process. The removal efficiency (mainly of PO43−) was the highest under optimal conditions (pH 7.0–8.5, Ce3+:PO43− molar ratio of 1.5–2.0). Applying recovered CeCl3 under optimal conditions yielded a treated effluent in which the concentration of PO43− decreased by 99.86 %, total P by 99.56 %, COD(Cr) by 81.86 %, TSS by 96.67 %, TOC by 60.38 %, total N by 19.24 %, turbidity by 98.18 %, and colour by 70.59 %. The Ce3+ ion concentration in the treated effluent was 0.058 mg/L. These findings suggest that CeCl3‧7H2O recovered from the spent polishing agent may constitute an optional reagent for phosphate removal from brewery wastewater. The sludge from wastewater treatment can be recycled for Ce and P recovery. The recovered cerium can be reused for wastewater treatment, creating a cyclic cerium cycle in the process, and the recovered phosphorus can be used, for example, for fertilization purposes. The optimised cerium recovery and application is in accordance with the ideas of circular economy.

Corrosion of Synthetic Intermetallic Compounds and AA7075-T6 in Dilute Harrison’s Solution and Inhibition by Cerium(III) Salts

This study addresses the behavior of an aluminum alloy and its components in conditions simulating the presence of atmospheric salts. The corrosion of synthetic intermetallic compounds (IMCs) Al2Cu, Al2CuMg, Al7Cu2Fe, MgZn2, and bulk aluminum alloy 7075-T6 was studied in dilute Harrison’s solution (DHS, 0.35 wt% (NH4)2SO4 + 0.05 wt% NaCl). For IMCs, electrochemical measurements were performed using a microcell, and a standard electrochemical cell was used to study the bulk alloy. Separately measured cathodic and anodic potentiodynamic polarization curves were recorded, and prolonged immersion was characterized using electrochemical impedance spectroscopy. Samples were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Bulk AA7075-T6 was less susceptible to corrosion in DHS than in chloride solution stemming from the beneficial presence of sulfate ions and lower chloride concentration. The susceptibility of IMCs to corrosion in DHS increased in the order Al2Cu < Al7Cu2Fe < Al2CuMg < MgZn2 due to the increased dissolution of Mg in the presence of ammonium ions. The relative nobility of IMCs was determined based on the galvanic current density. Further, the possibility of using cerium chloride, nitrate and acetate salts as corrosion inhibitors in DHS was evaluated. Ce salts acted as inhibitors for the alloy during 14 d testing, forming a Ce hydroxide layer. The degree of protection depended on the type of anion, with acetate Ce salt giving the most efficient protection. For the IMC, however, inhibition by Ce salts did not occur during short measurements in the microcell, indicating the importance of galvanic interaction with the alloy matrix in the inhibition mechanism, which was confirmed by long-term measurements of the alloy.

Process study of CeO2 preparation by jet-flow pyrolysis via microwave heating

The spray pyrolysis method has the disadvantage of nozzle plugging, and the conventional heating model causes a large temperature gradient, which leads to unevenly heated reactants. This study used cerium chloride heptahydrate and Venturi reactor as raw material and core equipment. The technology of microwave heating was combined to prepare single-phase sphere-like cerium oxide. The mean size of the particles was near 80nm. The product was characterized via XRD, SEM, and EDS technologies. The purity, morphology, and energy consumption were compared with the conventional spray pyrolysis. Fluent software coupled with HFSS was employed to simulate the effects of different process conditions on products? purity and temperature field in the reactor. There was good correspondence between experimental and simulated results. The results showed that as gas velocity Vg increased, the tendency of the temperature field distribution did not change. The lowest mass fraction of chlorine element reached 0.13% when the gas inlet velocity reached 1.7 m/s. When the material inlet velocity was 0.05 m/s, the mass fraction of the chlorine element was below 0.1%, which indicated that the reactants had a complete reaction. It has been calculated that the heating cost, energy consumption, and CO2 emission decreased sharply compared with the spray pyrolysis method.

Imidazolin-2-iminato Cerium(IV) Chlorides: Synthesis, Structure and Electrochemical Properties.

The ligand field greatly affects the redox properties of cerium. Herein, cerium(III) and cerium(IV) complexes supported by imidazolin-2-iminato ligands were synthesized and structurally characterized, and their electrochemical properties were investigated. Silylamine elimination of cerium(III) amide Ce{N(SiMe3 )2 }3 with imidazolin-2-imine ImR NH (R=Mes, tBu, iPr) provided imidazolin-2-iminato cerium(III) complexes, [(ImMes N)(ImMes NH)Ce{N(SiMe3 )2 }2 ] (1), [(ImtBu N)2 (ImtBu NH)Ce{N(SiMe3 )2 }] (2) and [(ImiPr N)2 (ImiPr NH)Ce(μ-ImiPr N)]2 (4) in 71-85% yields. These cerium(III) complexes were successfully oxidized by Ph3 CCl or C2 Cl6 to afford imidazolin-2-iminato cerium(IV) chlorides, [(ImMes N)2 Ce{N(SiMe3 )2 }Cl] (5), [(ImtBu N)3 CeCl] (6) and [(ImiPr N)2 Ce(μ-ImiPr N)Cl]2 (7) in 70%-76% yields. All complexes were characterized by the single-crystal X-ray diffraction, which showed that 1, 2, 5 and 6 are monomers while 4 and 7 are dimers. The electrochemical studies indicated that the Ce(III/IV) couples for 5 and 6 are more negative than those of silylamido cerium(IV) complexes, and the Ce(III/IV) couples for 1 and 2 have a similar trend.

Surface Accumulation of Cerium, Self-Assembling Peptide, and Fluoride on Sound Bovine Enamel.

The accumulation of caries-preventive compounds on sound enamel is crucial in order to improve the inhibition of carious lesion initiation. The aim of this research was to investigate the initial accumulation of cerium, oligopeptide p11-4, and fluoride from NaF or amine fluoride (AmF) on sound enamel in vitro by means of energy dispersive X-ray spectroscopy (EDX). Polished bovine enamel specimens (n = 120 from 60 teeth) were fabricated. Out of these, 12 specimens each were treated with CeCl3 (cerium(III) chloride heptahydrate 25%), oligopeptide p11-4 (Curodont Repair, Credentis), NaF (10,000 ppm F-), AmF (amine fluoride, Elmex Fluid, CP-GABA GmbH, 10,000 ppm F-), or Aqua demin (control). After rinsing with water, the surface elemental composition (Ce, N, F, Ca, P, O, Na, Mg) was measured (EDX; EDAX Octane Elect detector, APEX v2.0), expressed in atomic percent (At%) and analyzed (non-parametric statistics, α = 0.05, error rates method). Another 12 specimens per treatment group were fabricated and used for analyzing accumulation in cross-sections with EDX linescans and two-dimensional EDX-mappings. The surface median atomic percent of cerium (At%Ce) was 0.8 for CeCl3, but no Ce was found for any other group. N, specifically for oligopeptide p11-4, could not be detected. Fluorine could only be detected on fluoridated surfaces. The median atomic percent of fluorine (At%F) was 15.2 for NaF and 17.0 for AmF. The Ca/P ratio increased significantly compared to the control following the application of NaF and AmF (p &lt; 0.001), but decreased significantly for CeCl3 (p &lt; 0.001). In cross-sectioned specimens of the CeCl3-group, 12.5% of the linescans revealed cerium at the enamel surface, whereas 83.3% of the NaF linescans and 95.8% of the AmF linescans revealed fluorine at the enamel surface. Following the application of oligopeptide p11-4, no traces of N were detectable. In the depth of the samples, no signal was detected for any of the corresponding elements exceeding the background noise. Cerium and fluorine (from both NaF and AmF), but not the oligopeptide p11-4, precipitated on sound enamel.

Cerium chloride and L-arginine as effective hybrid corrosion inhibitor for 5052 aluminum alloy in 3.5% NaCl solution

Cerium chloride and L-arginine as effective hybrid corrosion inhibitor for 5052 aluminum alloy in 3.5% NaCl solution

Boosting the plasma catalytic performance of CeO2/γ-Al2O3 in long-chain alkane VOCs via tuning the crystallite size

CeO2/γ-Al2O3 catalysts with distinct crystallite sizes were synthesized by changing the precursors of ceria. CeO2/γ-Al2O3 prepared by cerium nitrate (CN) had smaller crystalline size than samples prepared by cerium chloride or cerium acetate. They were evaluated in the plasma catalytic oxidation reaction of n-undecane (C11), which is one of the representative long-chain alkane volatile organic compounds (VOCs). CeO2(CN)/γ-Al2O3 displayed a higher C11 conversion of 100 % with 72 % of CO2 selectivity under ambient conditions with an energy density of 205 J/L, while samples with larger crystalline sizes showed lower activities. X-ray photoelectron spectroscopy analysis confirmed that more concentration of adsorbed oxygen species and higher ratio of Ce3+/(Ce3++Ce4+) existed on the surface of CeO2/γ-Al2O3 samples with smaller crystalline size. Chemisorption experiments further verified that surface oxygen vacancies resulted in the different catalytic activities. In situ diffuse reflectance infrared Fourier transform spectroscopy analyses showed that the oxidation capability of intermediates by-products enhanced with the decrease of crystalline size. Results revealed that the crystallite size of CeO2 had a significant effect on the redox properties. This research provides an insight into the regulation of oxygen vacancy in transition metal oxides to facilitate the plasma catalytic performance of alkane VOCs under mild reaction conditions.

Kinetics of HSA crystallization and its relationship with the phase diagram

Using the protein human serum albumin (HSA) and the trivalent salt cerium chloride (CeCl3) to tune the effective interactions, we induce crystallization and connect the crystallization kinetics to different regions of the phase diagram. The nucleation density, the nucleation rate, as well as the crystal size show maxima slightly above the specific salt concentration c∗ for aggregation. The comparison with data of the reduced second virial coefficient suggests that B2/B2HS alone is insufficient to explain the observed trends. We thus discuss further aspects impacting the crystallization behavior. We are able to link and distinguish the kinetic regimes regarding their relative distance to phase boundaries, namely c∗ as well as the liquid–liquid phase separation (LLPS) border.

ANOVA of Cerium Chloride on Morphology and Metamorphosis Development in Tadpoles of C. melanogaster

In this experiment, the effects of 0.004 mg·L-1, 0.02 mg·L-1, 0.1 mg·L-1, and 0.5 mg·L-1 cerium chloride solutions on the growth and metamorphosis development of the tadpoles of the black spotted frog were investigated. The experimental results showed that cerium chloride solution at 0.5 mg·L-1significantly reduced the survival rate of tadpoles, which was 6.67% at 168h (7d) in the 0.5 mg·L-1 treatment compared with 93.3% in the blank control (lake water). The growth condition (body weight) at 168h (7d) (0.56 g) was different from that of the blank control (lake water) tadpoles (The growth (mass) of tadpoles at 0.5 mg·L-1 slowed down significantly in early development compared to the blank control (lake water) tadpoles (0.67g ± 0.05g); at the same time, we noticed that the tadpoles at 0.5 mg·L-1 concentration were in a dormant state of growth, and the mass was not significantly different compared to the beginning of the experiment. The metamorphosis time of tadpoles in the high concentration of cerium chloride salt solution (31 ± 5 days) was greater than that of the blank control tadpoles (26 ± 3 days). Tadpoles at concentrations of 0.02 mg·L-1, 0.1 mg·L-1, and 0.5 mg·L-1 were significantly heavier than the blank control tadpoles at metamorphosis. The results of this experiment indicated that moderate concentration levels of cerium chloride (0.004 mg·L-1, 0.02 mg·L-1) could significantly accelerate the growth and promote the metamorphosis development of the tadpoles of C. melanogaster.

Dual-Mode Fluorescence/Ultrasound Imaging with Biocompatible Metal-Doped Graphene Quantum Dots.

Sonography offers many advantages over standard methods of diagnostic imaging due to its non-invasiveness, substantial tissue penetration depth, and low cost. The benefits of ultrasound imaging call for the development of ultrasound-trackable drug delivery vehicles that can address a variety of therapeutic targets. One disadvantage of the technique is the lack of high-precision imaging, which can be circumvented by complementing ultrasound contrast agents with visible and, especially, near-infrared (NIR) fluorophores. In this work, we, for the first time, develop a variety of lightly metal-doped (iron oxide, silver, thulium, neodymium, cerium oxide, cerium chloride, and molybdenum disulfide) nitrogen-containing graphene quantum dots (NGQDs) that demonstrate high-contrast properties in the ultrasound brightness mode and exhibit visible and/or near-infrared fluorescence imaging capabilities. NGQDs synthesized from glucosamine precursors with only a few percent metal doping do not introduce additional toxicity in vitro, yielding over 80% cell viability up to 2 mg/mL doses. Their small (&lt;50 nm) sizes warrant effective cell internalization, while oxygen-containing surface functional groups decorating their surfaces render NGQDs water soluble and allow for the attachment of therapeutics and targeting agents. Utilizing visible and/or NIR fluorescence, we demonstrate that metal-doped NGQDs experience maximum accumulation within the HEK-293 cells 6-12 h after treatment. The successful 10-fold ultrasound signal enhancement is observed at 0.5-1.6 mg/mL for most metal-doped NGQDs in the vascular phantom, agarose gel, and animal tissue. A combination of non-invasive ultrasound imaging with capabilities of high-precision fluorescence tracking makes these metal-doped NGQDs a viable agent for a variety of theragnostic applications.

Cytological alterations and oxidative stress induced by Cerium and Neodymium in lentil seedlings and onion bulbs

Rare earth elements (REEs) are a group of 15 elements, the lanthanides and Yttrium and Scandium, with similar chemical and physical properties. Their use for many advanced technological applications remarkably increased in the last decades, and it was associated with an intensive extraction of such elements from their ores. Consequently, increasing amounts of either REE-containing by-products, deriving from the extraction process, and REE-containing wastes, deriving from the disposal of REE-containing devices, are reaching the environmental systems both at the local and global levels, as never in the past. Few data in the literature concern the effect (beneficial or toxic) induced by REEs application in terrestrial plant species and at different physiological stages. A set of experiments with exposure to two REEs was performed on some plants to evaluate this. Data of investigations focused on the exposure of lentil (Lens culinaris Medik.) seedlings and onion (Allium cepa L.) bulbs to cerium chloride (CeCl3) and neodymium chloride (NdCl3) at different concentrations for 72 h. Results showed alteration of the growth rate and the levels of some parameters considered as biomarkers of stress (reactive oxygen species and antioxidant systems). An increase in some mitotic aberrations was also observed in the root tissues of both species. The results indicate that the sensitivity of lentil in this bioassay is higher for lower concentrations compared to onion. Also, lower concentrations of these REEs had a positive effect on the growth rate of lentils underlining the complex interaction occurring between REEs and different plant organisms.

A Self-Regulated Electrostatic Shielding Layer toward Dendrite-Free Zn Batteries.

Although aqueous Zn batteries have become a more sustainable alternative to lithium-ion batteries owing to their intrinsic security, their practical applications are limited by dendrite formation and hydrogen reactions. The first application of a rare earth metal type addition to Zn batteries, cerium chloride (CeCl3 ), as an effective, low-cost, and green electrolyte additive that facilitates the formation of a dynamic electrostatic shielding layer around the Zn protuberance to induce uniform Zn deposition is presented. After introducing CeCl3 additives, the electrochemical characterizations, in situ optical microscopy observation, in situ differential electrochemical mass spectrometry, along with density functional theory calculations, and finite element method simulations reveal resisted Zn dendritic growth and enhanced electrolyte stability. As a result, the Zn-Zn cells using the CeCl3 additive exhibit a long cycling stability of 2600 h at 2mA cm-2 , an impressive cumulative areal capacity of 3.6 Ah cm-2 at 40mA cm-2 , and a high Coulombic efficiency of ≈99.7%. The fact that the Zn-LiFePO4 cells with proposed electrolyte retain capacity significantly better than the additive-free case is even more exciting.

Synthesis and Characterization of 1-D Cerium Oxide to Study Their Humidity Sensing Application

Abstract: The formaldehyde-assisted hydrothermal system is used to synthesize CeO2 nanorods by using precursor like cerium chloride. Concentration of precursors and hydrothermal temperature affects the morphologies of these one-dimensional (1D) CeO2 Nanomaterial’s. This is achieved to control the reaction degree of Cannizzaro disproportionation tuned by Na/Ce molar ratio. The XRD, FESEM, FTIR and TEM these characterization techniques have been used to characterize the crystal structure and morphology of the as-synthesized CeO2. Humidity sensing characteristics such as hysteresis, repeatability, impedancerelative humidity (RH) characteristics, response and recovery behavior, and stability of CeO2 nanostructure have been investigated in detail for given precursor. The sensor showed rapid response and recovery, prominent stability, high humidity sensitivity, good repeatability and narrow hysteresis loop i.e. suitable candidate for the fabrication of the humidity sensors.

Deoxidation of Titanium Using Cerium–Chloride Flux for Upgrade Recycling of Titanium Scraps

Deoxidation of Titanium Using Cerium–Chloride Flux for Upgrade Recycling of Titanium Scraps

Transdermal permeation of inorganic cerium salts in intact human skin

The stratum corneum protects the body against external agents, such as metals, chemicals, and toxics. Although it is considered poorly permeable to them, comprising the major barrier to the permeation of such substances, it may become a relevant gate of entry for such molecules. Cerium (Ce) is a lanthanide that is widely used in catalytic, energy, biological and medicinal applications, owing to its intrinsic structural and unique redox properties. Cerium salts used to produce cerium oxide (CeO2) nanostructures can potentially come into contact with the skin and be absorbed following dermal exposure. The objective of this study was to investigate the percutaneous absorption of three inorganic Ce salts: cerium (III) chloride (CeCl3); cerium (III) nitrate (Ce(NO3)3) and ammonium cerium (IV) nitrate (Ce(NH4)2(NO3)6), which are commonly adopted for the synthesis of CeO2 using in vitro - ex vivo technique in Franz diffusion cells. The present work shows that Ce salts cannot permeate intact human skin, but they can penetrate significantly in the epidermis (up to 0.29 μg/cm2) and, to a lesser extent in dermis (up to 0.11 μg/cm2). Further studies are required to evaluate the potential effects of long-term exposure to Ce.

Application of CeO2-V2O5 catalysts in the oxidative desulfurization of 4,6-dimethyl dibenzothiophene as a model reaction to remove sulfur from fuels

Oxidative desulfurization (ODS) is an excellent alternative for removing sulfur from fuels and the accurate choice of catalyst is essential in obtaining good conversion. In this study, V2O5 and CeO2 catalysts and their mixture were prepared by incipient impregnation method from ammonium metavanadate and cerium chloride as precursors. The catalysts were characterized by different physicochemical techniques. The acidity of the catalyst was measured potentiometrically by titration with pyridine and using a platinum electrode. The catalytic properties of the synthesized catalysts were evaluated in the ODS of 4,6-dimethyl dibenzothiophene. Acidity increased with the addition of vanadium, which generated more variants in the oxidation state of V2O5 and improved the catalytic activity. The vanadium catalyst with the highest amount of vanadium oxide achieved a conversion rate of nearly 100%, renders a viable catalyst for sulfur removal. Factors such as acidity and surface area affect the catalytic activity.

Effect of Cerium Chloride on the Self-Corrosion and Discharge Activity of Aluminum Anode in Alkaline Aluminum-air Batteries

One of the key impediments to aluminum (Al) as an anode in alkaline Al-air batteries is self-corrosion, which limits the battery’s efficiency due to the capacity loss and lifespan reduction. Thus, it is vital to find an efficient electrolyte additive that reduces self-corrosion in Al anodes. In this study, the effect of adding 0.5 to 1.5 wt% of cerium chloride to 4 mol l−1 KOH electrolyte on the self-corrosion of pure Al anode was investigated using electrochemical experiments. The results show that the addition of cerium chloride to the electrolyte reduces self-corrosion of the Al anode with a negligible effect on the anode activity. Cerium chloride forms cerium hydroxide (Ce (OH)3) in the alkaline electrolyte, which is adsorbed on the Al surface. Therefore, the corrosion potential increased, and self-corrosion current density decreased. As the cerium chloride concentration increased, the Al anode efficiency increased from 43.8% to 76.1%, and the capacity density increased from 1294 to 2244 mAh g−1. Furthermore, increasing the immersion time of the Al anode in the electrolyte containing cerium chloride increased the self-corrosion resistance and provided the self-healing properties for the anode.

Giant effective magnetic fields from optically driven chiral phonons in 4f paramagnets

We present a mechanism by which optically driven chiral phonon modes in rare-earth trihalides generate giant effective magnetic fields acting on the paramagnetic $4f$ spins. With cerium trichloride (CeCl$_3$) as our example system, we calculate the coherent phonon dynamics in response to the excitation by an ultrashort terahertz pulse using a combination of phenomenological modeling and first-principles calculations. We find that effective magnetic fields of over 100 tesla can possibly be generated that polarize the spins for experimentally accessible pulse energies. The direction of induced magnetization can be reversed by changing the handedness of circular polarization of the laser pulse. The underlying process is a phonon analog of the inverse Faraday effect in optics that has been described recently, and which enables novel ways of achieving control over and switching of magnetic order at terahertz frequencies.

Ion solvation and association and water structure in an aqueous cerium (III) chloride solution in the gigapascal pressure range.

X-ray diffraction measurements are performed on a 1m (= mol kg-1) CeCl3 aqueous solution over a temperature range of 300-600K and a pressure range of 0.1MPa to 4 GPa. The experimental interference functions are analyzed by an empirical potential structure refinement (EPSR) modeling. The Ce3+ coordinates water molecules in a tricapped trigonal prism configuration under the ambient condition. The number of water molecules around Ce3+ changes from 8.8 at 0.1MPa/300K to 11.5 at 4 GPa/600K. The number of water molecules around Cl- changes drastically from 10 under the ambient condition to 17 at 4 GPa/600K. The tetrahedral-like network structure of water under the ambient condition is transformed toward a simple liquid-like packing in the GPa pressure range. The corresponding coordination number is increased from 4.3 in the ambient condition to 9.7 at 4 GPa/600K. The Ce3+-Cl- association decreases with increasing pressure.