Interaction Of Mn Research Articles

Significantly Enhanced Electromagnetic Wave Absorption Performances and Corresponding Mechanism of LaMn1-xFexO3 Perovskites

Improving the performance of LaMnO3 perovskite is essential to make it an efficient and ultra-light electromagnetic wave (EMW) absorbing material. In this work, LaMn1-xFexO3 powders (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) were synthesized by controlling the doping of Fe3+ ions at the B-site using the citric acid-assisted sol-gel method. The effects of Fe3+ ions doping content on crystal structures, magnetic properties and EMW absorption performances were investigated. The obtained LMFO-4 sample exhibited a minimal reflection loss of -54.99 dB at 13.68 GHz, with an adequate absorption bandwidth (RL < -10 dB) spanning 4.56 GHz (11.6∼16.16 GHz) at a matching layer thickness of 2.0 mm. The exceptional EMW absorption performances could be attributed to the Jahn-Teller effect, the double-exchange interactions and the magnetic interactions of Mn and Fe ions. Furthermore, the Computer Simulation Technology (CST) simulations demonstrated that the Radar Cross Section (RCS) value of LMFO-4 was lower than -25.10 dBm2 across angles ranging from -90° to 90° with a thickness of 2.0 mm, indicating the remarkable radar wave attenuation ability. These insights provided valuable guidance for advancing perovskite-based materials tailored for efficient and ultra-light electromagnetic wave absorption applications.

Polymetallic MnW/Co3O4 porous composites derived from polyoxometalate-induced “cage-within-cage” zeolitic imidazolate frameworks with high efficiency towards NOx reduction

Exploitation of highly active, economical and environmentally friendly catalysts is the primary imperative for addressing the pivotal concerns confronting NOx pollution. Transition metal oxides have shown good application prospects in NOx purification due to their plentiful availability and affordable pricing. Herein, a confinement-pyrolysis strategy for preparation of MnW/Co3O4 composites with porous structures and high dispersion of active components transformed from polyoxometalate (POM)-encapsulated zeolitic imidazolate frameworks (ZIFs) was showcased. The strong interaction of Mn and Co contributes to the production of rich Mn3+ and Co3+ content (Mn4+ + Co2+ → Mn3+ + Co3+; Mn2+ + Co3+ → Mn3+ + Co2+). Compared with W/Co3O4, the Mn addition can increase the accessibility of active sites, induce more oxygen vacancies, acid sites and defects formation at the interfacial regions, promote the adsorption and activation of NH3 and NO, resulting in a 10–50 % higher NOx conversion at the 100−300 °C under 40,000 h−1. More encouragingly, experimental results suggested that the Mn-containing catalyst also exhibits much better tolerance against SO2, H2O, and HC than the Mn-free catalyst. This work demonstrates that guest@host POM@ZIF-functionalized derivative materials possess promising application perspective for low-temperature NOx reduction.

Exposure to Multiple Metal(loid)s and Hypertension in Chinese Older Adults.

Evidence about effects of metal(loid)s on hypertension among adults is insufficient. The aim of our study was to evaluate the individual and joint associations between seven selected metal(loid)s and hypertension, including lead (Pb), manganese (Mn), nickel (Ni), arsenic (As), cadmium (Cd), chromium (Cr), and vanadium (V)) in Chinese older adults. This study included 1009 older adults, and the blood concentrations of seven metal(loid)s were evaluated by inductively coupled plasma mass spectrometry (ICP-MS). The following conditions were considered as hypertension: (1) either systolic blood pressure ≥ 140mm Hg or diastolic blood pressure ≥ 90mm Hg, (2) a self-reported history of hypertension, or (3) currently taking antihypertensive medications. Logistic regression was utilized to investigate the association between individual metal(loid) and hypertension, while Bayesian kernel machine regression (BKMR) was employed to investigate the association of the metal(loid) mixture with hypertension. Adjusted single-metal(loid) model showed a significant positive association between Pb and hypertension (OR = 1.24, 95%CI = 1.03-1.50). This significant association still existed in multi-metal(loid) model (OR = 1.22, 95%CI = 1.01-1.47). BKMR further indicated a positive linear association of Pb with hypertension. The metal(loid) mixture was positively associated with hypertension in older adults, although not significant. Within the mixture, Pb had the highest posterior inclusion probabilities value (PIP = 0.9192). There were multiplicative interactions of Pb and Mn on hypertension. In addition, Pb and Mn had additive effects on the association of other blood metal(loid)s with hypertension. The associations of multiple metal(loid)s with hypertension are dependent on diabetes, areas, age, and BMI. The metal(loid) mixture exposure may contribute to hypertension in Chinese older adults, mainly driven by Pb and interactions of Pb and Mn. Reducing exposure to these metal(loid)s may prevent hypertension among older adults, which is especially true for those living with diabetes.

Periodate-driven efficient degradation of diverse pharmaceuticals with iodine-doped MnO2

This research investigated the development of a novel catalyst for contaminant remediation. The strategy involved enhancing the catalytic effectiveness of MnO2 by strategically incorporating iodine, resulting in I-MnO2. Electron paramagnetic resonance (EPR) spectroscopy confirmed an augmentation in oxygen vacancies upon iodine inclusion, leading to increased catalytic activity. I-MnO2 was evaluated as an efficient catalyst within an advanced oxidation process for ciprofloxacin removal through periodate activation. The system achieved a 91.2 % degradation of 20 ppm ciprofloxacin within 9 min, demonstrating a strong correlation between catalyst and oxidant dosages. The I-MnO2/IO4¯ system exhibited remarkable stability across a broad pH range and minimal susceptibility to ionic strength variations, water anions, and humic acid presence. Quenching experiments coupled with EPR analysis suggested the involvement of singlet oxygen (1O2) and iodate radicals (IO3•) generated from the interaction of the metastable Mn(IV)-O-IO3 species with ciprofloxacin. X-ray photoelectron spectroscopy analysis of Mn 2p and O 1s orbitals, performed before and after reactions, further corroborated the role of I-MnO2 in facilitating periodate activation by promoting the conversion of Mn(II) and Mn(III) to Mn(IV) species. This innovative catalyst demonstrates exceptional efficiency in eliminating high concentrations of organic pollutants, suggesting its potential for practical and cost-effective applications in wastewater treatment.

Synthesis of Co(II), Mn(II), and Ni(II) complexes with 4-(4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-yl)morpholine; X-ray structure, Hirshfeld, AIM, and biological studies

Three transition metal complexes of s-triazine ligand (MorphBPT) were synthesized, characterized, and their supramolecular structures are explored. Their structures are confirmed to be [Co(MorphBPT)2](ClO4)2 (1), [Mn(MorphBPT)2](ClO4)2 (2), and [Ni(MorphBPT)(H2O)3]Cl2·2H2O (3) using single crystal X-ray diffraction. In all cases, the MorphBPT is a tridentate N-chelator. Hence, the metal ions have hexa-coordination environment in all complexes. In the two homoleptic complexes 1 and 2, the O···H, C···H, and C···O contacts, in addition to some short N···O and H···H contacts detected only in 2, are the most important. For 3, the Cl···H, O···H, and C···H contacts are the most significant. Enrichment ratio was used to detect the atom pairs which have the highest probability to form non-covalent interactions. The nature of MN and MO coordination interactions is analyzed with the aid of AIM calculations. Also, the interactions with the ligand moieties lowers the charge of Co(II), Ni(II), and Mn(II) to 0.8411, 0.9332, and 0.8308 e, respectively. The three complexes 1, 2, and 3 exhibited antibacterial activity exceeds the reference drug gentamicin against P. vulgaris where the diameter of the inhibition zones (DIZs) are determined to be 28, 29, 27, and 25 mm, respectively. In addition, 1 and 2 have antifungal activity better (DIZ = 18 mm) and equal (DIZ = 17 mm) compared to ketoconazole against A. fumigatus, respectively. The Mn(II) complex 2 is the most active against MCF-7 (75.3 ± 3.1 μM) and A-549 (40.2 ± 2.7 μM) cancerous cell lines.

The Manganese-Bone Connection: Investigating the Role of Manganese in Bone Health.

The complex relationship between trace elements and skeletal health has received increasing attention in the scientific community. Among these minerals, manganese (Mn) has emerged as a key element affecting bone metabolism and integrity. This review examines the multifaceted role of Mn in bone health, including its effects on bone regeneration, mineralization, and overall skeletal strength. This review article is based on a synthesis of experimental models, epidemiologic studies, and clinical trials of the mechanisms of the effect of Mn on bone metabolism. Current research data show that Mn is actively involved in the processes of bone remodeling by modulating the activity of osteoblasts and osteoclasts, as well as the main cells that regulate bone formation and resorption. Mn ions have a profound effect on bone mineralization and density by intricately regulating signaling pathways and enzymatic reactions in these cells. Additionally, Mn superoxide dismutase (MnSOD), located in bone mitochondria, plays a crucial role in osteoclast differentiation and function, protecting osteoclasts from oxidative damage. Understanding the nuances of Mn's interaction with bone is essential for optimizing bone strategies, potentially preventing and managing skeletal diseases. Key findings include the stimulation of osteoblast proliferation and differentiation, the inhibition of osteoclastogenesis, and the preservation of bone mass through the RANK/RANKL/OPG pathway. These results underscore the importance of Mn in maintaining bone health and highlight the need for further research into its therapeutic potential.

Magnetocaloric effect and phase transformation of Zn-doped Ni–Mn–Ti all-d metal Heusler alloys

Ni–Mn–Ti Heusler alloys have gained a great consideration recently due to their important magnetoresistance and magnetocaloric properties. Herein, the structure, martensitic transition (MT), and magnetocaloric effect (MCE) of Ni50-xZnxMn35Ti15 (x = 0, 2, 4, and 6) Heusler alloys have been studied. XRD results show that the studied alloy with x = 0 display a monoclinic (5 M) martensite phase. Besides, the examined alloy with x = 2 presents a combination of monoclinic (5 M) martensite and cubic (B2) austenite phases, whereas the alloys with x = 4 and x = 6 exhibit only a cubic (B2) austenite phase. By increasing Zn content x up to 6, the Curie temperature of austenite decreases from 283 K to 132 K, and the MT temperatures decrease from ferromagnetic austenite to weak-magnetic martensite, which is apparently due to the exchange interaction of Mn–Mn and the low power of d-d hybridization between the A/C and B(D) sites. The best maximum magnetic entropy change (ΔSM, max) and refrigeration capacity (RC) are for the studied alloy with x = 4 (5.22 J kg−1K−1 and 217 J kg−1 at 120 kOe, respectively). The Zn addition not only facilitates the formation of B2-type Heusler phases but also offer the possibility to tune the MT and establish strong ferromagnetic coupling.

Non‐Epitaxial Electrodeposition of Overall 99% (002) Plane Achieves Extreme and Direct Utilization of 95% Zn Anode and By‐Product as Cathode

Zn anode protection in Zn‐ion batteries (ZIBs) face great challenges of high Zn utilization rate (i.e., depth of discharge, DOD) and high current density due to the large difficulty in obtaining an extreme overall RTC (relative texture coefficient) of Zn (002) plane. Through the potent interaction of Mn(III)aq and H+ with distinct Zn crystal planes under an electric field, large‐size Zn foils with a breakthrough (002) plane RTC of 99% (i.e., close to Zn single crystal) are electrodeposited on texture‐less substrates, which is also applicable from recycled Zn. The ultra‐high (002) plane RTC remarkably enhances cyclic performance of the Zn anode (70% DOD @ 45.5 mA cm‐2), and the DOD is even up to 95% (@ 28.1 mA cm‐2) with an electrolyte additive of polyaniline. Furthermore, MnO2, the by‐product of electrodeposition, is directly used as cathode of both coin cell and pouch battery, surpassing the cyclic performance exhibited by the majority of Zn||MnO2 batteries in previous instances. These results demonstrate the great potential of our strategy for high‐performance, low‐cost and large‐scale ZIBs.

Non-Epitaxial Electrodeposition of Overall 99 % (002) Plane Achieves Extreme and Direct Utilization of 95 % Zn Anode and By-Product as Cathode.

Zn anode protection in Zn-ion batteries (ZIBs) face great challenges of high Zn utilization rate (i.e., depth of discharge, DOD) and high current density due to the large difficulty in obtaining an extreme overall RTC (relative texture coefficient) of Zn (002) plane. Through the potent interaction of Mn(III)aq and H+ with distinct Zn crystal planes under an electric field, large-size Zn foils with a breakthrough (002) plane RTC of 99 % (i.e., close to Zn single crystal) are electrodeposited on texture-less substrates, which is also applicable from recycled Zn. The ultra-high (002) plane RTC remarkably enhances cyclic performance of the Zn anode (70 % DOD @ 45.5 mA cm-2), and the DOD is even up to 95 % (@ 28.1 mA cm-2) with an electrolyte additive of polyaniline. Furthermore, MnO2, the by-product of electrodeposition, is directly used as cathode of both coin cell and pouch battery, surpassing the cyclic performance exhibited by the majority of Zn||MnO2 batteries in previous instances. These results demonstrate the great potential of our strategy for high-performance, low-cost and large-scale ZIBs.

Unveiling a Family of Dimerized Quantum Magnets, Conventional Antiferromagnets, and Nonmagnets in Ternary Metal Borides.

Dimerized quantum magnets are exotic crystalline materials where Bose-Einstein condensation of magnetic excitations can happen. However, known dimerized quantum magnets are limited to only a few oxides and halides. Here, we unveil 9 dimerized quantum magnets and 11 conventional antiferromagnets in ternary metal borides MTB4 (M = Sc, Y, La, Ce, Lu, Mg, Ca, and Al; T = V, Cr, Mn, Fe, Co, and Ni), where T atoms are arranged in structural dimers. Quantum magnetism in these compounds is dominated by strong antiferromagnetic (AFM) interactions between Cr (Cr and Mn for M = Mg and Ca) atoms within the dimers, with much weaker interactions between the dimers. These systems are proposed to be close to a quantum critical point between a disordered singlet spin-dimer phase, with a spin gap, and the ordered conventional Néel AFM phase. They greatly enrich the materials inventory that allows investigations of the spin-gap phase. Conventional antiferromagnetism in these compounds is dominated by ferromagnetic Mn (Fe for M = Mg and Ca) interactions within the dimers. The predicted stable and nonmagnetic (NM) YFeB4 phase is synthesized and characterized, providing a scarce candidate to study Fe dimers and Fe ladders in borides. The identified quantum, conventional, and NM systems provide a platform with abundant possibilities to tune the magnetic exchange coupling by doping and study the unconventional quantum phase transition and conventional magnetic transitions. This work opens new avenues for studying novel magnetism in borides arising from spin dimers and establishes a theoretical workflow for future searches for dimerized quantum magnets in other families of materials.

Investigation of Si, Mn, and C interactions during coiling of hot rolling model alloys

Model alloys were developed to investigate the interaction of Mn, Si, and C during hot rolling. The alloy samples prepared by the method of vacuum-sealed tube heat treatment exhibited unique microstructural features: surface reduced Fe layer, interface reduced Fe layer and internal oxidation layer. The experimental results revealed that scale reduction is mainly controlled by the effect of Si and decarburization behavior, as well as the contribution of Si is more significant. The competing reactions of decarburization substantially reduce the depth of internal oxidation of the alloy. Additionally, combination of Mn and Si greatly facilitated the process of internal oxidation, with Si playing a role in inducing the inward oxidation of Mn. These insights will contribute to a better understanding of hot rolling coiling process, especially the complex interactions of Mn, Si, and C.

The ordered lattice host framework induced guest Li+ disordering in high performance cobalt-free Ni-rich cathode materials

Recently, due to high price, resource shortage and unstable supply of cobalt, the development of low-cost cobalt-free Ni-rich cathodes has attracted extensive attention with the ever-increasing lithium-ion batteries (LIBs) industry. Selecting cost-effective elements to replace cobalt in Ni-rich cathodes is urgent. However, the principle of structural design of Ni-rich cathode remains unclear, hampering the selection of alternative elements. Herein, the cobalt-free cathodes of LiNi0.95Mg0.05O2 (NiMg) and LiNi0.95Mn0.05O2 (NiMn) are designed as alternatives to LiNi0.96Co0.04O2 (NiCo). NiMg has comparable cycle stability with NiCo, while NiMn has inferior cycle performance. Reverse Monte Carlo modelling was used to generate structural model and uncover local structure by fitting pair distribution function. It reveals Mn causes more severe Jahn-Teller distortions and disordered lattice host framework (Ni0.95M0.05O2, M = Co/Mn/Mg) than Co and Mg due to the strong size effect and coulomb interactions of Mn in Ni0.95Mn0.05O2 layer. The outstanding cycle stability of NiMg and NiCo originates from the ordered lattice host frameworks, which relieve stress and inhibit particle breakage during cycle. Meanwhile, the ordered lattice host framework induced guest Li+ disordering reduces Li+ diffusion energy barrier, improving the rate capability. This study provides a new perspective for the structural design of cobalt-free Ni-rich cathodes.

A new 1D Mn(II) coordination polymer: Synthesis, crystal structure, hirshfeld surface analysis and molecular docking studies

The synthesis of novel metal-organic coordination polymers (MOCP) with the chemical formula [Mn2L (SCN)2(OH)2]3·CH3OH [L = 1,5-bis(pyridine-4-ylmethylene) carbonohydrazide] {1} was accomplished using two different techniques: solvothermal and sonochemical ultrasonic-assisted. An investigation was carried out to examine the impact of various factors such as reaction time, sonication power, temperature, and reactant concentration on the morphology and size of the crystals. Interestingly, it was found that sonication power and temperature did not affect the crystals’ morphology and size. To further analyze the prepared microcrystals of MOCPs, SEM was utilized to examine their surface morphology, and XRD, elemental evaluation composition. The identification of the functional groups present in the prepared Mn-MOCPs was accomplished through the utilization of FT-IR spectroscopy. Subsequently, the calcination of 1 in an air atmosphere at 650 °C led to the formation of Mn3O4 nanoparticles. The geometric and electronic structure of the MOCPs was evaluated using density functional theory (DFT). The utilization of molecular docking methodologies demonstrated that the best cavity of the human androgen receptor possessed an interaction energy of −116.3 kJ mol−1. This energy encompassed a combination of both bonding and non-bonding interactions. The Results showed that steric interaction and electrostatic potential are the main interactions in AR polymer and Mn(II). These interactions in the defined cavity indicated that this polymer could be an effective anti-prostate candidate, because AR is involved in the growth of prostate cancer cells, and these interactions indicated the inhibition of prostate cancer cell growth.

Facile Synthesis of β‐Brominated Manganese Porphyrins and their Catalytic Potentials for Haloperoxidases‐Like Activity

AbstractA novel and sustainable approach has been developed for the synthesis of β‐brominated Mn porphyrins, [MnIII(Br)(TPPBr4)] (2), [MnIII(Br)(TPPBr6)] (3) and [MnIV(Br)2(TPPBr8)] (4) by self catalytic haloperoxidase mimicking activity of [MnIII(Br)(TPP)] [bromo(meso‐tetraphenylporphyrinato)manganese(III)] (1) in aqueous medium under different mild and controlled reaction conditions. By precisely tweaking important parameters (e. g. H2O2, HClO4 and KBr), these polybrominated porphyrin complexes have been synthesized. This method is safer and applicable under milder reaction conditions than the conventional procedures for β‐bromination of porphyrins. These complexes were characterized by various spectroscopic techniques, including UV–Vis spectroscopy, elemental analysis, MALDI‐TOF mass spectrometry, cyclic voltammetry, DFT calculations and single crystal X‐ray diffraction analysis. Bromination of various phenol derivatives via haloperoxidase‐catalyzed reaction using these manganese complexes has been explored. Carrying out the catalytic reaction at room temperature in the presence of H2O2 as an oxidant and KBr as a brominating agent in a mild aqueous acidic condition results in good to excellent yield of the brominated product(s). Extra stability of 4 compared to other catalysts due to trans‐[Br−MnIV−Br] structure possibly prevents the interaction of Mn with oxidant which makes it less potential catalyst compared to 1, 2 and 3. Suitable catalytic reaction mechanism has been proposed for the bromination of substrates after identifying the reaction intermediates using mass spectrometry.

Interfacial confinement effect induced by pre-sulfurization for promoting SO2 tolerance of MnFe-TOS catalyst in low temperature NH3-SCR reaction

SO2 poisoning still is an unresolved problem for NH3-SCR catalysts, especially under low temperature conditions. Herein, a two-pronged approach has been applied on MnFe-TOS for promoting SO2 tolerance at low temperature in NH3-SCR process. Pre-sulfurization via inserting SO42- into TiO2 lattice perturbed the local electronic environment to supplement rich surface acid sites, promoting the rapid adsorption of NH3 at reaction temperature. Active −NH2 and NH4+ could be quickly consumed by NO/nitrites via both L-H and E-R reaction pathway and resulted in high N2 selectivity. The strong interaction of Mn–O–Fe induced by interfacial confinement effect regulated redox ability and inhibited the adsorption/oxidation of SO2, which was benefited to NO activation on MnFe-TOS. At the same time, the (NH4)2SO4 generated during the NH3-SCR process was prone to dissociation into NH4+ and SO42-, where NH4+ continued to participate in the SCR reaction, while SO42- bonded to Fe, as a functional protective site, allowing the Mn site to be protected. DFT calculations have provide convincing evidence at the molecular level to demonstrate how pre-sulfurization induced lattice distortion and affected chemical adsorption characteristics of catalytic active centers (Mn–O–Fe–S). Consequently, the MnFe-TOS exhibited excellent resistance to SO2 at low temperature, and the N2 selectivity has been improved during a wide temperature window. This study provides a new approach for designing efficient and stable NH3-SCR catalysts.

Magnesium and manganese induced changes on chemical, nutritional, antioxidant and antimicrobial properties of the pansy and Viola edible flowers

Pansy and viola edible flowers were grown hydroponically with different levels of Mg and Mn. The nutritional composition was determined using standard methods. Free sugars, fatty acids, organic acids, tocopherols, and phenolic compounds were analyzed using various HPLC and GC devises. The extract's antimicrobial, antioxidant, cytotoxicity, and anti-inflammatory activity were assessed. The results indicated that Mg enrichment negatively affected plant growth and mineral accumulation but improved photosynthetic performance. The edible flowers contained significant amounts of protein, low levels of fat, and varying sugar contents, such as glucose and fructose. Various fatty acids and phenolic compounds were identified, with different concentrations depending on the treatment. The flowers exhibited antioxidant potential, antimicrobial activity, cytotoxic effects, and anti-inflammatory properties. The correlations between the investigated parameters not only expand knowledge on Mg and Mn interaction but also catalyze significant advancements in sustainable agriculture and food health, fostering a healthier and more conscious future.

Unraveling the magnetic properties and nature of exchange interactions of Mn5−x Fe x Ge3 (0.15 ≤ x ≤ 0.5) alloys

We report the structural and magnetic properties of arc-melted Fe-doped Mn5Ge3 alloys. In this study, Mn5−x Fe x Ge3 (x = 0.15, 0.3, and 0.5) alloys were subjected to DC magnetic measurements in order to examine the nature of magnetic interaction via critical exponents study in the asymptotic critical region. The critical exponents β, γ and δ are obtained independently from different methods. For Mn4.85Fe0.15Ge3, β = 0.338, γ = 1.146 and δ = 4.39; for Mn4.7Fe0.3Ge3, β = 0.337, γ = 1.244 and δ = 4.69 and for Mn4.5Fe0.5Ge3, β = 0.328, γ = 1.195 and δ = 4.64. The values of critical exponents obtained are found to be close to the 3D Ising universality class (β = 0.325, γ = 1.241, and δ = 4.82). Analyses based on the Renormalization group theory predictions reveal that the spin interactions are short-range extended types beyond the nearest neighbors due to the presence of a different set of Mn–Mn interactions with an unequal magnitude of exchange strengths in the Mn5−x Fe x Ge3 alloys.

A stable spherical MOF-derived Mnx-Fe2O3/C catalysts for low-temperature CO-SCR

A series of spherical Mnx-Fe2O3/C catalysts derived from MnFe-MOF-74 were fabricated via a sacrificing template method and applied for CO-SCR. Among the tested catalysts, Mn0.5-Fe2O3/C catalysts achieved a maximum NO conversion of 100 % in a broad temperature range between 225 and 500 °C, significantly higher than monometallic Fe2O3/C. Based on TPR, BET and XPS results, a redox reaction Fe3+ + Mn2+ ↔ Fe2+ + Mn3+ over Fe-O-Mn sites was constructed, which greatly facilitated the adsorption and activation of NO molecules. DFT calculations revealed that the incorporation of Mn obviously increased the local electron density of Fe-Mn sites not only resulting in a strong C-Fe/Mn and N-Fe/Mn bonding, but also effectively weaken the N-O bond. And the NO adsorption energy of Fe-O-Mn site over Mn doped α-Fe2O3 is −0.87 eV which indicates the stability of the adsorption configuration. Combined with the in situ FT-IR results, important intermediates Fe2+-(NO)22– and N2O were identified respectively at 1261 and 1358 cm−1, which were promoted by the synergistic interaction of Mn and Fe. This Mn-Fe synergistic interaction could contribute to lowering reaction barrier and boosting CO-SCR performance.

Facile Synthesis and Characterization of Novel Nanostructures for the Efficient Disposal of Crystal Violet Dye from Aqueous Media

An excessive accumulation of crystal violet dye in the human body results in an accelerated heart rate, tetraplegia, eye irritation, and long-term damage to the transparent mucous membrane that protects the eyeballs. Accordingly, in this paper, sodium manganese silicate/sodium manganese silicate hydroxide hydrate was easily fabricated as a novel type of nanostructures for the successful disposal of crystal violet dye from aqueous solutions. The formed sodium manganese silicate/sodium manganese silicate hydroxide hydrate nanostructures after the hydrothermal treatment of the gel produced from the interaction of Mn(II) ions with Si(IV) ions at 180 °C for 6, 12, 18, and 24 h were abbreviated as MS1, MS2, MS3, and MS4, respectively. The XRD showed that the average crystallite size of the MS1, MS2, MS3, and MS4 samples is 8.38, 7.43, 4.25, and 8.76 nm, respectively. The BET surface area of the MS1, MS2, MS3, and MS4 samples is 41.58, 46.15, 58.25, and 39.69 m2/g, respectively. The MS1, MS2, MS3, and MS4 samples consist of spherical and irregular shapes with average grain sizes of 157.22, 88.06, 43.75, and 107.08 nm, respectively. The best adsorption conditions of the crystal violet dye employing the MS1, MS2, MS3, and MS4 products were achieved at pH = 8, contact time = 140 min, and solution temperature = 298 kelvin. The linear pseudo-2nd-order model as well as the linear Langmuir isotherm better describe the disposal of the crystal violet dye using the MS1, MS2, MS3, and MS4 adsorbents. The studied thermodynamic parameters indicated that the disposal of the crystal violet dye employing the MS1, MS2, MS3, and MS4 adsorbents is spontaneous, exothermic, and chemical. The maximum disposal capacities of the MS1, MS2, MS3, and MS4 adsorbents towards crystal violet dye are 342.47, 362.32, 411.52, and 310.56 mg/g, respectively.

Effect of interaction degree between Mn and Ce of MnOX-CeO2 formulation on NO reduction and o-DCB oxidation performed simultaneously

MnOX-CeO2 catalysts were prepared by different methods in order to assess the influence of Mn and Ce interaction on the catalytic activity of NO reduction and 1,2-dichlorobencene (o-DCB) oxidation carried out simultaneously. Changes on catalytic properties were evaluated by XRD, Raman, N2-physisorption, H2-TPR and NH3-TPD. The samples prepared by co-precipitation and sol-gel exhibited the best catalytic activity over the whole temperature range. These preparation methods provide high interaction between Mn and Ce at surface and bulk, which was evidenced by the formation of mixed oxide phase. According to characterisation, the enhancement of catalytic activity with Mn and Ce interaction is associated to the promotion of structural defects, which improve redox and acid properties. Oxidative capability is also improved as a consequence of the oxygen vacancies generated by the presence of those structural defects. On the other hand, the promotion of Mn and Ce interaction favours the production of N2O in NO reduction at a lower temperature, and also leads to o-DCB total oxidation by decreasing CO production.