Effect Of Mn Substitution Research Articles

Effect of Mn substitution on the oxidation/adsorption abilities of iron(III) oxyhydroxides

In this study, divalent manganese ions [Mn(II)] were substituted a part of divalent iron ions [Fe(II)] present in Fe oxyhydroxides to prepare novel composites (Mn@Feox). The composites were prepared by (1) simultaneous hydrolysis of Fe(II) and Mn(II), and (2) rapid oxidation with H2O2. The resulting Mn@Feox prepared with different molar ratios of Fe and Mn was characterized and evaluated for their abilities to adsorb arsenic species [As(III) and As(V)] in aqueous solution. X-ray diffraction and field emission transmission electron microscope analyses revealed Mn@Feox has a δ-(Fe1−x, Mnx)OOH-like structure with their mineralogical properties resembling those of feroxyhyte (δ-FeOOH). The increase in Mn substitution in Mn@Feox enhanced the oxidative ability to oxidize As(III) to As(V), but it decreased the adsorption capacity for both arsenic species. The optimal Mn/Fe molar ratio that could endow oxidation and magnetic capabilities to the composite without significantly compromising As adsorption capability was determined to be 0.1 (0.1Mn@Feox). The adsorption of As(III) on 0.1Mn@Feox was weakly influenced by pH change while As(V) adsorption showed high dependence on pH, achieving nearly complete removal at pH 5.7. The adsorption kinetics and isotherms of As(III) and As(V) showed good conformity to pseudo-second-order kinetics model and Freundlich model, respectively.

Modified electrical properties of chemical solution deposited epitaxial BiFeO3 thin films by Mn substitution

The effect of Mn substitution on microstructure and electrical properties of epitaxial BiFeO3 (BFO) thin films grown by an all-solution approach was investigated. Raman analysis reveals that the Mn atoms substitution at Fe sites can result in Jahn-Teller distortion and thus lead to the weakness of long-range ferroelectric order. In addition, the break-down characteristics of BFO thin films are improved with the increase of Mn atoms content, although the leakage current is gradually increased. Meanwhile, the grain size, the dielectric constant and loss are also increased with the increase of Mn content. The P-E hysteresis loops and PUND results demonstrate that the intrinsic ferroelectric polarization is effectively improved with Mn atoms substitution as the grain size increased and Mn atoms play a role of nucleation sites. However, the ferroelectric properties are deteriorated with the excess substituted Mn content due to the higher leakage current.

Microstructure, enhanced piezoelectric, optical and magnetic properties of Mn substituted BiFeO3 film synthesized by chemical method

Very thin and high transparent manganese (Mn) substituted bismuth ferrite (BiFe1−xMn x O3—BFMO) (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) films deposited on the SnO2:F (FTO)/glass substrate were synthesized by chemical solution deposition technique. The effect of Mn substitution on the microstructure, piezoelectric, optical and magnetic properties was systematically investigated. X-ray diffraction and Raman spectra analysis revealed that the structure transition and lattice distortion of BiFeO3 (BFO) thin film occurred with Mn substitution. SEM images demonstrated that the average grain size of Mn substituted BFO thin film increased with increase of Mn substitution and EDS results confirmed the element composition with presence of Mn in the synthesized thin film. The piezoresponse of BFMO thin film increased with increase of Mn substitution and when Mn substitution x = 0.10, the maximum d33,eff reached to 41.81 pm/V, which is almost 125% higher than the pure BFO thin film. The transmittance and optical band gap decreased with increase of Mn substitution. The BFO thin film with Mn substitution x = 0.10 also showed a lower band gap of 2.64 eV. Furthermore, the Mn substituted BFO thin film show a much higher saturated magnetization compared to pure BFO thin film due to enhanced magnetically driven distortion of spiral spin cycloid induced by Mn substitution.

Effect of Mn substitution on structural and dielectric properties of bismuth ferrite

ABSTRACTBismuth ferrite (BiFeO3 or BFO) and manganese doped bismuth ferrite (BiFe1-xMnxO3, × = 0.1, × = 0.2) ceramic samples were fabricated using sol-gel processing technique. Pure phase BFO powder and its composites were obtained after annealing the as-prepared powder at 500°C. Ceramic samples were then fabricated by pressing in the form of circular discs followed by sintering at 550°C for 2 hours. The influence of Mn doping on structural, morphological and dielectric properties of BiFeO3 were studied and analysed. The frequency responses of dielectric constant (κ) and loss tangent (tanδ) have been investigated over a wide range of frequencies at room temperature.

Effect of Mn substitution for Co on the structural, kinetic, and thermodynamic characteristics of ZrCo1−xMnx (x=0–0.1) alloys for tritium storage

ZrCo1−xMnx (x = 0–0.1) alloys for tritium storage were prepared by induction levitation melting under an argon atmosphere. The effect of Mn substitution for Co on the alloy microstructure, initial activation behavior, hydrogen storage kinetics and thermodynamics was investigated. The results show that the ZrCo1−xMnx (x = 0, 0.025, 0.05) alloys have a single phase of ZrCo, while ZrCo1−xMnx (x = 0.075, 0.1) alloys consist of a main phase of ZrCo and a secondary phase of ZrMn2. It is observed that the initial activation time (uptake to 95% of saturated hydrogen capacity) decreases from 63.73 h to 0.24 h as the Mn content increases from x = 0 to x = 0.1. However, Mn substituted for Co is determined to result in disproportionation during activation and a loss in hydrogen capacity. For increasing Mn content in the alloy, the plateau width for Pressure-Composition-Temperature (P-C-T) curve is shortened, while the plateau pressure remains mostly unchanged. DSC measurements were also performed to investigate the thermal stability of the ZrCo1−xMnx system.

Effects of Mn substitution on crystal structure, magnetic and magnetocaloric properties of (Co1−xMnx)2B compounds

The crystal structure, magnetic and magnetocaloric properties of (Co1−xMnx)2B (x = 0.0, 0.1, 0.2, 0.25, 0.3, 0.35, 0.40) compounds were investigated by x-ray powder diffraction (XRD) and magnetization measurements. All compounds crystallize in a body-centred tetragonal single phase with the CuAl2-type structure. Due to the changes of lattice stability and ferromagnetic–antiferromagnetic exchange coupling interaction, the room temperature magnetization and the Curie temperature (TC) of (Co1−xMnx)2B compounds first increases at about x = 0.1 and then decreases with the substitution of Mn for Co. Second-order phase transition was confirmed based on the isothermal magnetization curves and the isothermal entropy change (ΔSM) was determined for the samples with x = 0.3, 0.35 and 0.4. The maximal magnetic entropy (|ΔSM|) under a field change from 0 to 5 T are found to be 2.49, 2.37 and 2.02 J kg−1·K for x = 0.3, 0.35 and 0.4, respectively. The corresponding relative cooling powers (RCP) are evaluated to be 59.74, 78.94 and 113.50 J kg−1. Given the low cost of Co, Mn and B, (Co1−xMnx)2B compounds may come as an base compound for a more efficient magnetocaloric material.

Effects of Mn substitution on thermoelectric properties of CuIn1−xMnxTe2**Project supported by the National Natural Science Foundation of China (Nos. 51632005 and 51371194) and National Basic Research Program of China (Grant No. 2013CB632500).

CuIn1 − xMnxTe2 samples have been synthesized by a melt-annealing method. The x-ray powder diffraction (XRD) analysis shows that the CuIn1−xMnxTe2 samples crystallize in the chalcopyrite phase. Mn doping can effectively optimize the electrical properties and accordingly improve the power factor. The room temperature electrical conductivity of doped CuInTe2 increases by several orders of magnitude due to substituting In with Mn. In addition, a large reduction in thermal conductivity is achieved through the enhanced phonon scattering via Mn-related point defects and precipitates. Therefore, an enhanced average ZT value up to 0.34 is achieved for sample CuIn0.925Mn0.075Te2, which is 41% higher than that of the pristine CuInTe2.

The investigation of the mechanical properties of Mn doped BaSnO3 nanoparticles

This study investigates the effect of Mn substitution on the structural and mechanical properties of nano BaSnO3 using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Scanning electron microscope (SEM) and Vickers microhardness. For this investigation, samples of type BaSn1-xMnxO3 with 0.04 ≤ x ≤ 0.4 were prepared by co-precipitation method. XRD patterns indicate the formation of single phase cubic structure BaSnO3 with space group (Pm3m) for 0 ≤ x ≤ 0.1. BaMnO2 hexagonal phase appears as impurity for x > 0.1. The crystallite size, increases as x increases. Vickers microhardness Hv was carried out at different applied loads varying between 0.98 N and 9.8 N at dwell time 40 seconds. The results show that Hv increases as the Mn-content increases, whereas it decreases as the applied load increase. The Hv results were analysed using Elastic Plastic Deformation and the Modified proportional specimen resistance models. The Vickers microhardness analysis indicates that Modified Proportional Specimen Resistance model is the most suitable one for describing the load independent microhardness region of the investigated samples.

Drastic effect of the Mn-substitution in the strongly correlated semiconductor FeSb2.

We report the effects of Mn substitution, corresponding to hole doping, on the electronic properties of the narrow gap semiconductor, FeSb2, using single crystals of Fe1−xMnxSb2 grown by the Sb flux method. The orthorhombic Pnnm structure was confirmed by powder X-ray diffraction (XRD) for the pure and Mn-substituted samples. Their crystal structure parameters were refined using the Rietveld method. The chemical composition was investigated by wavelength-dispersive X-ray spectroscopy (WDX). The solubility limit of Mn in FeSb2 is xmax ∼ 0.05 and the lattice constants change monotonically with increasing the actual Mn concentration. A drastic change from semiconducting to metallic electronic transports was found at very low Mn concentration at x ∼ 0.01. Our experimental results and analysis indicate that the substitution of a small amount of Mn changes drastically the electronic state in FeSb2 as well as the Co-substitution does: closing of the narrow gap and emergence of the density of states (DOS) at the Fermi level.

Perovskite-type LaFe1− x Mn x O3 (x=0, 0.3, 0.5, 0.7, 1.0) oxygen carriers for chemical-looping steam methane reforming: Oxidation activity and resistance to carbon formation

The effects of Mn substitution of LaMnxFe1−xO3 (x=0, 0.3, 0.5, 0.7, 1.0) on the oxidation activity and resistance to carbon formation for chemical-looping steam methane reforming (CL-SMR) were investigated. The desired crystalline perovskite phases were formed by transferring from the orthorhombic structure of LaFeO3 to rhombohedral lattice of LaMnO3 as the degree of Mn-doping increased. Manganese ions have a mixed state of Mn3+ and Mn4+ in the LaFe1−xMnxO3, meanwhile inducing the states of highly mixed character of Fe2+, Fe3+ and Fe4+ in iron ions. Substitution of Mn for Fe with proper value not only increases the lattice oxygen, which is conducive to the partial oxidation of CH4 to produce syngas, but also enhances the lattice oxygen mobility from the bulk to the surface of the oxygen carrier particles. Judging from the points of the redox reactivity, resistance to carbon formation and hydrogen generation capacity, the optimal range of the degree of Mn substitution is x=0.3–0.5.

Mn doping induced physico-chemical changes in La[sbnd]Ce ferrite nanofabricated by ionic liquid assisted hydrothermal route

Effect of Mn substitution on the structural, optical, surface and magnetic properties of mixed LaFeO3i.e. LaCe nanoferrites (La0.9Ce0.1Fe1-xMnxO3) synthesized by hydrothermal route using ionic liquid surfactant (ILS), 1-hexadecyl-3-methyl imidazolium chloride, [C16mim][Cl], have been explored by X-ray diffraction (XRD), IRaman spectroscopy, Brunauer-Emmett-Teller (BET) adsorption isotherm, Vibrating sample magnetometer (VSM) and Mӧssbauer spectroscopy etc. Incorporation of Mn in crystal lattice of LaCe ferrite induced the structural distortion as specified by structural studies. Morphology and the size of the obtained nanoparticles (NPs) get slightly altered by the quantity of dopant as observed from transmission electron microscopy (TEM). The appearance of rod shaped morphology along with spherical NPs indicates the templating effect of ILS. Surface and magnetic properties of Mn doped LaCe NPs have found to be significantly improved than that of undoped LaCe ferrites. Magnetization of the obtained NPs strongly depends on the content of Mn in the lattice. Enhanced magnetization has been observed up to certain extent of Mn doping (x = 0.3). At higher Mn content (x = 0.5), a significant reduction in magnetization has been observed as revealed from Mӧssbauer and magnetic studies. The enhanced surface area (36.18 m2/g) of the Mn doped samples over the undoped LaCe ferrite opens the new doors in biological and sensing applications.

Evaluation of Fe Substitution Effect on the Electrochemical Properties of LiMnPO4 By Single Particle Measurement

Introduction Lithium ion batteries (LIB) have been widely used as power sources for portable electronic devices such as laptop computers and cellular phones due to their high energy density. A battery research has been become more important issue for large scale applications such as EVs and HEVs. LiMnPO4 has been focused as a promising cathode material to realize high performance of LIB. So far, many approaches have been done to improve the electrochemical properties of LiMnPO4 by carbon coating, cation doping and so on. An electric and Li+ conductivities of LiMnPO4 are intrinsically low. The Mn substitution with Fe has been done as one of effective approaches to improve the electrochemical properties of LiMnPO4. However, its substitution effect has not been fully understood. The conventional evaluation method using composite electrodes has some difficulties due to porous structure of composite electrode. Therefore, we have conducted a single particle measurement using one active material particle (mainly secondary particle) or a composite particle obtained by taking out a part of composite electrode. We have reported to reduce an influence of the electrode structure on the electrochemical response by using single particle measurement (1). A phosphate-based cathode materials have an excellent thermal stability. These materials are promising active materials for large batteries. However, a slow electrochemical reaction of LiMnPO4 should be improved to obtain high rate capability. A Fe substitution for LiMnPO4 has improved its rate capability (2). In this study, we synthesized carbon-coated LiFexMn1-xPO4. A single particle measurement was employed to understand the intrinsic effect of Mn substitution with Fe on the electrochemical properties of LiMnPO4. Experimental Li2SO4, MnSO4•5H2O, FeSO4•7H2O, (NH4)2HPO4, and carboxymethyl cellulose (CMC) were used as starting materials to synthesized carbon coated LiFexMn1-xPO4 by hydrothermal method. The hydrothermal treatment was performed at 200 ºC for 3 h. The reaction product was dried and then grounded with planetary ball mill (400 rpm, 1 hour × 10 times) to obtain fine powder. The obtained powder was then heated at 700 ºC for 1 h under 97% Ar + 3% H2 atmosphere for a graphitization of CMC on particle surface to obtain LiFex Mn1-xPO4/C. A small composite particle used for single particle measurement was obtained by stripping from the composite electrode with a weight ratio of LiFexMn1-xPO4/C: AB: PVdF = 85: 10: 5 on aluminum current collector. Au micro-electrode with 10 mm diameter was attached to a LiFexMn1-xPO4/C composite electrode particle in an electrolyte (1 mol dm-3 LiPF6 / EC : EMC = 3 : 7 in vol.) using a micromanipulator under optical microscope observation. All the experiments were carried out under Ar atmosphere to remove the effect of water and oxygen. Results and discussion Figure 1 shows the XRD patterns of LiFexMn1-xPO4 synthesized by hydrothermal method. All peaks are attributable to olivine structure of LiFexMn1-xPO4, suggesting that the synthesized LiFexMn1-xPO4 samples are single phase without impurity. The Fe substitution in LiMnPO4was also confirmed from Rietveld analysis. Figure 2 shows the rate capabilities of LiFexMn1-xPO4/C composite electrode particles by single particle measurement. Discharge capacities at 1.5 C and 15 C were plotted against x in LiFexMn1-xPO4/C. In single particle measurement, in order to normalize a variation of particle size, the capacities were indicated by depth of discharge (DOD). The capacity retention at 15 C was improved with increasing amount of Fe substitution. A comparison of discharge curves for each composite particle, a potential plateau corresponding to Mn2+/3+ appeared at more noble potential with increasing of Fe substitution amount. The improvement of rate capability may be due to the improved electronic conductivity and suppressed Jahn-Teller deformation of Mn by Fe substitution. Reference [1] H. Munakata, K. Annaka, K. Kanamura, The 81th Electrochemical Society of Japan, p.343(2Q01). [2] Seung-Min Oh et al , J. Power Sources 196 (2011) 6924-6928 Figure 1

Effects of Mn doping on dielectric and ferroelectric characteristics of lead-free (K, Na, Li)NbO3 thin films grown by chemical solution deposition

High-quality lead-free piezoelectric xMn-doped (K0.48Na0.52)0.985Li0.015NbO3 films (KNLN; x = 0, 0.01, 0.02, 0.03) were successfully deposited onto Pt(111)/Ti/SiO2/Si(100) substrates by sol–gel method. Effects of Mn substitution on the microstructure, dielectric properties, ferroelectric properties, and leakage current of the KNLN films were investigated in detail. Mn-doping can significantly improve the ferroelectric properties and decrease the leakage current of KNLN films. Optimal dielectric properties were obtained in films doped with 2 mol% Mn, whose dielectric constant and dielectric loss at 1 kHz were 875 and 0.030, respectively. In addition, well-saturated ferroelectric P-E hysteresis loop with large remanent polarization (2Pr) and coercive field (Ec) of 22.5 μC/cm2 and 65 kV/cm were obtained in 2 mol% Mn-doped KNLN film at an applied electric field of 200 kV/cm.

Magnetic and Dielectric Investigations of Mn-Doped Ba Hexaferrite Nanoparticles by Hydrothermal Approach

A hydrothermal method followed by heat treatment was used to synthesize Mn-substituted Ba2Co2−x Mn x Fe12O22 nanoparticles with a nominal chemical composition of $$ 0 \le x < 1 $$ and step gap of 0.3. In this study, the effect of Mn substitution on Co2Y-type barium hexaferrite is investigated after employing x-ray diffraction for crystal structure, field emission scanning electron microscopy for morphology, energy dispersive analysis of x-ray spectroscopy for elemental composition, Fourier transform infrared spectroscopy to confirm bond modes, and vibrating sample magnetometry for magnetic measurements. It was found that the sample at x = 0.9 is of particular interest due to its large coercivity and anisotropy. Later on, for x = 0.9, temperature-dependent magnetic analyses including hysteresis loops, zero-field-cooled, and field-cooled at a particular field of 100 Oe were performed. The decreasing trend in saturation magnetization with increase in temperature was estimated. On the other hand, first an increase and then decrease in coercivity values were observed. These loops also revealed dependence of coercivity on magneto-crystalline anisotropy and average crystallite size of nanoparticles. Dielectric measurements at x = 0.9 make it suitable for high frequency applications.

Structural and magnetic response of Mn substituted Co2 Y-type barium hexaferrites

In present work, a series of Ba2Co2−xMnxFe12O22 nanoparticles (x = 0.0, 0.1, 0.3, 0.5, 0.7, and 0.9) has been synthesized by hydrothermal method. Effect of Mn substitution on structural, microstructure and magnetic properties has been investigated in detail. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analyses confirmed the formation of Y-type hexagonal ferrite structure. Morphology and chemical composition studies performed by Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy conformed that with increasing Mn concentration grain size increases from few nanometers to micrometer range. Furthermore, magnetic analyses revealed that with increasing Mn concentration at octahedral and tetrahedral sites the coercivity and squareness were found to increase from 455Oe to 2550Oe, and 0.26 to 0.56, respectively. Theoretical approach was also used to calculate saturation magnetization of synthesized samples. The synthesized nanoparticles with enhanced magnetic characteristics are ideal candidate for their use in perpendicular magnetic recording and high frequency applications.

Systematic study on surface and magnetostructural changes in Mn-substituted dysprosium ferrite by hydrothermal method

Dysprosium iron garnets are of scientific importance because of the wide range of magnetic properties that can be obtained in substituting dysprosium by a rare earth metal. In the present work, the effect of Mn substitution on magnetostructural changes in dysprosium ferrite nanoparticles is studied. Highly crystalline pure and Mn doped dysprosium ferrite nanoparticles were synthesized by hydrothermal method. The samples were calcined at 1100°C for 2h in air atmosphere which is followed by characterization using XRD, FT-IR analysis, SEM, XPS and VSM. The average crystallite size of synthesized samples were calculated by X-ray diffraction falls in the range of 88.4–86.8nm and was found to be in cubic garnet structure. For further investigation of the structure and corresponding changes in the tetrahedral and octahedral stretching vibrational bonds, FT-IR was used. The synthesized samples consist of multiple oxidation (Fe3+ and Fe2+) states for Fe ions and (Mn3+ and Mn2+) Mn ions analyzed in three ways of Fe 2p and Mn 2p spectra from the XPS analysis. With respect to Mn dopant in Dy3Fe5O12, the cationic distributions of elements were discussed from high resolution XPS spectra by peak position and shift, area, width. To find out the porous/void surface morphology of the sample, scanning electron microscopy was used. From XPS analysis, the presence of elements (Dy, Mn, Fe and O) and their composition in the prepared samples were confirmed. Further, the role of dopant on the magnetic properties of the dysprosium ferrite nanoparticles was also observed from VSM which shows the ferromagnetic behavior. It was concluded that the magnetic properties of synthesized nanoparticles mainly depended on the oxidation state of elements, cationic distribution and crystallinity.

Effect of Mn substitution on structural and magnetic properties of ferromagnetic shape memory alloys

ABSTRACTThe structure and the magnetic transitions have been investigated as a function of Mn in stoichiometric Ni2MnGa heusler alloys. Particular attention is paid to examine the linear increase of martensite transformation temperature on substituting Mn for Ga. It is observed that the martensite temperature increases and Curie temperature decreases with the effect of Mn content. Room-temperature magnetic measurements show the composition-dependent characteristics with decreasing magnetic saturation values and increasing coercivity values due to decrease in the magnetic exchange interaction strength with increasing Mn in place of Ga. The scanning electron microscopy image confirms that the Mn-rich alloys have the martensitic plates.

Manganese doped Sm–Cd nanoalloys–their synthesis, characterisation and evaluation of electrical properties

Manganese doped Sm–Cd nanoparticles with manganese content varying from 0 to 30 mol % were synthesized using chemical reduction method. The structural and compositional analyses were carried out using x-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis indicated the formation of single phase cubical structure of all the samples. The crystallite size was observed to vary from 47 to 21 nm as the manganese content was increased. The effect of Mn substitution on the frequency and temperature dependent electric properties (dielectric constant, dielectric & tangent loss) of Sm–Cd nano alloys with nominal composition Sm11Cd45-x Mnx (where x = 0.0, 20, 25 and 30) was measured. The increase in AC conductivity with frequency may be attributed to the tremendous increase of mobility of the charge carriers. DC conductivity linearly decreases with temperature indicating metallic behavior of nano alloys. The room temperature conductivity of the materials increases from 6.2 × 10−5 to 1.37 × 10−4 S/cm with the increase in Mn content.

Synthesis and Electrochemistry of Na2.5(Fe1−yMny)1.75(SO4)3 Solid Solutions for Na‐Ion Batteries

AbstractNa2+2xFe2−x(SO4)3 was recently reported as a promising cathode material for Na‐ion batteries with high voltage generation (3.8 V vs. Na/Na+), high energy density, and extreme high‐rate operation, making it competitive to lithium battery cathodes. Following our identification of the narrow off‐stoichiometric region in Na2+2xFe2−x(SO4)3 solid solutions (x around 0.25), we report here the effect of Mn substitution in Na2.5(Fe1−yMny)1.75(SO4)3 (y=0, 0.25, 0.5, 0.75, and 1.0) solid solutions when increasing the voltage of the Fe3+/Fe2+ redox couple, but with a simple capacity decrease, owing to the entire Mn2+ inactivity.

Effect of Mn substitution on the promoted formaldehyde oxidation over spinel ferrite: Catalyst characterization, performance and reaction mechanism

The work reports the synthesis and characterization of manganese substituted spinel ferrites, and their application as catalysts for formaldehyde oxidation. Structure and cationic coordination environment of the prepared catalysts were investigated by XRD, Raman, XPS spectroscopy and TG-DSC analysis. Temperature-programmed reduction (TPR) was used to measure the reducibility of catalysts. The characterization results reveal the formation of spinel structure in all the synthetic catalysts. The Mn cations enrich on the surface in the valence of +3 and +4. Mn substitution obviously increases the lattice oxygen content, facilitates the reduction of ferrite, and enhances the oxidative ability of Fe3+ and Mn cations on the catalyst surface. The presence of Mn cations in spinel ferrite greatly improves its catalytic activity in formaldehyde oxidation, evidenced by the obvious decrease of 90% formaldehyde conversion temperature. The studied catalyst also displays high stability and superior activity in the presence of water vapor, which presents an applied interest. The remarkable effect of Mn substitution on the promoted formaldehyde oxidation over spinel ferrite catalysts was discussed in view of reaction mechanism and variations in microstructural environment and physicochemical properties of spinel ferrite.