Oxide LaFeO3 Research Articles

Efficient Formaldehyde Gas Sensing Performance via Promotion of Oxygen Vacancy on In-Doped LaFeO3 Nanofibers.

Perovskite oxide LaFeO3(LFO) emerges as a potential candidate for formaldehyde (HCHO) detection due to its exceptional electrical conductivity and abundant active metal sites. However, the sensitivity of the LFO sensor needs to be further enhanced. Herein, a series of LaxIn1-xFeO3 (x = 1.0, 0.9, 0.8, and 0.7) nanofibers (LxIn1-xFO NFs) with different ratios of La/In were obtained via the electrospinning method followed by a calcination process. Among all these LxIn1-xFO NFs sensors, the sensor based on the L0.8In0.2FO NFs possessed the maximum response value of 18.8 to 100 ppm HCHO at the operating temperature of 180 °C, which was 4.47 times higher than that based on pristine LFO NFs (4.2). Furthermore, the L0.8In0.2FO NFs sensor also exhibited a rapid response/recovery time (2 s/22 s), exceptional repeatability, and long-term stability. This excellent gas sensing performance of the L0.8In0.2FO NFs can be attributed to the large number of oxygen vacancies induced by the replacement of the A-site La3+ by In3+, the large specific surface area, and the porous structure. This research presents an approach to enhance the HCHO gas sensing capabilities by adjusting the introduced oxygen vacancies through the doping of A-sites in perovskite oxides.

Influence of doped ions on the electrochemical hydrogen storage properties of LaFeO3-based solid solutions

Perovskite oxides LaFeO3 has been considered as one of the most promising candidates as the negative electrode material of Ni/MH batteries, due to its advantages such as low cost, outstanding corrosion resistance and environmentally friendly. Nevertheless, the low electrical conductivities and poor specific capacities are the main obstacles of developing this material to practical application. Doping is an effective method to solve these problems. In this paper, nanosized LaFeO3-based solid solutions doped with Co3+, Mn3+, and Li+ ions were synthesized via sol-gel method, and the contents of the doped ions are set as 0.10. The substitution positions of the doped ions were discussed. The microstructure tests revealed that the doped samples were single phase structures, and the crystallite sizes of the doped samples were smaller than that of the undoped LaFeO3. The dispersion degrees of the doped samples were improved. The results of the spectra tests demonstrated that the doped ions decreased the band gap energies, the Co3+ and Mn3+ ions influenced the frequencies of Fe–O stretching vibrations, and partial replacement of La3+ ions by Li+ ions induced the shift of vibration modes of the La–O bond. Electrochemical hydrogen storage measurements showed that the doped samples possess significantly better properties than that of the undoped LaFeO3. Thereinto, the maximum discharge capacity of the Co3+ ion doped sample reached to 414 mAh/g at the 14th cycle and remained stable at around 400 mAh/g within the following cycles. Kinetic results further proved that the doped samples showed better performances. The hydrogen storage properties of doped LaFeO3 are closely associated with the contents of the oxygen vacancies and defects in the lattice of samples. In addition, the characteristics of the doped ions also play important roles in improving the hydrogen storage properties of the LaFeO3-based oxides.

Structural, optical analysis, stress-strain, and dielectric properties of selenium oxide/LaFeO3/blend nanocomposites with tunable properties for optoelectronics and micro-supercapacitors

This work focuses on developing flexible nanocomposites by introducing two types of ceramic nanofillers into a biopolymeric blend for optoelectronic and energy-storing applications. Selenium oxide (SeO2) nanoparticles (NPs) and LaFeO3 NPs were prepared by hydrothermal and solid-state reactions, respectively, and incorporated into the polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) through the solution casting process. Transmission electron microscope and X-ray diffraction tests revealed the creation of hexagonal SeO2 and orthorhombic LaFeO3 NPs, with average sizes of 17 and 93 nm. The blend's degree of crystallinity was dependent on SeO2 NPs and LaFeO3 contents. The infrared absorption spectra revealed the interactions/complexation of the fillers with the blend reactive groups. The scan e-microscope (field emission mode) investigated the films' surface morphology and detected the elements they contain. LaFeO3/SeO2 content impacted stress-strain behavior, raised the tensile strength from 64 to 70.9 MPa, and dramatically lowered the strain at break and toughness. UV–vis-NIR measurements exhibited that the transmittance, extinction coefficient, and refractive index can be tuned by SeO2 and LaFeO3/SeO2 content. The direct (Eg.d)/indirect (Eg.id) band gaps were reduced from 5.25/4.9 eV to 4.95/4.7 eV. The dielectric parameters (constant, loss, energy density, and conductivity) were significantly increased after loading 5.0 wt% LaFeO3/SeO2. The dielectric moduli and Cole-Cole plots were also investigated. The structural modifications and enhancement of the optical features and dielectric parameters make the resulted samples the best candidates for optoelectronic devices and energy-storing applications such as sensors and supercapacitors.

Synthesis of Lanthanum Ferrite Perovskite Nanoparticles: An Alternative Bio‐Approach Versus a Conventional Chemical Approach

AbstractHerein, we report the synthesis of perovskite‐type oxide LaFeO3 nanoparticles via chemical as well as bio approaches. Azadirachta indica (neem) extract's impact on the LaFeO3 nanoparticles has been studied to identify potential substitutes for detrimental chemical synthesis. The X‐ray diffraction (XRD) examinations of synthesized perovskites by both routes reveal the cubic LaFeO3 phase and identical crystallographic patterns. The optical bandgap energies (Eg) for the chemical and bio‐synthesized variants are determined to be 2.05 and 2.03 eV, respectively using UV–visible (UV–vis) spectroscopy. Fourier transform infrared spectroscopy (FTIR) analysis affirms the occurrence of two significant vibrational bands at 558 and 438 cm−1, which strengthen the formation of perovskite LaFeO3. Field emission scanning electron microscopy (FE‐SEM) investigation indicates the chemical variant has larger blockier‐shaped particles, whereas the bio‐synthesized sample has a micro‐spherical morphology with sharp edges. The X‐ray photoelectron spectroscopy (XPS) investigations substantiate the chemical state of La‐3d, Fe‐2p, and O‐1s present in both variants, which comprises the 3 : 3 perovskite type. Vibrating Sample Magnetometry (VSM) analysis elucidates weak ferromagnetism at room temperature in both of the synthesized samples. The novelty of this work concentrates on divulging that green synthesized LaFeO3 perovskites are more environmentally benign and affordable than chemically synthesized ones.

A novel sheet perovskite type oxides LaFeO3 anode for nickel-metal hydride batteries

Compared with traditional hydrogen storage alloys, perovskite oxide LaFeO3 materials are considered as one of the most promising anode materials for nickel-metal hydride batteries owing to their low cost, environmental friendliness, and superior temperature resistance. However, the biggest problem faced by perovskite oxide LaFeO3 as an anode material for Nickel/metal hydride (Ni-MH) batteries is the low electrical conductivity and poor specific capacity, which is mainly due to the serious agglomeration phenomenon in its structure. To solve the above problems, lamellar LaFeO3 material with large specific surface area and small particle size has been synthesized by adding N,N-Dimethylformamide (DMF) and polyvinyl pyrrolidone (PVP) inhibitor materials to the precursor. By changing the sintering temperature, the lamellar composite LaFeO3 material can be controlled. Consequently, the maximum discharge capacity of lamellar LaFeO3 is up to 372.1 mA h g–1 at the discharge current density of 60 mA g–1. Meanwhile, after 100 cycles, the specific discharge capacity of the lamellar LaFeO3 can still reach 293.1 mA h g–1, which is much higher than that of 98.5 mA h g–1 for LaFeO3. In addition, the kinetics of LaFeO3 has been investigated and the lamellar LaFeO3 shows excellent dynamic properties. Notably, the exchange current density I0 (300 mA g–1) of the layered LaFeO3 electrode is higher than that of LaFeO3 (150 mA g–1). Overall, this work provides insights into a structure-performance relationship for the further development of high-performance perovskite-type oxide nickel-metal hydride battery anodes.

Enhancing Electrochemical CO2 Reduction of La(Sr)Fe(Mn)O3 with Metal (Ru, Ni, Co, and Fe) Catalytic Additives for High-Temperature CO2 Electrolysis Cells

Solid oxide electrolysis cells (SOEC) have tremendous potential as highly efficient devices for high-temperature CO2 electrolysis. Commonly used Ni-based fuel electrodes experience inherent redox instabilities under direct CO/CO2 conditions. Therefore, the robust perovskite oxide La(Sr)Fe(Mn)O3 (LSFM) has been suggested as an alternative owing to its excellent coking resistance. However, LSFM electrodes are limited by their poor catalytic activity in CO2 reduction. To alleviate this problem, various metal additives have been added as catalysts to decrease the surface reaction barrier, which accelerates the chemical adsorption of CO2. In this study, the various metal catalysts (Ru, Co, Fe, and Ni) are deposited on the surface of LSFM electrode using the infiltration method. The distribution of the relaxation time (DRT) is investigated to confirm the catalytic activity for CO2 electrolysis. Consequently, when applied Fe catalyst in LSFM electrode, an electrolysis performance of 2.2 A cm-2 at 1.5 V in CO2 electrolysis was obtained at 1123 K.

Surface modification of perovskite‐type oxide LaFeO3 with electroless nickel deposition for application in MH‐Ni batteries

AbstractIn this study, the perovskite‐type oxide LaFeO3 is treated by electroless Ni deposition with different reaction time and the electrochemical properties of the resulting material are investigated as the anode for MH‐Ni batteries. XRD, SEM, and TEM measurements reveal a uniform deposition of crystalline nickel on the oxide surface and a clear increase in the amount of Ni coating with the deposition time. The electrochemical analysis shows that the electroless deposition can significantly improve the maximum discharge capacity of the battery. Furthermore, the coated electrodes exhibit excellent activation performance and superior cyclic stability. With the increase in the reaction temperature, improvements in the discharge ability, exchange current density, and diffusing coefficient of hydrogen are also observed.

Catalytic gas nitriding of M50NiL steel by LaFeO3 pervoskite oxide under low-pressure conditions

To generalize the application of the LaFeO3 oxide in catalytic nitriding of steels, the M50NiL steel, a typical high-alloy bearing steel, was nitrided under low-pressure conditions. The catalytic effect of the LaFeO3 oxide on nitriding kinetics of M50NiL steel was evaluated and a new understanding of the catalytic mechanism was proposed. The microstructure, phase composition, surface morphologies and depth of nitrided layers were characterized by optical microscope, X-ray diffraction, scanning electron microscope and microhardness tester, respectively. The wear resistance of nitrided layers was evaluated by a pin-on-disk wear tester and the chemical bonds on nitrided surfaces were identified by X-ray photoelectron spectroscopy to analyze the process of nitriding reactions. The results show that the LaFeO3 catalytic nitriding was suitable for M50NiL steel. The LaFeO3 catalytic nitriding could dramatically improve the toughness of nitrided layer via the suppression of nitrides formation. The adsorption and decomposition of NHx species on the LaFeO3 oxide were alternatively occurred on La-O terminated surfaces and Fe-O terminated surfaces, resulting in the fluctuate nitrogen concentration and rapid diffusion of active nitrogen atoms. The nitriding kinetics greatly depended on the oxidation state of nitrided surfaces. Namely higher oxidation capacity corresponded to higher nitriding efficiency.

Optimizing La1-xSrxFeO3-δ electrodes for symmetrical reversible solid oxide cells

Reversible solid oxide cells (RSOCs) are prone to material thermal property mismatching problems between electrodes and electrolyte, which greatly reduces their energy efficiency and causes irreversible performance degradation. One solution is to develop symmetrical RSOCs (SRSOCs) employing identical electrode materials to effectively address thermal property mismatching related issues and also simplify the manufacturing process. Herein, La1-xSrxFeO3-δ (x = 0–0.20) perovskites are developed and applied as both fuel and air electrode materials for SRSOCs for the first time. The impact of Sr substitution for La on the crystal structures, conductivities and electrochemical performance of LaFeO3 oxides is systematically investigated. It is found, after doping with Sr, overall properties of the LaFeO3 oxides show an obvious improvement, especially for the sample of La0·9Sr0·1FeO3-δ (LSF9010). The peak power density of SRSOCs featuring LSF9010 can stand at 0.575 W cm−2 at 800 °C under the solid oxide fuel cell (SOFC) working model. Under solid oxide electrolysis cell (SOEC) model, the current density stands at 0.84 A cm−2 at 800 °C and 1.5 V. More importantly, the La0·9Sr0·1FeO3-δ symmetrical cell can operate steadily for 128 h under SOFC mode and 25 h under SOFC-SOEC cycle mode, respectively, with almost no performance degradation found. The outcomes of the current study show that the developed LSF9010 may be used as an outstanding multifunctional electrode material in SRSOCs.

Charge-transfer effect in Fe 2p core-level x-ray photoemission spectra of trivalent Fe oxides: LDA + DMFT study

Motivated by recent hard x-ray photoemission spectroscopy (XPS) experiment for trivalent Fe oxides Sr2FeMoO6 (ferrimagnetic correlated metal) and LaFeO3 (antiferromagnetic Mott insulator) (Phuyal et al 2021 J. Phys. Chem. C 125 11249–56), we present a theoretical analysis of the Fe 2p core-level spectra using a computational method based on local density approximation combined with dynamical mean-field theory. We find that a nonlocal screening (NLS) effect in the XPS final states is crucial for interpreting the experimental XPS result of both the Fe oxides. A close relationship between the NLS feature in core-level spectra and a long-range magnetic ordering is emphasized.

Mesoporous LaFeO3 nanoparticles decorated onto activated carbon from agricultural paste (Synthesis, characterization and adsorption properties)

This work reports study of structure, magnetic and adsorption properties of LaFeO3 nano particles decorated on the surface of activated carbon. Activated carbon was prepared from sugar beet residue as an agricultural waste material (ACS). The perovskite-type oxide LaFeO3 nanoparticles were prepared by sol-gel (pechini) method using citric acid. The LaFeO3 was decorated on the surface ACS. The structure of samples was studied by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET). The surface morphology was considered by field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS) methods. The XRD results showed LaFeO3 nanoparticles have orthorhombic structure (space group continued to be Pnma. No. 62) of LaFeO3 perovskite did not change even when it was decorated onto ACS. VSM vibrating of samples was determined. The weak ferromagnetic behavior with specific saturation magnetization of 1.18 and 0.6 emu/g was observed at 15 kOe for LaFeO3 and LaFeO3 nanoparticles decorated onto ACS, respectively. Crystal violet (CV) dye was used as a model of pollutant. At contact time of 60 min and pH of 7 the highest percent of CV was observed. The maximum adsorption capacities of CV removal by ACS, LaFeO3 and LaFeO3 decorated on ACS was obtained, respectively. The adsorption kinetic of CV removal was followed by pseudo-second order model. Thermodynamic parameters of adsorption process of CV showed the endothermic and spontaneous processes. The LaFeO3 was decorated on the ACS was examined for real wastewater and 75% of dye removal was obtained.

LaFeO3 perovskite nanoparticles for efficient capture of elemental mercury from coal-fired flue gas

LaFeO3 perovskite was synthesized by sol–gel method and calcination method and used to remove mercury in flue gas. Three kinds of metal oxides La2O3, Fe2O3, and LaFeO3 were evaluated. The results indicated that the performances for Hg0 removal decreased in the order of LaFeO3 > Fe2O3 > La2O3. LaFeO3 has ∼94% removal efficiency at 120 ℃. To explore the temperature response range and the influence of simulated flue gas, the performance of LaFeO3 to remove Hg0 under O2, NO, SO2, and different temperature conditions was further examined. Furthermore, LaFeO3 is repeat-ability. The characterization results showed that the Hg0 transition to HgO is due to the valence change of iron and the release of lattice oxygen. In addition, density functional theory (DFT) was conducted to calculate the density of states to verify the performance of the sample. This work shows that LaFeO3 is a promising adsorbent for mercury removal from flue gas in coal-fired power plants.

Electrochemical Charge and Discharge Performance of Perovskite-Type Oxide La1−x Na x FeO3 (x = 0–0.8) in Alkaline Solution

LaFeO3 as a new negative electrode material for nickel-hydrogen batteries used as energy storage has the advantages of high capacity, advanced temperature resistance, and low cost. However, its conductivity and dynamic performance are poor, seriously hindering its applications. In light of increasing concentration of oxygen vacancies and improving conductivity after replacing A-site elements of the material, here we synthesize low-priced Na doping LaFeO3 oxides, La1−x Na x FeO3 (x = 0–0.8), as the negative electrode by a solid-state reaction method. Studies show that doping Na can reduce particle aggregation, thus helping to increase the surface area of LaFeO3. Therefore, its discharge capacity remarkably increases to 356.7 mAh g–1 (x = 0.6) from 178.8 mAh g–1 (x = 0) at 60 °C, which also maintains 73.4% after 100 cycles for La0.4Na0.6FeO3, elevated by 55.1% compared to LaFeO3. In addition, the high rate discharge ability of an La0.4Na0.6FeO3 electrode at a discharge current density of 1500 mA g–1 reaches 30.7% in contrast to 11.2% for undoped LaFeO3. As such, the La0.4Na0.6FeO3 material with superior cycling capacity is proven to be a more promising electrochemical hydrogen storage electrode compared to LaFeO3, which greatly increases the practical application value of the material.

The electronic properties and structural stability of LaFeO3 oxide by niobium doping: A density functional theory study

The niobium doping perovskite has been used in anode materials of solid oxide fuel cell. The electronic properties and structural stability of LaFeO3 (LFO) oxide by Nb-doping and the adsorption of H2 molecule at the clean and Nb-doped LFO (001) surface are investigated by theoretical calculations. The calculated results reveal that the band gap of the orthorhombic LFO is 2.04 eV and the gap disappears after the Nb-doping, which improves the electrical conductivity. The Nb-doping increases the formation energy of oxygen vacancy in orthorhombic LFO. The calculated results of binding energy and formation enthalpy imply that the structural stability is strengthened after Nb-doping, which provides a theoretical explanation for recent experimental observations. This result can be attributed to the change of electronic structure after the Nb-doping. The bond mechanisms for LFO and Nb-doped LFO are obtained by analyzing density of states, Mulliken charges and bond population. Based on adsorption properties, it can be found that the adsorption of H2 molecule is slightly enhanced after Nb-doping and the Nb-doping facilitates that H2 molecule dissociates to H atoms. These results could provide powerful interpretations for the origin of experimental phenomenon.

Effect of elemental doping on the catalytic activity of ABO3 perovskite oxides during low-pressure gas nitriding

In order to optimize the catalytic activity of the LaFeO3 oxide during low-pressures gas nitriding, the elemental doping by chromium, nickel and cerium was applied in the present work. The effects of doped LaFeO3 oxides on catalytic nitriding efficiency were systematically investigated. A new catalytic feature was proposed to explain the differences in catalytic activity among ABO3 oxides. The microstructure, phase composition and thickness of nitrided layers were characterized by the optical microscope, scanning electron microscope, X-ray diffraction and micro-hardness tester, respectively. The chemical bonds on nitrided surfaces were carefully investigated by X-ray photoelectron spectroscopy. The first-principles calculation was applied to reveal the inner diffusion behavior of nitrogen atoms. The results show that all ABO3 oxides exhibit an excellent catalytic activity in low-pressure gas nitriding. The LaFeO3 and (La0.5Ce0.5)FeO3 oxide show the enhanced catalytic activity as nitriding time prolonging while the LaCrO3 and LaNiO3 oxide present an opposite phenomenon. It depended on the state of active oxygen on nitrided surfaces, which is affected by the valence of doped elements. A critical ratio of adsorbed oxygen to hydroxyl on nitrided surfaces was proved to be 1.33. Beyond this value, ABO3 oxides have a remarkable improvement on catalytic nitriding.

Mn-doped perovskite-type oxide LaFeO3 as highly active and durable bifunctional electrocatalysts for oxygen electrode reactions

Perovskite oxides based on the alkaline earth metal lanthanum for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline electrolytes are promising catalysts, but their catalytic activity and stability remain unsatisfactory. Here, we synthesized a series of LaFe1−xMnxO3 (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1) perovskite oxides by doping Mn into LaFeO3 (LF). The results show that the doping amount of Mn has a significant effect on the catalytic performance. When x = 0.5, the catalyst LaFe0.5Mn0.5O3 (LFM) exhibits the best performance. The limiting current density in 0.1 mol·L−1 KOH solution is 7 mA·cm−2, much larger than that of the commercial Pt/C catalyst (5.5 mA·cm−2). Meanwhile, the performance of the doped catalyst is also superior to that of commercial Pt/C in terms of the long-term durability. The excellent catalytic performance of LFM may be ascribed to its abundant O2−/O− species and low charge transfer resistance after doping the Mn element.

Investigation on Gas Sensing Properties and SVM Training of Perovskite Metal Oxide LaFeO3 Microsphere

Perovskite oxides have attracted extensive attention due to their excellent photoelectric properties in recent years. In this paper, LaFeO3 (LFO) perovskite microsphere were synthesized by simple hydrothermal synthesis with iron nitrate and lanthanum nitrate as metal sources and citric acid as complexing agent. The microstructure and crystal structure of perovskite nanomaterials were characterized by SEM and XRD. The LaFeO3 perovskite type gas sensor was manufactured and its gas-sensitive characteristics were studied. The results show that LaFeO3 sensor has good gas-sensitive performance to ethanol whose response reaches about 15 at 250℃, and has excellent selectivity and recovery ability. In addition, in the concentration gradient test, the support vector machine in mathematical theory was used for training and recognition, and the result shows that the recognition rate could reach 100%. Figure 1

Catalytic behavior of LaFeO3 pervoskite oxide during low-pressure gas nitriding

The LaFeO3 perovskite oxide has been proved to be an effective catalyst in the gas nitriding. However, its catalytic efficiency was sensitive to the nitriding parameters. In order to clarify the catalytic conditions of the LaFeO3 oxide, the low-pressure gas nitriding was carried out in the present work. The effects of gas pressure and ammonia flow rate on catalytic behavior of the LaFeO3 oxide were discussed. The catalytic feature and conditions of the LaFeO3 oxide was identified. The microstructure and phase composition of nitrided layers were analyzed by the optical microscope, transmission electron microscopy, scanning electron microscope and X-ray diffraction, respectively. The microhardness profiles of nitrided layers were measured by micro-hardness tester to evaluate catalytic efficiency of the LaFeO3 oxide. The X-ray photoelectron spectroscopy was applied to reveal the catalytic behavior. The results show that the LaFeO3 perovskite oxide exhibited an excellent catalytic activity via accelerating dissociation of ammonia molecules and diffusion of nitrogen atoms. The dehydrogenation reaction of ammonia molecules was the rate-determining step for the rare earth nitriding, which was greatly affected by gas pressure and ammonia flow rate. The LaFeO3 catalyst shows an excellent durability of catalytic activity in low pressure and low flow rate conditions.

Structural, optical and electrical properties of 0.97(PbTiO3)-0.03(LaFeO3) solid solutions

Abstract Pure and modified lead titanate PbTiO3 (PT) by 3% of the lanthanum iron oxide LaFeO3 (LF) samples were prepared by a sol-gel process. The calcined powders (at 700 °C for 2h) were structurally characterized by X-ray diffraction and Raman spectroscopy, it has been proven that these materials have a single phase as a perovskite-type. Furthermore, DRX and Raman spectrum revealed local lattice distortions from tetragonal structure (P4/mmm) for non-doped sample (PT-LF0%) to pseudo-cubic structure (Pm-3m) for doped sample (PT-LF3%). Optical properties were investigated by UV visible (UV-vis) absorption spectroscopy at room temperature. The UV-vis spectrum indicated that the studied powder has an optical band gap of 2.032 eV making of this material a good candidate for photovoltaic applications. In order to investigate their electrical properties, we have pressed the calcined powder into the pellets and heat treated at 1100 °C for 4h. The compound exhibited a high dielectric constant and a low dielectric loss. Empirical laws of the Curie-Weiss and of the Uchino were performed to extract electrical parameters in wide frequency range.

Low-temperature gas nitriding of AISI 4140 steel accelerated by LaFeO3 perovskite oxide

Rare earth nitriding was considered as an effective method to accelerate the nitriding efficiency. However the catalytic mechanism was not clear due to the uncertainty of rare earth (RE) elements’ existence during nitriding. In the present work, the LaFeO3 perovskite oxide was attempted to use as a catalyst in the gas nitriding for the first time. The effect of nitriding temperature on the microstructure and properties of the RE nitrided layer was investigated and the catalytic mechanism of the RE was discussed. The microstructure, phase composition and microhardness profiles of nitrided layers were characterized by the optical microscope, X-ray diffraction and micro-hardness tester, respectively. The corrosion resistance of nitrided layers was tested by the potentiodynamic polarization technique. Pin-on-disc tribometer were applied to evaluate the wear property. The X-ray photoelectron spectroscopy and scanning electron microscope equipped with an energy dispersive X-ray spectroscopy were used to identify the catalytic mechanism of the RE by analyzing the chemical state and elemental distribution on the nitrided surface. The results show that a perovskite-type oxide, LaFeO3, would form after the gas nitriding, which presents an obvious catalytic activity and increases the thickness of nitrided layers. In addition, the mechanical and corrosion properties could also be improved after nitriding with RE addition. The LaFeO3 perovskite oxide could accelerate the nitriding rate by adjusting the ratio of the adsorbed nitrogen (N) and dissolved N. On the other hand, the sufficient oxygen vacancies in the LaFeO3 oxide could provide more diffusion routes for N atoms.