Enhanced photocatalytic performance of NiFe2O4 nanoparticle spinel for hydrogen production

The spinel NiFe₂O₄, prepared from nitrates precursors, was characterized by thermal analyses, X-Ray Diffraction, UV-Vis diffuse reflectance, Scanning electron microscopy, X-Ray Fluorescence spectrometry, X-ray photoelectron spectroscopy and photo-electrochemistry measurements. The X-ray diffrcation analysis of the powder indicates a cubic phase with a lattice constant of 8.327(8) Å and crystallite size of 19 nm. The X-Ray Fluorescence spectrometry indicates a stoichiometry, very close to NiFe₂O₄ catalyst calcined at 900 °C The X-ray photoelectron spectroscopy analysis confirmed the valences and crystallographic sites of the transition elements. The direct optical gap of NiFe₂O₄ (1.78 eV), due to the crystal field splitting of the 3d orbital in the octahedral site, is well suited for the solar spectrum and attractive for photo-electrochemical H₂ production. The flat band potential (E_fb = 0.47 V_SCE) was obtained from the capacitance-potential (C^?2 - E) characteristic in NaOH (0.1 M) electrolyte. A conduction band of ?1.11 V_SCE, more cathodic than the H₂ level (?0.8 V_SCE), enabled the use of NiFe₂O₄ for the water reduction into hydrogen. The H₂ evolution rate of 46.5 μmol g^?1 min^?1 was obtained under optimal conditions (1 mg of catalyst/mL, NaOH and 50 °C) in the presence of SO₃^2? (10^?3 M) as hole scavenger under visible light flux of 23 mW cm^?2. A deactivation effect of only 1% was obtained.     

Elaboration,physical and photo-electrochemical properties of NiCr2O4. Application to hydrogen production under visible irradiation

The physical and photoelectrochemical characterization of NiCr₂O₄, prepared by sol gel route, were investigated to be applied for the H₂ production. The thermal gravimetry (TG) indicates that the single phase is formed above 530 °C as confirmed by X-ray diffraction (XRD). The Nano powder crystallizes in a tetragonal structure with lattice constants: a = 8.3276 Å and c = 8.5542 Å and a particle size of 63 nm, smaller than that obtained by Transmission Electronic Microscopy (TEM) analysis; the latter gives sizes between 80 and 150 nm, indicating crystallites agglomeration. The variation of the dielectric constant (ε) with temperature gives a relative value of 26 at 10 kHz. A direct optical transition at 1.79 eV is determined from the diffuse reflectance spectroscopy assigned to Cr³⁺ octahedrally coordinated. The thermal variation of the conductivity shows that 3d-electrons are localized and the data are modelled by a lattice-polaron hopping with an activation energy of 0.17 eV. The dependence of the interfacial capacitance on the potential (C⁻² - E) indicates p-type behavior with a flat band potential (E_fb) of −0.23 VSCE and holes density (N_A) of 5.88 × 10¹⁶ cm⁻³. The potential of the conduction band (−1.85 V_SCE) is below the H₂O/H₂ level (∼-1.2 V_SCE), allowing a spontaneous H₂-release under visible light. The O₂ evolution occurs at high over-voltage as shown from the intensity-potential (J-E) characteristic in Na₂SO₄ solution (0.1 M) and a hole scavenger was used to preclude the photo corrosion. The NiCr₂O₄ mass, pH and the hole scavenger (S₂O₃²⁻ and NO₂⁻) were optimized. The H₂ volume reached 65 μmol with an evolution rate of 8.6 μmol g⁻¹ min⁻¹, liberated under optimized conditions {1.2 g catalyst L⁻¹, pH ∼9 with thiosulfate S₂O₃²⁻ [10⁻³ M]}.     

Hydrogen evolution under visible light illumination on the solid solution CdxZn1-xS prepared by ultrasound-assisted route

The complete solid solution Cd_xZn_1-xS (0 ≤ x ≤ 1) prepared by ultrasound-assisted route is used for the H₂ formation upon visible light illumination. The correlation of chemical and physical characterizations permits to assess the feasibility of the system for the photocatalytic hydrogen evolution. The compounds crystallize in a cubic structure (x < 0.5) and convert to hexagonal variety above 0.5 with a crystallite size (8–17 nm). All materials exhibit n-type conduction with an activation energy (0.22–0.05 eV). The optical transitions are directly allowed (3.10–2.30 eV) and appropriately matched to the sun spectrum while the conduction band, deriving from (Zn, Cd) ns orbital (∼-1 V_SCE), is positioned above the H₂O/H₂ potential (∼-0.68 V_SCE), allowing H₂-liberation under visible illumination. The photocatalyst dose, pH and SO₃²⁻ concentration are optimized. Under the favorable conditions, the H₂ liberation rate reaches 12 × 10⁻⁴ mL mg⁻¹ min⁻¹ with a quantum yield η(H₂) of 1.40%.     

Preparation and characterization of α-Fe2O3 supported clay as a novel photocatalyst for hydrogen evolution

Improvement in the hydrogen evolution is reported over α-Fe₂O₃ supported on Algerian natural clay. The hetero-system is prepared by impregnation and calcination at 450 °C. It was characterized by X-ray diffraction, SEM analysis, FTIR spectroscopy and photo electrochemistry. The hematite Fe₂O₃ crystallizes in the corundum structure and exhibits n-type conductivity with a flat band potential of −0.88 V_SCE. Hence, the photo electrons located in Fe₂O₃-CB (−1 V_SCE) have high ability to reduce water into hydrogen. α-Fe₂O₃ gets effectively dispersed in the clay and the photoactivity increases with increasing its content. SO₃²⁻, working as hole scavenger, provides an absolute protection against the photo corrosion and favors the charges separation. The best performance of H₂ evolution occurs at alkaline pH on 10% Fe₂O₃/clay with a liberation rate 0.121 μmol/mg/min and a quantum efficiency of 1.2%.     

Elaboration and characterization of the brownmillerite Ca2Fe2O5 synthesized by citrate sol-gel method. Application for photocatalytic H2-Production under visible light over Ca2Fe2O5/ZnO hetero-system

The present work is devoted to the synthesis of the ferrite Ca₂Fe₂O₅ as photocatalyst crystallizing in the brownmillerite structure. The ternary oxide is prepared by sol-gel auto combustion and characterized by physical and electrochemical methods. The thermal analysis (TG/DSC) shows that, the formation of the brownmillerite is observed above 660 °C. The X-ray diffraction and BET analysis show respectively a single phase with an active surface area of ～6 m² g^?1. The SEM micrographs exhibit an inhomogeneous structure formed by agglomeration of irregular shaped grains, confirmed by the laser granulometry analysis. The forbidden band (～2.3 eV) determined from the diffuse reflectance, permits to explore ～ 30% of the sun spectrum into chemical energy. The p-type comportment of Ca₂Fe₂O₅ is demonstrated by the capacitance-potential (C^?2 - E) graph with a flat band potential (E_fb = 0.93 V_SCE), due to oxygen over-stoichiometry. The negative potential of the conduction band (?1.06 V_SCE) predicts the feasibility of the H₂ generation. Indeed, Ca₂Fe₂O₅ is chemical stable in a wide pH domain and is positively experimented as photocatalyst for the H₂-production under visible light. The best performance is obtained in alkaline medium (NaOH, 0.1 M) with a mean evolution rate of 18 μmol g^?1 min^?1. However, Ca₂Fe₂O₅ coupled to ZnO sol-gel (ZnO-SG) improves the catalytic performance. The H₂ evolution rate over (Ca₂Fe₂O₅/ZnO-SG) reached 24 μmol g^?1 min^?1 after 60 min. It has also been shown that ZnO–P, prepared by precipitation, is more efficient than that synthetized by sol-gel method (ZnO-SG) and TiO₂–P25.     

Physical and photo-electrochemical characterizations of α-Fe2O3. Application for hydrogen production

The optical, electrical and photo-electrochemical properties of dense hematite α-Fe₂O₃ have been studied for the photo-catalytic hydrogen production. The band gap was evaluated at 1.96 eV from the diffuse reflectance spectrum and the transition is directly allowed; further indirect transition occurs at 2.04 eV. The oxygen deficiency permits the altering of the transport properties and the oxide exhibits n type behavior with activation energy of 0.11 eV. α-Fe₂O₃ is found to be photo-electrochemically active. The flat band potential V_fb (−0.51 V_SCE) and the density N_D (19.12 × 10¹⁹ cm⁻³) were obtained respectively by extrapolating the linear part to C⁻² = 0 and the slope of the Mott–Schottky plot. The complex impedance pattern is circular in the high frequency region followed by a straight line in the low frequency one, a behavior attributed to the Warburg ionic diffusion. The conduction band edge (−0.62 V_SCE) lies below the H₂O/H₂ level (−0.50 V_SCE) and Fe₂O₃ offers the possibility to be used as hydrogen photocathode. The best activity was obtained in SO₃²⁻ (0.5 M, pH 13.8) solution with a rate evolution of 6 ml (g catalyst)⁻¹ min⁻¹.     

Photoelectrochemical properties of doped polyaniline: Application to hydrogen photoproduction

The semi conducting properties of doped polyaniline (emeraldine-salt, PANI) elaborated by chemical route are investigated by the photo-electrochemical technique. The band gap is found to be 1.48 eV and the transition is directly allowed. The electrical conduction obeys to an exponential law with activation energy of 0.13 eV. p-type conductivity is evidenced from the cathodic photocurrent. The energy band diagram clearly shows the spontaneous hydrogen photo evolution. The potential of the conduction band of PANI (−0.93 V_SCE) determined from the capacitance measurements is suitably positioned with respect to H₂O/H₂ level (−0.66 V_SCE). Therefore, the photocatalytic properties of this material has been evaluated according to the hydrogen generation. The best performance is achieved at pH ∼7 with a liberation rate of 0.113 mL h⁻¹ (mg catalyst)⁻¹ and a quantum efficiency of 0.18% under visible light (29 mW cm⁻²). An increase of 56% is obtained on the hetero-system PANI/TiO₂.     

Photocatalytic hydrogen production on the hetero-junction CuO/ZnO

The co-precipitation is successfully used for the synthesis of the hetero-junction CuO/ZnO. Thermal analysis, ATR spectroscopy and diffuse reflectance were used to assess the photoactivity of the hetero-system for the hydrogen formation upon visible light. As expected, the X-ray diffraction shows mixed phases of CuO (tenorite) and ZnO (Wurtzite). The specific surface area is around ~7 m² g⁻¹ with a crystallite size lying between 20 and 49 nm. The diffuse reflectance indicates an indirect transition at 3.13 eV for ZnO and a direct transition at 1.60 eV for the sensitizer CuO. The capacitance-potential (C⁻² - E) characteristic of CuO plotted in Na₂SO₄ electrolyte exhibits p-type comportment with a flat band potential of −0.315 V_RHE and a holes concentration of 8.7 × 10¹⁸cm⁻³. The Electrochemical Impedance Spectroscopy exhibits a semicircle characteristic of the bulk material with an impedance of 1725 Ω cm² which decreases down to 453 Ω cm² under irradiation, supporting the semiconducting character of CuO. ZnO mediates the electrons transport thanks to its conduction band, formed from Zn²⁺: 4s orbital (−0.92 V_RHE); it is positioned cathodically with respect to the H₂O/H₂ level (~-0.74 V_RHE), producing a H₂ evolution under visible light illumination. The performance peaks at pH ~7 on 5% CuO/ZnO for a catalyst dose of 0.25 mg of catalyst/mL of solution in the presence of SO₃²⁻ as holes scavenger. A liberation rate of 340 μmol h⁻¹ (g of catalyst)⁻¹ is obtained with a quantum efficiency of 0.38% under a photons flux of 2.09 × 10¹⁹ s⁻¹.     

Hydrogen production on the new hetero-system Pr2NiO4/SnO2 under visible light irradiation

The Pr₂NiO₄/SnO₂ heterojunction with a mass ratio equal to unity was tested with success for the hydrogen production under visible light irradiation. Pr₂NiO₄, prepared by nitrate route, crystallizes in a tetragonal symmetry with K₂NiF₄ type structure. The physical, electrical and photo-electrochemical characterizations are correlated to show the feasibility of Pr₂NiO₄ for the hydrogen formation under visible light. The enhanced hydrogen production activity is due to electron injection of activated conduction band Pr₂NiO₄-CB (−1.53 V_SCE) into SnO₂-CB (−0.87 V_SCE) which acts as an electron pump, resulting in better water reduction. The band gap of the semiconductor Pr₂NiO₄ is 1.81 eV with a direct optical transition. Pr₂NiO₄ acquired p type conductivity, due to oxygen insertion in the layered lattice with an activation energy of 0.09 eV. The flat band potential (E_fb, 0.18 V_SCE), very close to the photocurrent onset potential (0.13 V_SCE) and the density of the holes (N_A, 1.85 10²⁰ cm⁻³) were obtained from the Mott-Schottky characteristic. H₂ production rate of 24.3 μmol g⁻¹ min⁻¹ is obtained with a quantum yield of 1.45% within 30 min under optimal conditions (1 mg of catalyst/mL, pH ~12 and 50 °C) in presence of S₂O₂⁻³ as hole scavenger under visible light flux of 29 mW cm⁻².     

Ultrathin Ti-doped hematite photoanode by pyrolysis of ferrocene

Ultrathin Ti-doped α-Fe₂O₃ photoanode was prepared by a facile atmospheric pressure chemical vapor deposition method through pyrolysis of ferrocene at 450 °C on Ti foil. The as prepared ultrathin hematite thin film has a surface feature size of 70 × 30 nm and a thickness of 50 nm. The photocurrent of this ultrathin hematite photoanode prepared at 450 °C in 1 M NaOH reaches 900 μA/cm² at 0.6 V_SCE under AM 1.5G illumination. The superior performance to the thin films prepared on FTO glass was ascribed to the diffusion and doping of Ti⁴⁺ from the metal substrate during pyrolysis deposition of hematite on Ti substrate.     

Effect of Ce on the structural features and catalytic properties of La(0.9−x)CexFeO3 perovskite-like catalysts for the high temperature water-gas shift reaction

La_(0.9−x)Ce_xFeO₃ perovskite-like catalysts were investigated for the production of hydrogen from simulated coal-derived syngas via the water-gas shift reaction in the temperature range 450-600 °C and at 1 atm. These catalysts exhibited higher activity at high temperatures (T ≥ 550 °C), compared to that of a commercial high temperature iron-chromium catalyst at 450 °C. Addition of a low Ce content (x = 0.2), has little influence on the formation of the LaFeO₃ perovskite structure, but enhances catalytic activity especially at high temperatures with 19.17% CO conversion at 550 °C and 40.37% CO conversion at 600 °C. The LaFeO₃ perovskite structure and CeO₂ redox properties play an important role in enhancing the water-gas shift activity. Addition of a high Ce content (x = 0.6) inhibits the formation of the LaFeO₃ perovskite structure and decreases catalyst activity.     

Photocatalytic hydrogen generation through water splitting on nano-crystalline LaFeO3 perovskite

Visible light active ABO₃ type photocatalyst with LaFeO₃ composition was synthesized by sol-gel method. The photocatalyst was characterized by different techniques such as X-ray diffraction, BET surface area analysis, particle size analysis, scanning electron microscopy, UV–visible diffuse reflectance spectroscopy (UV–Visible DRS), and photoluminescence spectroscopy. LaFeO₃ photocatalyst exhibited an optical band gap of 2.07 eV with the absorption spectrum predominantly in visible region of the spectrum. The BET surface area of photocatalyst LaFeO₃ was observed as 9.5 m²/g, with the crystallite size of 38.8 nm as calculated by the Debye-Scherer equation. The photocatalytic activity of LaFeO₃ was investigated for hydrogen generation through sacrificial donor assisted photocatalytic water splitting reaction by varying conditions in feasible parametric changes using visible light source, ethanol as a sacrificial donor and Pt solution of H₂PtCl₆ as a co-catalyst. The rate of photocatalytic hydrogen evolution was observed to be 3315 μmol g⁻¹ h⁻¹ under optimized conditions and using 1 mg dose of photocatalyst with reaction time of 4 h and illumination of 400 W.     

Fabrication of nanocrystalline LaFeO3: An efficient sol–gel auto-combustion assisted visible light responsive photocatalyst for water decomposition

Synthesis of nano photocatalysts, LaFeO₃ with orthorhombic perovskite structure by sol–gel auto-combustion method was demonstrated. The samples were characterized by PXRD, SEM, HRTEM, XPS and optical absorption studies. Photocatalytic water decomposition over LaFeO₃ nanoparticles activated at various temperatures without any co-catalyst were investigated under visible light irradiation (λ >> 420 nm). Highest amount of H₂ and O₂ evolved in 180 min over the LaFeO₃ activated at 500 °C was recorded to be 1290 μmol and 640 μmol, respectively having apparent quantum efficiency (AQE) 8.07%. The pronounced activity of nano LaFeO₃ samples towards water decomposition was consistent with BET-surface area and particle size analyses.     

In-situ exsolved NiFe alloy nanoparticles on Pr0.8Sr1.2(NiFe)O4-δ for direct hydrocarbon fuel solid oxide fuel cells

NiFe alloy (NFA) nanoparticles decorated Ruddlesden-Popper (RP) type layered perovskite structure Pr_0.8Sr_1.2(NiFe)O_4-δ (RP-PSNF) have been fabricated by in-situ reduction of cubic perovskite Pr_0.32Sr_0.48Ni_0.2Fe_0.8O_3-δ (P–PSNF) in H₂ at 800 °C. When used as the solid oxide fuel cell (SOFC) anode material, the RP-PSNF-NFA based ceramic anode demonstrates a comparable catalytic activity to Ni-based anode. The SOFC single cell with RP-PSNF-NFA-Gd_0.2Ce_0.8O_2−δ (GDC) anode exhibits a maximum power density of 983 and 770 mW cm⁻² in humidified H₂ and C₃H₈ at 800 °C, respectively. More importantly, the single cell shows a high durability at the current density of 250 mA cm⁻² in humidified C₃H₈ at 800 °C, demonstrating an excellent coking resistance. Overall, this work suggests that RP-PSNF-NFA is a promising anode for direct hydrocarbon fuel SOFCs.     

Proton conductivity in stoichiometric and sub-stoichiometric yittrium doped SrCeO3 ceramic electrolytes

The crystal structure and electrical properties of stoichiometric perovskite proton conductors SrCe_1−xY_xO_3−δ (where x = 0.025, 0.05, 0.075, 0.1, 0.15, and 0.2 and δ = x/2) and substoichiometric Sr_0.995Ce_0.95Y_0.05O_3−δ have been investigated. The conductivities of the samples were measured as a function of the partial pressure of oxygen at 600 and 800 °C, and at two water vapor pressures (P_H2O=0.01 and 0.001 atm). A P_O2 range of 1 atm (pure O₂) to approximately 1 × 10⁻²⁵ atm (N₂/H₂ mix) allowed for the separation of n-(electron), p-(hole), and i-(ionic) type conductivities.In the case of stoichiometric perovskite proton conductors, the unit cell volume (UCV) and calculated density decrease with increasing yttrium content. The ionic and p-type components of the conductivity show threshold effect with Y-doping, which may be related to the double substitution of Y on both A- and B-sites. A maximum ionic conductivity of 5 mS/cm is found at 10% Y, whereas p-type conductivity increases with increasing yttrium concentration. A conductivity component appearing at low oxygen partial pressures decreases with yttrium doping. The substoichiometric material showed a drop in unit cell volume of approximately 0.34 Å³ compared to its stoichiometric partner. The conductivity components of substoichiometric material are higher than the conductivities of corresponding stoichiometric material, being approximately 7 mS/cm for both P_H2O levels.     

Visible light induced hydrogen evolution on new hetero-system ZnFe2O4/SrTiO3

The physical properties and photoelectrochemical characterization of the spinel ZnFe₂O₄, elaborated by chemical route, have been investigated for the hydrogen production under visible light. The forbidden band is found to be 1.92 eV and the transition is indirectly allowed. The electrical conduction occurs by small polaron hopping with activation energy of 0.20 eV. p-type conductivity is evidenced from positive thermopower and cathodic photocurrent. The flat band potential (0.18 V_SCE) determined from the capacitance measurements is suitably positioned with respect to H₂O/H₂ level (−0.85 V_SCE). Hence, ZnFe₂O₄ is found to be an efficient photocatalyst for hydrogen generation under visible light. The photoactivity increases significantly when the spinel is combined with a wide band gap semiconductor. The best performance with a hydrogen rate evolution of 9.2 cm³ h⁻¹ (mg catalyst)⁻¹ occurs over the new hetero-system ZnFe₂O₄/SrTiO₃ in Na₂S₂O₃ (0.025 M) solution.     

Water-splitting mechanism analysis of Sr/Ca doped LaFeO3 towards commercial efficiency of solar thermochemical H2 production

Solar thermochemical (STC) technology utilizes the entire spectrum of solar energy to decompose water to produce hydrogen. This technology reduces carbonic fuels, nearly only producing hydrogen rather than hydrogen-oxygen mixture. However, low water-splitting activity of redox materials restricts improvement of water-hydrogen conversion ratio and fuel production efficiency. Recently, a kind of perovskite LaFeO₃ attracts attention, because of the good performance in photocatalysis hydrogen production. Nevertheless, how LaFeO₃ system works in STC water-splitting cycle is rarely studied. In this paper, the first principle method at density functional theory level is adopted to reveal the hydrogen production mechanism of perovskite LaFeO₃ doped with 25% Sr/Ca at A site. Hydrogen migration on material surface determines hydrogen generation rate. The activation energy of 25%-Ca-doped LaFeO₃ is relatively lower 150.09 kJ/mol. In addition, fuel production efficiency has been calculated. When water to hydrogen conversion ratio is 100%, solar-to-fuel efficiency can reach maximum 0.472. The effect of water-splitting kinetics on hydrogen production is also discussed. The results indicate that when T_red = T_oxi = T = 1200K and water to hydrogen conversion ratio is 10%, the dynamic efficiency of La_0.75Ca_0.25FeO₃ can reach 20%. This research can provide index for improving the hydrogen production performance of STC technology.     

Unusual adsorption behavior of hydrogen molecules on Zr–doped perfect and oxygen–vacancy defective rutile TiO2(110) surfaces: Periodic DFT study

Adsorptions of Zr atom onto the perfect rutile TiO₂(110) and the oxygen vacancy rutile TiO₂ (110) ([TiO₂+V_o]) to form Zr–TiO₂ and Zr‒[TiO₂+V_o] were studied using periodic density functional theory (DFT) method. Three configurations of both Zr–TiO₂ and Zr‒[TiO₂+V_o] surfaces were found and binding energies of Zr atom of the most stable Configurations of Zr–TiO₂ and Zr‒[TiO₂+V_o] surfaces are respectively −3.36 and −3.26 eV. The most stable Configurations of the Zr–TiO₂ and Zr‒[TiO₂+V_o] surfaces were selected in hydrogen adsorption study. Adsorption energies of single H₂ molecule on the most stable Zr–TiO₂ and Zr‒[TiO₂+V_o] are −1.43 and −1.45 eV, respectively. Based on the second H₂ molecular adsorption on the hydrogen pre‒adsorbed Zr–TiO₂ and Zr‒[TiO₂+V_o] surfaces, adsorption energies of −1.90 and −2.55 eV were found, respectively. The second H₂ molecule adsorption was found to be much stronger than the first H₂ molecule adsorbed onto the Zr–TiO₂ and Zr‒[TiO₂+V_o] surfaces by 32.9% and 75.9%, respectively. Either the Zr–TiO₂ or Zr‒[TiO₂+V_o] surface is suggested as hydrogen–storage material and the Zr–TiO₂ can be proposed as an electrical resistance‒based hydrogen sensor.     

Three-dimensionally ordered macroporous LaFeO3 perovskites for chemical-looping steam reforming of methane

Three-dimensionally ordered macroporous (3DOM) LaFeO₃ and nano-LaFeO₃ perovskite-type oxides were synthesized by impregnation of polystyrene (PS) templates and combustion method, respectively. The obtained LaFeO₃ perovskites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, and hydrogen-temperature programmed reduction (H₂-TPR). The performance of the perovskites as oxygen carriers in chemical looping steam methane reforming (CL-SMR) to produce syngas (H₂ + CO) and hydrogen were investigated. The synthesized 3DOM-LaFeO₃ was pure crystalline perovskite giving a surface area of 8.088 m²/g, higher than that of nano-LaFeO₃ particles (4.323 m²/g). In the methane reduction stage, methane was partially oxidized into syngas at a H₂/CO molar ratio close to 2:1 by the 3DOM-LaFeO₃ in the main stage of the reactions. In the steam oxidation stage, the reduced perovskites were oxidized by steam to generate hydrogen simultaneously. No significant decrease of the yields of syngas and hydrogen was observed during ten successive redox cycles, indicating that the 3DOM-LaFeO₃ perovskites have good repeatability. In comparison to nano-LaFeO₃, 3DOM-LaFeO₃ has more stable reactivity of methane oxidation and better resistance to carbon formation. In spite of a part of 3DOM structure were collapsed in the course of the cyclic reactions, the specific surface area of the 3DOM-LaFeO₃ was still higher than that of the nano one. The better reactivity of 3DOM-LaFeO₃ compared with that of nano-LaFeO₃ is partially attributed to the higher surface area.