Perovskite-type Oxide Catalysts Research Articles

Development of Ni-doped A-site lanthanides-based perovskite-type oxide catalysts for CO2 methanation by auto-combustion method.

Engineering the interfacial interaction between the active metal element and support material is a promising strategy for improving the performance of catalysts toward CO2 methanation. Herein, the Ni-doped rare-earth metal-based A-site substituted perovskite-type oxide catalysts (Ni/AMnO3; A = Sm, La, Nd, Ce, Pr) were synthesized by auto-combustion method, thoroughly characterized, and evaluated for CO2 methanation reaction. The XRD analysis confirmed the perovskite structure and the formation of nano-size particles with crystallite sizes ranging from 18 to 47 nm. The Ni/CeMnO3 catalyst exhibited a higher CO2 conversion rate of 6.6 × 10-5 molCO2 gcat -1 s-1 and high selectivity towards CH4 formation due to the surface composition of the active sites and capability to activate CO2 molecules under redox property adopted associative and dissociative mechanisms. The higher activity of the catalyst could be attributed to the strong metal-support interface, available active sites, surface basicity, and higher surface area. XRD analysis of spent catalysts showed enlarged crystallite size, indicating particle aggregation during the reaction; nevertheless, the cerium-containing catalyst displayed the least increase, demonstrating resilience, structural stability, and potential for CO2 methanation reaction.

A-site defective La2-xCuO4 perovskite-type oxides for efficient oxidation of cyclohexylbenzene.

Phenol production through the oxidation of cyclohexylbenzene (CHB) and the subsequent decomposition of tertiary hydroperoxide has attracted more and more attention. In this study, defective La2-xCuO4 perovskite-type oxide catalysts with tunable A-site deficient structures and abundant surface oxygen vacancies were developed for the liquid phase oxidation of CHB to produce cyclohexylbenzene-1-hydroperoxide (CHBHP). By tuning the amount of A-site La ions in the perovskite structure, more surface oxygen vacancies and Cu+ species were formed in catalysts. The A-site-deficient La1.9CuO4 catalyst achieved significant catalytic efficiency along with a high CHBHP yield of 27.6% at 48.6% CHB conversion under reaction conditions (i.e., 120 °C and 12 h), outperforming those of other transition metal-based catalysts previously reported in the literature. A series of structural characterization methods and catalytic reactions highlighted the crucial roles of surface oxygen vacancies and metal La and Cu ions in the oxidation process. It was revealed that metal ions favored CHB adsorption and activation, while surface oxygen vacancies facilitated the creation of active adsorbed oxygen species. The present study offers an opportunity for the future design of new high-efficiency heterogeneous catalyst systems for CHB oxidation to obtain phenol.

Perovskite-Type Oxide Catalysts in CO2 Utilization: A Principal Study of Novel Cu-Doped Perovskites for Methanol Synthesis

Six different perovskite-type oxides were investigated with respect to their ability for methanol synthesis via H2 and CO2: Fe-, Mn-, and Ti-based perovskites were prepared with and without Cu doping. For assessment, the catalysts were subjected to preliminary tests at atmospheric pressure to evaluate their ability to activate CO2. Additional catalytic tests with the doped versions of each catalyst type were carried out in a pressured reactor at 21 bar. After the measurements, the catalysts were characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). All catalysts were able to produce methanol in the pressure tests. CO2 conversions between 14% and 23% were reached at 400 °C, with the highest methanol selectivity at the lower temperature of 250 °C. The combination of XRD and SEM revealed that the Fe-based and Ti-based perovskites were stable under reaction conditions and that catalytically highly active and stable nanoparticles had formed. The minor formation of CaCO3, which is a deactivating phase, was observed for one catalyst. These nanoparticles showed resistance to coking and sintering. However, the yield and selectivity for methanol need to be improved via the further tailoring of the perovskite composition.

Surface modification of LaMnO3 perovskite supported on CeO2 using argon plasma for high-performance reduction of NO

The ever-increasing industrial and motor vehicle activities led to the overwhelming emission of nitrogen oxides (NOx) to the atmosphere, posing a serious environmental challenge. Selective catalytic reactions, based on Perovskite-type metal oxide catalysts, are a proven method used to eliminate NOx compounds and prevent their discharge to the ecosystem. Herein, LaMnO3 nanocatalysts were synthesized by the sol-gel auto-combustion method and supported on CeO2 support using dry impregnation method and used in the simultaneous catalytic reduction process of NO and CO. As a novel idea, the prepared nanocatalysts were treated using argon non-thermal glow discharge plasma to alter the surface properties. The physicochemical properties of these particles were determined using FT-IR, XRD, EDX, FE-SEM, and BET analysis. The plasma treatment process managed to reduce surface impurities. Additionally, the dispersion of the perovskite nanoparticles over the ceria support and the specific surface area was improved, while the diameter of the nanocatalysts was declined. As a result, the plasma modified LaMnO3/CeO2 nanocatalysts improved the conversions of NO and CO by a maximum of 41.19 and 49.11 %, respectively. The produced nanocatalysts were highly stable during the reduction process and lost 3.94 % of their activity after 30 h of operation. The plasma-based surface modification process was utterly effective in boosting the catalytic performance, while it was relatively cheap and easy to carry out.

Metal-organic frameworks-derived perovskite catalysts for efficient degradation of 2, 4-dichlorophenol via peroxymonosulfate activation

Developing highly efficient and stable catalysts toward advanced oxidation technology is the key to achieve industrial peroxymonosulfate (PMS) activation for pollution degradation. Perovskite-type oxide catalysts show high activity and stability for PMS activation, yet the small specific surface area of perovskite catalysts limits the increase of catalytic performance. Metal-organic frameworks (MOFs) have been widely used as the templates/precursors to prepare high specific surface area nanomaterials. In this study, two kinds of high surface area perovskites LaCoO3 and LaMnO3 were firstly fabricated with MOFs as templates. Benefiting from the extraordinary skeleton structure of MOFs, well-defined architecture and porous perovskite catalysts show superior catalytic performance towards PMS activation for the degradation of 2, 4-dichlorophenol (2, 4-DCP), with a 99.8% degradation of 2, 4-DCP in 25 min for LaCoO3 catalyst. Moreover, the LaCoO3 catalysts exhibit long-term stability with a slight loss of catalytic activity during 3 times recycled experiments. This study not only developed high activity catalysts for PMS activation, but also expanded the MOFs applications for environment and energy.

Bifunctional electrocatalysts of lanthanum-based perovskite oxide with Sb-doped SnO2 for oxygen reduction and evolution reactions

Bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are developed with perovskite-type oxide catalyst and antimony-doped tin oxide (ATO) as an oxidation-resistant conductive additive to increase the stability under an oxidizing atmosphere. In conventional carbon-supported catalysts, carbon plays an important role not only in increasing electric conductivity but also in catalyzing the first 2-electron reaction of the ORR. The ATO-mixed catalyst itself requires a perovskite-type oxide (ABO3) catalyst that is active in the first step of the ORR, such as La0.6Ca0.4MnO3 (LCMO), because of the poor ORR activity of ATO. On the other hand, OER performance strongly depends on the composition of the perovskite oxide and La0.6Ca0.4CoO3 (LCCO) shows high OER activity. Here, La0.6Ca0.4Co0.7Mn0.3O3 (LCCMO), in which Co and Mn are mixed at the B site of the perovskite-type oxide, mixed with ATO is proposed as a carbon-free bifunctional catalyst that shows activity for both the ORR and OER. The activity and durability of gas-diffusion air electrodes with the bifunctional catalysts are evaluated in zinc–air batteries, and the results suggest that the catalyst with ATO achieved similar charge-discharge performance and a longer lifetime compared to the conventional catalyst with carbon.

Oxygen reduction/evolution activity of air electrodes using nitrogen-doped and perovskite-type oxide-loaded reduced graphene oxides

Oxygen reduction/evolution bi-functional air electrodes with high activity are required for constructing high-performance metal–air secondary batteries. Conventionally, carbon-supported electrocatalysts have been used as the air electrode materials. However, these types of air electrodes have a problem that the carbon black is corroded to water-soluble organic compounds during oxygen evolution reaction. Therefore, we have investigated reduced graphene oxides as an alternative to the conventional carbon black. Cyclic voltammetry in the range of the potential in which the oxygen evolution reaction occurs revealed that the reduced graphene oxide is stable against corrosion during the oxygen evolution reaction. This result indicates that the reduced graphene oxide is a promising candidate electrode material for bi-functional air electrodes. To improve the oxygen reduction and evolution activities of reduced graphene oxides, doping of nitrogen species and loading of perovskite-type oxide catalysts to reduced graphene oxide were examined. It was found that doping of nitrogen species was effective for improving both the oxygen reduction and evolution activity. LaMnO3 and LaNiO3 catalysts were effective for improving the oxygen reduction and evolution activities, respectively. The best oxygen reduction and evolution activity was obtained by the LaMnO3-loaded nitrogen-doped reduced graphene oxide and LaNiO3-loaded nitrogen-doped reduced graphene oxide, respectively.

PM oxidation over Ag-loaded perovskite-type oxide catalyst prepared by thermal decomposition of heteronuclear cyano-complex precursor

The Ag-loaded perovskite-type oxide catalysts (Ag/LaFeO3-CN and Ag/LaFeO3-imp) were prepared using two different methods, and their catalytic activities for carbon combustion were examined. Ag loading was observed to exhibit a positive effect on the catalytic activity of carbon combustion for an Ag/LaFeO3-CN catalyst that was prepared by the calcination of an Ag-loaded heteronuclear metal cyano-complex precursor. However, Ag loading was not observed to be significantly effective in case of Ag/LaFeO3-imp that was prepared by a general impregnation method. Such a noticeable enhancement in the activity of an Ag/LaFeO3-CN catalyst was assumed to originate from both the high dispersion of Ag that was loaded on LaFeO3 and from the formation of reactive oxygen species between metallic Ag species and the perovskite-type oxide.

Study of Fe, Co, and Mn-based perovskite-type catalysts for the simultaneous control of soot and NOX from diesel engine exhaust

This paper discusses, the nanometric size effects, including intrinsic factors such as structure, the nature of A-site ion substitution, B-site ions, on the redox properties of nanometric La1−xKxFeO3, La1−xKxCoO3, La1−xNaxMnO3, La1−xKxMnO3, perovskite-type oxide catalysts. The external factors of catalyst and soot particulate, the content of NO and O2 and the ratio of catalyst and gas flow rate on the catalytic activity for the simultaneous removal of NOX and soot particulates were systematically investigated. The catalysts were characterized by means of SEM, EDX, XRD and FT-IR and the catalytic potential for the simultaneous removal of nitrogen oxides (NOx) and diesel particulate matter (soot) were evaluated by temperature-programmed oxidation reactions. The entire catalyst samples obtained the perovskite structure, with high activities for the simultaneous elimination of soot and NOX. Alternatively, the number of surface atoms is much higher than the normal bulk catalysts and the size of the nanoparticle is also smaller. These characteristics are beneficial for the adsorption and activation of reactant molecules including NO or O2, or even soot particle.

Synthesis and Performance of Transition Metal Based Perovskite Catalysts for Diesel Soot Oxidation

In present investigation, the effect of the intrinsic factors including the structure, nature of B-site ions in the four systems LaCoO3, LaNiO3, LaFeO3 and LaZnOy perovskite-type oxide catalysts, and the external factors of catalyst-soot contacting model, and the operating parameters such as air flow rate and temperature on the catalytic performances for the combustion of diesel soot were reported. The catalysts were characterized by XRD, FTIR, SEM, and N2-sorption. Activity of the catalyst for soot oxidation was evaluated on the basis of light off temperature characteristics Ti, T50 and T100. LaCoO3, LaFeO3 and LaNiO3 samples possessed the perovskite structure, and gave high activities for the total oxidation of soot below 445 oC. Whereas, LaZnOy catalyst was not indicating the ABO3 perovskite structure and existed as a mixture of metal oxides. The activity order in decreasing sequence of the catalyst was as follows: LaCoO3>LaFeO3>LaNiO3>LaZnOy. SEM pictures of the perovskite samples showed that the particles sizes were close to 100 nm.

ORR and Oer Activity of the Carbon-Free Perovskite-Type Oxide Catalyst for Secondary Zn-Air Battery

ORR and OER Activity of the Carbon-free Perovskite-type Oxide Catalyst for Secondary Zn-air Battery. Tatsuya Takeguchi (*,a), Ryo Kobayashi (a), and Koichi Ui (a) (*) Corresponding author (a) Department of Chemistry and Biological Sciences, Faculty of Science and Engineering, Iwate University, Iwate 020-8551, Japan. Introduction: Rechargeable Zn-air batteries have been expected as the next-generation energy storage devices because of its high theoretical energy density of 1300 Wh/kg1). However, it is desired to reduce overpotentials for ORR and OER on the positive electrode during discharging and charging reactions. Carbon supports on the positive electrode are easily oxidized during the charging reaction. Therefore, high-performance and carbon-free positive-electrode catalysts are indispensable. It is reported that a perovskite-type LaSr3Fe3O10 (LSFO) has a high electrical conductivity and high activities for ORR and OER2). In this study, the carbon-free LSFO pellets were used as positive electrode for Secondary Zn-air batteries, charge and discharge test was conducted. Experimental: In this study, the LSFO pellets (Santoku Co.) were used as the catalysts of the positive electrode. The LSFO powders were pressed at 15 MPa for 10 min and pelletized into disks of 10 mm in diameter for LSFO pellet sample. For porous LSFO pellet, mixtures of LSFO powders and C powder were used. These pellets were calcined in air at 900 oC for 10 h. The OER and ORR activities of the as-prepared pellets were determined by charge (12 h) and discharge (12 h) cycle at 0.5 mA cm-2 between 0.5 and 2.5 V at 25 oC in 4.0 mol dm-3 - KOH 0.3 mol dm-3 ZnO electrolyte using a H-type cell. The LSFO pellet, the porous LSFO pellet, or Pt/C plate was used as the working electrode, while a Zn plate was used as counter electrode, respectively. Results and Discussion: Charge and discharge profiles at 0.5 mA cm-2 for secondary Zn-air battery with carbon-free LSFO positive electrode are shown in Fig. 1. For the LSFO pellet and porous LSFO pellet, overpotentials of OER and ORR are much lower than reference Pt/C because of the easily removable oxygen present in LSFO particles. Although these LSFO pellets are carbon-free, their activities are much higher than those of Pt/C. Activates of LSFO for both ORR and OER are stable, although Pt/C is deactivated owing to the oxidation of carbon during OER. Porous structures Energy efficiency based on discharge voltage/charge voltage is as followed: Porous LSFO pellet > LSFO pellet >> Pt/C (87.1% > 83.8% > 51.7%) Carbon-free LSFO clearly reduces the overpotential of Zn-air battery and enhances the energy efficiency. Porous structure improved the efficiency of both ORR and OER. Perovskite-type oxide catalysts with a high electrical conductivity and high activities should be potential candidates as positive electrode for the next-generation metal-air battery. References 1) Z. Chen, et al., Nano Lett., 12, 1946 (2012). 2) T. Takeguchi, et al., J. Am. Chem. Soc., 135, 11127 (2013). Acknowledgements This research was partially supported by the New Energy and Industrial Technology Development Organization (NEDO), Japan. Figure 1

A Comparative Study of Toluene Oxidation on Different Metal Oxides

This work reports the results of experimental and theoretical investigation of toluene oxidation on different metal oxide based catalysts (manganese oxide, MnOx, mixed manganese-iron oxide, MnFe, perovskite-type manganese oxide, LaMnO3 and commercial Pt-Al2O3 catalyst). Particular attention was devoted to single and mixed manganese based oxides and ceria based materials as alternatives to conventionally used noble metal containing catalysts. Toluene oxidation was performed under steady-state conditions in an integral fixed bed reactor operating over a wider range of reaction temperatures and at various space times. The influence of reaction variables on the rate of toluene oxidation was examined using the simple first-order kinetic model and the one-dimensional (1D) pseudo-homogeneous model to describe the reaction system. The proposed model was verified comparing the theoretical predictions with the experimental laboratory results. The results of catalytic tests indicated that the mixed manganese-iron oxide (MnFe) exhibited remarkable catalytic activity for the toluene oxidation, almost comparable with the activity of the commercial Pt-Al2O3. The reaction temperature T50 corresponding to 50% of the toluene conversion was observed at 419 K for the MnFe oxide and at 405 K for the Pt-Al2O3. A very good agreement of experimental data with the proposed 1D model was obtained. Based on the shape of the light-off curve and the values of the apparent activation energies, which decreased from 120.36 kJ/mol to 16.88 kJ/mol with reaction temperature increase, it was concluded that the reaction rate was probably limited by the mass transfer, no matter the relatively small catalyst particle size fraction employed in this study (315 - 400µm).

Preferential oxidation of CO on a La-Co-Ru perovskite-type oxide catalyst

A Ru-containing perovskite-type oxide La(Co,Ru)O3 of nominal composition LaCo0.8Ru0.2O3 was prepared by ultrasonic spray combustion and tested for the preferential oxidation of CO (PROX). EXAFS indicated that Ru adopted the coordination environment of Co in LaCoO3 while Co was present as LaCoO3 and Co3O4. PROX activity was replaced by CO hydrogenation activity above 250°C. Short oxidation at 500°C between temperature programmed reaction ramps did not restore the initial La(Co,Ru)O3 structure but generated a catalyst with improved PROX activity compared to the initial La(Co,Ru)O3. Under reductive PROX conditions the material experienced structural changes that improved its overall catalytic activity only if the catalyst was oxidized after each temperature programmed ramp.

Catalytic activities of supported perovskite promoter catalysts La2NiMnO6–CuCl2/γ-Al2O3 and La1.7K0.3NiMnO6–CuCl2/γ-Al2O3 for ethane oxychlorination

Supported perovskite promoted catalysts La2NiMnO6–CuCl2/γ-Al2O3 and La1.7K0.3NiMnO6–CuCl2/γ-Al2O3 were prepared by mechanical mixing method, and characterized by XRD, H2-TPR, XRF, XPS and magnetization techniques. The catalyst doped with potassium La1.7K0.3NiMnO6–CuCl2/γ-Al2O3 possesses a large amount of Mn4+ and surface-adsorbed oxygen species, which accelerate the oxidation of Cu+ by a circular reaction and increase the release of Cl2, and therefore promote the conversion of C2H6 and the selectivity to C2H3Cl. The catalyst La1.7K0.3NiMnO6–CuCl2/γ-Al2O3 shows better catalytic activity for ethane oxychlorination with the C2H6 conversion of 100% and the C2H3Cl selectivity to 59.4%. The total selectivity to C2H4 and C2H3Cl maintains over 81% in 95h. This study points out a potential way to develop more active perovskite-type oxide catalysts for ethane oxychlorination.

The effect of promoters in La0.9M0.1Ni0.5Fe0.5O3 (M = Sr, Ca) perovskite catalysts on dry reforming of methane

Nickel-based catalysts are typically used for syngas production via reforming reactions. The reforming of methane using carbon dioxide, called dry reforming of methane (DRM), is an effective way to produce syngas from these two notable greenhouse gases. However, Ni-based catalysts used for DRM undergo severe coke deposition. In the current study, perovskite-type oxide catalysts were prepared using the modified EDTA-cellulose method and characterized by the N2 physisorption, TPR, CO2-TPD, XRD, TGA, SEM and TEM-EDX techniques. The influence of partial substitution of La by Sr/Ca was investigated in the dry reforming reaction for the production of synthesis gas, and the basicity of the catalysts was varied by substituting the A site with either Sr or Ca, which modified the catalytic activity under the tested conditions. It was found that the perovskite catalysts demonstrated superior carbon resistance during the reaction, with La0.9Ca0.1Ni0.5Fe0.5O3 catalyst exhibiting the best catalytic performance among the prepared perovskite catalysts.

Cyanosilylation of benzaldehyde with TMSCN over perovskite-type oxide catalyst prepared by thermal decomposition of heteronuclear cyano complex precursors

The perovskite-type oxide catalyst, SmFeO3, prepared by decomposition method of heteronuclear cyano complex precursor (CN method) was applied to liquid-phase organic reaction, cyanosilylation of benzaldehyde with TMSCN. The maximum catalytic activity per catalyst weight was achieved at 800 °C of calcination temperature in CN method and it was found that the catalytic activity was strongly related to the crystallinity of SmFeO3 catalyst. The catalytic reaction performed in the presence of pyridine and 2,6-di-tert-butylpyridine suggests that the catalytically active sites are the Bronsted acid sites formed on the SmFeO3 catalyst. The catalytic activity of SmFeO3 catalyst prepared by CN method was much higher than those of acid catalysts: SiO2–Al2O3 and Amberlyst.

Pd-supporting LaCoO3 catalyst with structured configuration for water gas shift reaction

The purpose of this study was to develop a structured perovskite-type oxide catalyst for the water gas shift (WGS) reaction, which could make lattice oxygen mobile at a low external heat energy by preparing it as a thin catalyst layer on a metal plate. The thickness of the formed LaCoO3 layer was about 20μm, which was confirmed by FE-SEM and EDX analysis. For enhancing its WGS reaction performance, a palladium (Pd) component was supported on the structured catalyst using various Pd precursors. When using a PdCl2 aqueous solution which was prepared by filtration of the PdCl2 slurry (the filtration liquid), the Pd-supporting LaCoO3 structured catalyst showed a high and stable activity. The reason for such an enhanced activity was that the supported Pd was in a highly dispersed state, which was derived from the electrostatic interaction between [PdCl3(H2O)]− as the anionic charged precursor in the filtration liquid and the oppositely charged LaCoO3 support surface confirmed by a UV–vis measurement. In order to remove the remaining chloride ligand from the Pd-supporting LaCoO3 catalyst surface, a washing treatment was performed by immersing the as-made catalyst in water, NH3 (aq) or NaOH (aq) at pH 11.5 for 30min. Consequently, these washing processes were effective for eliminating the remaining chloride ion from the catalyst surface and improving the shift activity of the catalyst. The catalyst washed using NH3 (aq) showed the highest activity among these catalysts.

Modifying perovskite-type oxide catalyst LaNiO3 with Ce for carbon dioxide reforming of methane

Perovskite-type oxide catalysts LaNiO3 and La1−xCexNiO3 (x ≤ 0.5) were prepared by the Pechini method and used as catalysts for carbon dioxide reforming of methane to form synthesis gas (H2 + CO). The gaseous reactants consisted of CO2 and CH4 in a molar ratio of 1:1. At a GHSV of 10,000 hr−1, CH4 conversion over LaNiO3 catalyst increased from 66% at 600 °C to 94% at 800 °C, while CO2 conversion increased from 51% to 92%. The achieved selectivities of CO and H2 were 33% and 57%, respectively, at 600 °C. To prevent the deposition of carbon and the sintering nickel species, some of the Ni in perovskite-type oxide catalyst was substituted by Ce. Ce provided lattice oxygen vacancies, which activated C–H bonds, and increased the selectivity of H2 to 61% at 600 °C. XRD analysis indicates that the catalyst exhibited a typical perovskite spinel structure and formed La2O2CO3 phases after CO2 reforming. The FE-SEM results reveal carbon whisker of the LaNiO3 catalyst and the BET analysis indicates that the specific surface area increases after the reforming reaction. The H2-TPR results confirm that Ce metals can store and provide oxygen.

Synthesis of LaxK1–xCoO3 nanorod and their catalytic performances for CO oxidation

A series of LaxK1–xCoO3 nanorod oxides with perovskite structure were synthesized by sol-gel method using polyvinyl alcohol (PVA) as additive. These perovskite-type complex oxide catalysts were characterized by the techniques of X-ray diffraction (XRD), infrared (IR), Brumauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). And the results showed that nanorods of La1–xKxCoO3 perovskite-type complex oxides were fabricated by sol-gel method when the mass concentration of PVA was 4% and the calcined temperature kept at 700 °C for 4 h. The catalytic results of CO oxidation showed that the LaxK1–xCoO3 catalysts had high activity. LaCoO3 nanorods exposed more {110} plane than LaCoO3 nanoparticles, which was beneficial to the catalytic oxidation of CO. LaCoO3 nanorods had the best catalytic performance for the oxidation of CO. At 200 °C, the CO conversion could reach 100%.

The Structures and Preparation Methods of Perovskite-Type Oxide Catalysts for Natural Gas Catalytic Combustion

Catalytic combustion technology can effectively reduce the temperature of the combustion reaction and significantly inhibit the formation of NOx. Perovskites catalyst materials have high stability, varied chemical composition, and low cost etc. A combination of catalytic combustion technology and perovskite catalyst materials has great significance for energy industry and environment protection. However, improving lower temperature catalytic activity and high temperature thermostability performance of perovskite catalyst is still major problem. Some researchers have improved the activity and stability of perovskite catalysts for methane combustion by different preparation methods. The structure and preparation methods of perovskite-type oxide catalysts are presented.