Hydrothermal stability of MOx-Ce0.75Zr0.25O2 catalysts for NOx reduction by ammonia

Various acidic components（MOx：phosphate,sulfate,tungstate and niobate） were loaded on Ce0.75 Zr0.25 O2 powders by an impregnation method.The as-prepared catalysts were hydrothermally treated at 760 oC for 48 h in air containing 10 vol.% H2 O to obtain the aged catalysts.The catalysts were characterized by X-ray diffraction,Fourier transform infrared spectroscopy,H2 programmed-reduction,NH3 adsorption and deNOx activity measurements.The results showed that,among the catalysts investigated,the phosphated Ce0.75 Zr0.25 O2 catalyst showed the highest hydrothermal stability.The remained high acidity of the phosphated catalyst with moderate redox property helped to maintain the excellent NH3-SCR activity of hydrothermally aged catalyst.Cerium tungstate led to the poor redox property of the tungstated catalyst although the acidity of catalyst was still high.The decomposition of sulfates at temperatures higher than 600 °C restrained the usage of sulfated catalysts in high temperature conditions.The overall dehydration of niobate to niobium oxides led to the low acidity of hydrothermally aged Nb2 O5-Ce0.75 Zr0.25 O2 catalyst.     

Possible negative influences of increasing content of cerium on activity and hydrothermal stability of Rh/ceria-zirconia three-way catalysts

The activity and hydrothermal stability of the Rh/Ce_xZr_(1-x)O_2(x=0,0.05,0.3,0.5) model three-way catalysts for gasoline vehicle emissions control were investigated in this work.Among the Rh/Ce_xZr_(1-)_xO_2 samples with different Ce/Zr ratios,the Rh/ZrO_2 sample exhibits a significantly better activity and hydrothermal stability than the rest of the samples.The impacts of having more Ce components in the Rh/Ce_xZr_(1-x)O_2 catalysts are associated with the strong Rh-O-Ce interaction that tends to over stabilize the rhodium species.A significant amount of such rhodium atoms can be found in the bulk of the support oxides after a hydrothermal aging at 1050℃ with 10% H_2 O in air for 12 h.Differently,the sintering of rhodium on the surface of Rh/ZrO_2 catalysts is the main reason for the catalyst deactivation during the hydrothermal aging.These findings provide an example where high dispersion of supported metal induced by strong metal-support interactions does not necessarily lead to high catalytic activity.     

Catalysis of Ce_xZr_(1–x)O_2 for di-iso-propyl-ether hydration

The catalytic potential of CexZr1–xO2 in isopropyl ether(DIPE) hydration was explored. While the acidic H-zeolite catalyst was favorable for propylene formation through carbenium ion mechanism, Ce-ZSM-5 and CexZr1–xO2 catalysts improved product selectivity of isopropyl alcohol(IPA) through redox mechanism. The catalytic property of CexZr1–xO2 depended on the preparation method and variable, type of cerium precursor and Ce/Zr ratio. By means of characterizations with X-ray diffraction, N2 adsorption isotherms and NH3 temperature programmed desorption, tetragonal phase of CexZr1–xO2 was proposed as the active phase in which CeO2 and ZrO2 catalyzed synergistically the DIPE hydration with IPA product selectivity. The CexZr1–xO2 prepared from cerium sulfate precursor with co-precipitation hydrothermal method exhibited maximum catalytic activity and IPA product selectivity. The precursor effect was attributed to the stabilization of SO42– species on the tetragonal phase of CexZr1–xO2 and super solid acidity.     

Rare earth metal modified three dimensionally ordered macroporous MnOx-CeO2 catalyst for diesel soot combustion

Three dimensionally ordered macroporous(3 DOM) Ce-based catalysts were successfully prepared via a surfactant-assisted colloidal crystal template(CCT) route. The as-synthesized catalysts showed wellordered structures with macropores and small interconnected pore windows. The Raman results indicate that the catalyst persists pure fluorite cubic phases until the molar ratio of Mn exceeds 0.3, therefore MnO_x particles form and impede the contact of the active site and the reagent and restraining soot combustion. The doping of Nd into MnO_x-CeO_2 enhances the catalytic activity because of increased oxygen vacancy, Mn~(4+)content and stronger redox ability. Nd-doping also improves thermal stability of the catalyst due to less sintering and none phase separation after thermal aging. The fresh and aged Mn_(0.3)Ce_(0.6)Nd_(0.1)O_2 catalysts show the maximum oxidation rate for soot at 331 and 355 ℃ in the O_2/N_2 atmosphere, achieving a nearly 100% CO_2 selectivity.     

Effect of metal doping into Ce0.5Zr0.5O2 on catalytic activity of MnOx/Ce0.5–xZr0.5–xM0.2xOy/Al2O3 for benzene combustion

The research investigated the effect of doping two metals separately or together into Ce0.5Zr0.5O2 on the catalytic activity of MnOx/Ce0.5-xZr0.5-xM0.2xOy/Al2O3 （M=Y, Mn, Y and Mn） for catalytic combustion of benzene. The prepared catalysts were characterized by X-ray diffraction （XRD）, surface area analysis, oxygen storage capacity （OSC）, and H2-temperature programmed reduction （H2-TPR）. Catalytic test was performed on a conventional fixed bed flow reactor. The characterization results revealed that Y and Mn ions entered into the ceria-zirconia mixed oxides framework, which improved the textural properties and greatly promoted the MnOx dispersion on the support surface. The complete conversion temperature of benzene on MnOx/Ce0.4Zr0.4Y0.1Mn0.1Oy/Al2O3 was 563 K, and the selectivity of carbon dioxides was 99%. This catalyst could be applied in a wide range of GHSV and wide concentration condition, showing great potential for application.     

Effect of Metal Oxide Doping into Ce0.5Zr0.5O2 on Catalytic Activity of MnOx/γ-Al2O3/Ce0.45Zro.45M0.1Ox （M = Y, La, Mn） Honeycomb Catalysts

This article showed that the catalytic activity of MnOx/γ-Al2O3/Ce0.5Zr0.5O2 monolithic catalyst toward the catalytic combustion of ethanol in a fixed bed reactor could be greatly improved by doping three metal oxides into Ce0.5Zr0.5O2. The catalytic activity of MnOx/γ-Al2O3/Ce0.45Zr0.45M0.1 Ox （M = Y, La, Mn） is better than that of MnOx/γ-Al2O3/Ce0.5 Zr0.5O2. The order of activity of the catalysts is as follows： MnOx/γ-Al2O3/Ce0.45Zr0.45Y0.1Ox 〉 MnOc/γ-Al2O3/Ce0.45 Zr0.45La0.1Ox 〉 MnOx/γT-Al2O3/Ce0.45Zr0.45Mn0.1Ox 〉 MnOx/y-Al2O3/Ce0.5Zr0.5O2. The influence of the loading amount of manganese oxide in enhancing the catalytic activity of MnOx/γ-Al2O3/Ce0.45Zr0.45Y0.1 Ox was investigated. The results showed that when MnO2 loading amount was 10% （mass fraction）, the MnOx/Al2O3/Ce0.45Zr0.45Y0.1Ox catalyst recorded the highest activity.     

Catalytic wet oxidation of N,N-dimethyl formamide over ruthenium supported on CeO2 and Ce0.7Zr0.3O2 catalysts

A series of Ru supported on CeO₂ and Ce_0.7Zr_0.3O₂(CeZrO) was prepared by incipient-wet impregnation method and investigated in the catalytic wet oxidation of N,N-dimethyl formamide (DMF) in batch reactor. The physicochemical property of the catalysts was characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), H₂ temperature-programmed reduction (H₂-TPR), X-ray photoelectron spectroscopy (XPS) and thermogravimetry (TG). Compared with 3%Ru/CeO₂, 3%Ru/Ce_0.7Zr_0.3O₂ catalyst exhibits much higher performance for DMF degradation due to the promotion of Ru dispersion and the transfer of active oxygen, and 99% DMF conversion and 97% COD elimination are obtained at 453 K, 2.5 MPa oxygen pressure after 5 h. The reaction mechanism of DMF degradation was suggested. The carbonaceous species deposition and oxidation of Ru can be responsible for catalyst deactivation. And the catalyst activity can be recovered by air calcination and H₂ reduction.     

Structure and catalytic property of CeO2-ZrO2-Fe2O3 mixed oxide catalysts for diesel soot combustion： Effect of preparation method

A series of Ce0.5Fe0.30Zr0.20O2 catalysts were prepared by different methods(co-precipitations method, citric acid sol-gel method, impregnation method, physical mixed method, and hydrothermal method) and characterized by X-ray diffraction(XRD), Raman spectroscopy, Brunauer-Emmett-Teller(BET) and H2-TPR measurements. Potential of the catalysts in the soot oxidation was evaluated in a temperature-programmed oxidation(TPO) apparatus. The results showed that all the Fe3+ and Zr4+ were incorporated into ceria lattice to form a pure Ce-Fe-Zr-O solid solution for the co-precipitation sample, but two kinds of Fe phases existed in the Ce-Fe-Zr-O catalysts prepared by other methods: Fe3+ incorporated into CeO2 lattice and dispersed Fe2O3 clusters. The free Fe2O3 clusters could improve the activity of catalysts for soot oxidation comparing with the pure Ce-Fe-Zr-O solid solution owing to the synergetic effect between free Fe2O3 and surface oxygen vacancies. In addition, the activity of catalysts strongly relied on the surface reducibility of free Fe2O3 particles. Holding both abundant free Fe2O3 particles and high oxygen vacancy concentration, the hydrothermal Ce0.5Fe0.3Zr0.2O2 catalyst presented the lowest Ti(251 °C, ignition temperature of soot oxidation) and Tm(310 °C, maximum oxidation rate temperature) for soot combustion(with tight-contact between soot and catalysts) among the five samples. Even after aging at 800 °C for 10 h, the Ti and Tm were still relatively low, at 273 and 361 °C, respectively, indicating high catalytic stability.     

Mechanical properties,thermophysical properties and electronic structure of Yb3+ or Ce4+-doped La2Zr2O7-based TBCs

First-principles calculations based on density functional theory were performed to investigate the cohesive energies, elastic modulus, Debye temperatures, thermal conductivities and density of states of La_2−xYb_xZr₂O₇, La₂Zr_2−xCe_xO₇ and La_2−xYb_xZr_2−xCe_xO₇ (x = 0.00, 0.25, 0.50, 0.75, 1.00) ceramics. The results show that doping Yb³⁺ or Ce⁴⁺ into La₂Zr₂O₇ reduces its elastic modulus, thermal conductivity and Debye temperature. Compared with La_2−xYb_xZr₂O₇ (x ≠ 0.00), La₂Zr_2−xCe_xO₇ compounds have better ductility and lower Debye temperature. The Debye temperature values of La₂Zr_2−xCe_xO₇ (x ≠ 0.00) compounds are in the range of 485.0–511.5 K. Among all components, the fluorite-type La_2−xYb_xZr_2−xCe_xO₇ (x = 0.75, 1.00) compounds exhibit better mechanical and thermophysical properties, and their thermal conductivity values are only 1.213–1.246 W/(m∙K) (1073 K), which are 14.5%–16.7% lower than that of the pure La₂Zr₂O₇. Thus, our findings open an entirely new avenue for TBCs.     

Catalytic combustion of toluene over Pd-based monolithic catalysts with a novel washcoat Ce0.8Zr0.15La0.05Oδ

Two novel washcoats Ce_0.8Zr_0.15La_0.05O_δ and Ce_0.8Zr_0.2O₂ was prepared by an impregnation method, which acted as a host for the active Pd component to prepare Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate and Pd/Ce_0.8Zr_0.2O₂/substrate monolithic catalysts for toluene combustion. The washcoats was characterized by X-ray diffraction (XRD), Raman spectroscopy, Brunauner-Emmett-Teller (BET), and H₂-temperature-programmed reduction (H₂-TPR). The result indicated that both the washcoats had strong vibration-shock resistance according to ultrasonic test. Doping La³⁺ into CeO₂-ZrO₂ solid solution could generate more oxygen vacancies, and could inhibit the sinter of CeO₂-ZrO₂ solid solution when calcined at high temperatures (800, 900 and 1000 °C). The washcoat Ce_0.8Zr_0.15La_0.05O_δ had much better redox properties. The reductive temperature of Ce⁴⁺ species shifted to low temperature by 60 °C when the washcoats calcined at high temperatures (800, 900 and 1000 °C). The Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalyst calcination at 500 °C had the best catalytic activity and the 95% toluene conversion at a temperature as low as 190 °C. When calcined at low temperature (500 and 700 °C), the catalytic activity has little improvement, however, when calcined at high temperature, the catalytic activity of Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalysts had significant improvement. As catalyst washcoat, the Ce_0.8Zr_0.15La_0.05O_δ had better thermal stability than the washcoat Ce_0.8Zr_0.2O₂, the developed Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalyst in this work was promising for eliminating Volatile organic compounds.     

Preparation of M/Ce1–xTixO2 (M=Pt,Rh, Ru) from sol-gel method and their catalytic oxidation activity for diesel soot

A series of Ce_1–xTi_xO₂ mixed oxide catalysts were synthesized by sol-gel method and then loading of noble metal (M = Pt, Rh, Ru) was used for soot oxidation. Ti-doped Ce_1–xTi_xO₂ catalysts (x is the molar ratio of Ti/(Ti + Ce) and ranges from 0.1 to 0.5) exhibit much better oxidation performance than CeO₂ catalyst, and the Ce_0.9Ti_0.1O₂ catalyst calcined at 500 °C has the best catalysis activity. Each noble metal (1 wt%) was supported on Ce_0.9Ti_0.1O₂ (M/C9T1) and the properties of the catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman, Brunauer–Emmett–Teller (BET) method, and H₂-temperature programmed reduction (H₂-TPR) results. Results show that the introduction of Ti into CeO₂ forming Ti-O-Ce structure enhances the catalytic activity and increases the number of oxygen vacancies at the catalyst surface. The noble metal is highly dispersed over Ce_0.9Ti_0.1O₂, and M/C9T1 catalysts present enhanced activity in comparison to Ce_0.9Ti_0.1O₂. It is found that noble metals can greatly increase the activity of the catalyst and the corresponding oxidation rate of soot can enhance the electron transfer capacity and oxygen adsorption capacity of the catalyst. A small amount of Ti doping in CeO₂ can significantly improve the activity of the catalyst, while a large amount of Ti reduces the performance of the catalyst because a large amount of Ti is enriched on the surface of the catalyst, which hinders the contact and reaction between the catalyst and the soot.     

NiO-Ce0.5Zr0.5O2 catalysts prepared by citric acid method for steam reforming of ethanol

NiO-Ce0.5Zr0.5O2 catalysts were prepared by citrate method and used for hydrogen production from steam reforming of ethanol （SRE）. The effect of nickel content and space velocity on the catalytic performance was investigated. The prepared catalysts were characterized with XRD and thermal analysis techniques. 20%NiO-Ce0.5Zr0.5O2catalyst was very active and selective for hydrogen production via SRE, in which ethanol conversion of 100% could be obtained with feed component of 20% （H2O＋EtOH） and 80% N2, water/ethanol of 3/1 in molar ratio at 350 ℃. Also, the catalyst showed good stability for anti-sintering and carbon-resistance. The XRD illuminated that both NiO and Ce0.5Zr0.5O2 crystal sizes were very small in NiO-Ce0.5Zr0.5O2 catalyst, and Ce0.5Zr0.5O2 solid solution was formed.     

Effect of surface manganese oxide species on soot catalytic combustion of Ce–Mn–O catalyst

Constructing cerium and manganese bimetallic catalysts with excellent catalytic performance for soot combustion is the research frontier at present. In order to find out the key factors for catalytic soot combustion of Ce–Mn–O catalysts, a series of Ce–Mn–O catalysts with different Ce/Mn proportions were prepared by co-precipitation method. The activity test results show that it increases first and then decreases with the increase of Mn content. The best catalytic activity is obtained for Ce_0.64Mn_0.36 catalyst, which shows a maximum rate temperature (T_m) at 306 °C for CO₂ production in TPO curve. Compared with non-catalytic soot combustion, the T_m decreases by more than 270 °C. Systematical characterization results suggest that when the adsorbed surface oxygen, lattice oxygen, specific surface area and total reduction amount of the catalysts reach a certain value, the key factors leading to the difference of catalytic activity become the readily reducible and highly dispersed surface manganese oxide species and contact performance of the external surface. The surface manganese oxide species is beneficial to improving the low-temperature reducibility of catalysts and the porous surface is conducive to the contact between catalyst and soot. Furthermore, for the soot combustion reaction containing only O₂, the promoting effect of Mn⁴⁺ is not obvious.     

Helium ion irradiation effects on neodymium and cerium co-doped Gd2Zr2O7 pyrochlore ceramic

This paper studies the helium ions irradiation effects on Nd and Ce co-doped Gd_2 Zr_2 O_7 ceramics. where Nd replaces the Gd site and Ce replaces the Zr site respectively. A series of(Gd_(1-x)Nd_x)_2(Zr_(1-y)Ce_y)_2 O_7(0 ≤ x, y ≤ 1) ceramics were irradiated with a 500 keV He ions at room temperature at fluences ranging from 1 × 10~(15) to 1 × 10~(17) ions/cm~2. The irradiated samples were characterized using GIXRD, Raman and SEM measurements. From the GIXRD and Raman observations, the results indicate that all the samples display a deficient fluorite structure after irradiation. The irradiation toleration increases with the irradiation depth increasing under experimental conditions, and Nd_2 Ce_2 O_7 has the best irradiation stability in the(Gd_(1-x)Nd_x)_2(Zr_(1-y)Ce_y)_2 O_7(0≤ x. y≤1). Based on SEM results, the irradiated samples are still relatively dense and uniform, and no second phase exists.     

Er and Gd Co-Doped Ceria-Based Electrolyte Materials for IT-SOFCs Prepared by the Cellulose-Templating Method

Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) (EGDC) powders were successfully synthesized with a fast and facile cellulose-templating method for the first time and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The samples were calcined at a relatively low calcination temperature of 773 K (500 °C). The sintering behavior of the calcined EGDC powders was also investigated at 1673 K (1400 °C) for 6 hours. Calcined Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) powders and sintered Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) pellets crystallized in the cubic fluorite structure. It was found that the relative densities of the sintered EGDC pellets were over 95 pct for all the Er contents studied. Moreover, the effect of Er content on the ionic conductivity of the gadolinium-doped ceria (GDC, Ce_0.9Gd_0.1O_1.90) was investigated. The highest ionic conductivity value was found to be 3.57 × 10^?2 S cm^?1 at 1073 K (800 °C) for the sintered Ce_0.82Gd_0.1Er_0.08O_1.91 at 1673 K (1400 °C) for 6 hours.     

Effects of different introduction methods of Ce4+ and Zr4+ on denitration performance and anti-K poisoning performance of V2O5-WO3/TiO2 catalyst

The purpose of this work is to explore the effects of the introduction methods of Ce⁴⁺ and Zr⁴⁺ on the physicochemical properties, activity, and K tolerance of V₂O₅-WO₃/TiO₂ catalyst for the selective catalytic reduction of NO_x by NH₃. Four different methods, namely pre-impregnation, post-impregnation, co-impregnation, and co-precipitation, were used to synthesize a series of V₂O₅-WO₃-TiO₂-CeO₂-ZrO₂ catalysts. The catalysts were characterized by XRD, BET, NH₃-TPD, XPS, and H₂-TPR techniques. Moreover, the activity and anti-K poisoning performance were tested by an NH₃-SCR model reaction. The results show that the introduction of Ce⁴⁺ and Zr⁴⁺ can improve the catalytic performance of V₂O₅-WO₃/TiO₂ catalyst, but the impregnation method cannot enhance the anti-K poisoning performance. Ce⁴⁺ and Zr⁴⁺ introduced by co-precipitation method can effectively improve the tolerance of K, which is mainly due to the incorporation of Ce⁴⁺ and Zr⁴⁺ into TiO₂ lattice to form a uniform TiO₂-CeO₂-ZrO₂ solid solution, resulting in the optimal surface acidity and redox performance, and reducing the decreases caused by K-poisoning. Furthermore, based on the best introduction method, we further optimized the molar ratio of Ce⁴⁺/Zr⁴⁺. It is found that the catalyst exhibits the best anti-K poisoning performance when the molar ratio of Ce⁴⁺/Zr⁴⁺ is 2:1.     

CO oxidation over CuO catalysts supported on CeO2-ZrO2 prepared by microwave-assisted co-precipitation： The influence of CuO content

CeO2-ZrO2 mixed oxide(Ce0.6Zr0.4O2) prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.4O2 catalysts with various CuO contents(0 wt.%–15 wt.%) via the method of incipient-wetness impregnation.The obtained CuO/Ce0.6Zr0.4O2 samples were characterized by N2 adsorption,XRD,Raman,TEM and H2-TPR technologies,and their catalytic activities for CO oxidation were investigated.The results showed that the activity of CuO/Ce0.6Zr0.4O2 catalyst was strongly influenced by the content of CuO,and the catalyst with 10 wt.% CuO exhibited the best catalytic activity in CO oxidation,which could be attributed to the high dispersion and reducibility of CuO,and high oxygen vacancy concentration in the catalyst.     

Mn-Ce-Nb-Ox/P84 catalytic filters prepared by a novel method for simultaneous removal of particulates and NO

The Mn-Ce-Nb-O_x/P84 catalytic filter for removal of particulates and NO simultaneous was prepared by a novel method(foam coating method). The process parameters including the concentrations of PTFE emulsion, particle size of catalyst and calcination temperature for preparation of catalytic filters were analyzed. In addition, the physical properties and performance for removal of NO(NH_3-SCR) and particulates of Mn-Ce-Nb-O_x/P84 catalytic filter prepared under the optimized parameters, were also systematic studied. Results show that the process parameters had significant influences on stability and performance of catalytic filter, The Mn-Ce-Nb-O_x/P84 catalytic filter prepared by foam coating method under the optimized parameters, has satisfactory physical properties and catalytic performance for removal of NO and particulates at 140-220 ℃. The NO removal efficiency of catalytic filter can reach95.3% at 200 ℃ as the catalyst loading amount is 450 g/m~2, Moreover,the dust removal efficiency of MnGe-Nb-O_x/P84 catalytic filter reaches as high as 99.98%, and the PM2.5 removal efficiency also reaches99.98%. The anti-sulfur performance of Mn-Ce-Nb-O_x catalytic filter is also attractive, after injecting150 ppm SO_2, the NO removal efficiency still retains up to 85%. It is indicated that the foam coating method can not only make a bond of high strength between catalyst and filter, but also make the catalytic filter possessing an excellent and stable performance for removal of NO and particulates.     

Effect of calcination process on performance of 3DOM CeMnO_3 catalysts

A series of 3DOM CeMnO_3 perovskite catalysts were prepared by poly(methyl methacrylate) hardtemplating-excessive impregnation method at calcination temperature of x℃(x=600,700,800) and the heating rate of y ℃/min(y=1,2,5,10).The samples were characterized by Brunauer-Emmett-Teller method,scanning electron microscopy,transmission electron microscopy,H_2-temperature programmed reduction,X-ray photoelectron spectroscopy,X-ray diffraction,moreover,the effect of the calcination process on the catalytic activity of the samples were discussed by the catalytic combustion of toluene.The results show that the 3DOM CeMnO_3 catalysts calcined at 600℃ promote the formation of a perovskite structure,inhibit the reduction of the Mn~(4+) species in the catalyst with high temperature.The catalyst expresses the complete macroporous structure,large specific surface area(38.8 m~2/g),higher adsorption oxygen concentration and Mn~(4+) substance concentration,with a low T_(90%)=172℃.By preparing the catalysts at different calcination heating rates,it can be concluded that the catalyst possesses a high concentration of adsorbed oxygen and a low reduction temperature and a large specific surface area(40.42 m~2/g) greatly promotes adsorption stage catalytic oxidation reaction and catalytic combustion of toluene at low temperature under the heating rate of 5℃/min.When the heating rate is 1 ℃/min,the catalyst has a complete macroporous structure(250 nm),which is beneficial to the exchange of macromolecular substances during the catalytic reaction and the catalyst has a high concentration of lattice oxygen suitable for the catalysis of toluene in high temperature flue gas combustion.     

Low-temperature catalytic combustion of trichloroethylene over MnOx-CeO2 mixed oxide catalysts

The cerium-based catalysts were investigated for the catalytic co mbustion of trichlo roethylene(TCE) and exhibit a surprising catalytic activity.MnO_x was doped into CeO₂ by a citric acid(CA) sol-gel method,and the effect of Mn content on the physicochemical properties and catalytic activities of MnO_x-CeO₂ mixed oxides was investigated systemically.The introduction of MnO_x into CeO₂ can evidently improve the catalytic activity and...