Synergistic Effects of Co3O4-CeO2 Nanoparticles towards Catalytic Oxidation of Aromatic Hydrocarbons: A Study in Association with Carbon Monoxide and Humidity

In this study, a series of Co3O4-CeO2 nanocomposites with various Co3O4 loading were fabricated by the impregnation method using cobalt(II) acetate as the cobalt precursor for the treatment of benzene, toluene, ethylbenzene, and xylene (BTEX). The as-prepared Co3O4-CeO2 nanocomposites were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (O2-TPD). The excellent reproduction of active oxygen species caused by the high dispersion of Co3O4 crystals on the CeO2 supports was established. In addition, the reduction peaks of Co3O4-CeO2 nanocomposites were found at much lower temperatures compared to pure CeO2, considering their unique redox property influencing on the high catalytic activity. Among the characterized materials, the 5.0 wt.% Co3O4 supported on CeO2 (5.0Co–Ce) was the best system for catalytic oxidation of xylene, along with excellent performances in the cases of benzene, ethylbenzene, and toluene. Its catalytic activity increased in the order: benzene < xylene < ethylbenzene < toluene . Furthermore, the addition of carbon monoxide (CO) as a coreactant permitted to improve the catalytic performances in such oxidations as well as the stability of as-prepared catalysts, even under humid conditions.

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High catalytic activity for formaldehyde oxidation of an interconnected network structure composed of δ-MnO2 nanosheets and γ-MnOOH nanowires

Advances in Manufacturing ◽

10.1007/s40436-020-00321-2 ◽

2020 ◽

Vol 8 (4) ◽

pp. 429-439

Author(s):

Ying Tao ◽

Rong Li ◽

Ai-Bin Huang ◽

Yi-Ning Ma ◽

Shi-Dong Ji ◽

...

Keyword(s):

Catalytic Activity ◽

Network Structure ◽

Manganese Oxides ◽

Active Oxygen Species ◽

Low Cost ◽

High Dispersion ◽

Hydroxyl Groups ◽

High Catalytic Activity ◽

Interconnected Network ◽

Surface Hydroxyl

AbstractAmong the transition metal oxide catalysts, manganese oxides have great potential for formaldehyde (HCHO) oxidation at ambient temperature because of their high activity, nontoxicity, low cost, and polybasic morphologies. In this work, a MnO2-based catalyst (M-MnO2) with an interconnected network structure was successfully synthesized by a one-step hydrothermal method. The M-MnO2 catalyst was composed of the main catalytic agent, δ-MnO2 nanosheets, dispersed in a nonactive framework material of γ-MnOOH nanowires. The catalytic activity of M-MnO2 for HCHO oxidation at room temperature was much higher than that of the pure δ-MnO2 nanosheets. This is attributed to the special interconnected network structure. The special interconnected network structure has high dispersion and specific surface area, which can provide more surface active oxygen species and higher surface hydroxyl groups to realize rapid decomposition of HCHO.

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Highly Active CuO/KCC−1 Catalysts for Low-Temperature CO Oxidation

Processes ◽

10.3390/pr10010145 ◽

2022 ◽

Vol 10 (1) ◽

pp. 145

Author(s):

Yiwei Luo ◽

Yonglong Li ◽

Conghui Wang ◽

Jing Wang ◽

Wenming Liu ◽

...

Keyword(s):

Co Oxidation ◽

Active Oxygen Species ◽

Copper Catalysts ◽

High Dispersion ◽

Impregnation Method ◽

Active Components ◽

Highly Active ◽

Low Temperature Co Oxidation ◽

Oxidation Performance ◽

The Stability

Copper catalysts have been extensively studied for CO oxidation at low temperatures. Previous findings on the stability of such catalysts, on the other hand, revealed that they deactivated badly under extreme circumstances. Therefore, in this work, a series of KCC−1-supported copper oxide catalysts were successfully prepared by impregnation method, of which 5% CuO/KCC−1 exhibited the best activity: CO could be completely converted at 120 °C. The 5% CuO/KCC−1 catalyst exhibited better thermal stability, which is mainly attributed to the large specific surface area of KCC−1 that facilitates the high dispersion of CuO species, and because the dendritic layered walls can lengthen the movement distances from particle-to-particle, thus helping to slow down the tendency of active components to sinter. In addition, the 5% CuO/KCC−1 has abundant mesoporous and surface active oxygen species, which are beneficial to the mass transfer and promote the adsorption of CO and the decomposition of Cu+–CO species, thus improving the CO oxidation performance of the catalyst.

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CO Oxidation Efficiency and Hysteresis Behavior over Mesoporous Pd/SiO2 Catalyst

Catalysts ◽

10.3390/catal11010131 ◽

2021 ◽

Vol 11 (1) ◽

pp. 131 ◽

Cited By ~ 1

Author(s):

Rola Mohammad Al Soubaihi ◽

Khaled Mohammad Saoud ◽

Myo Tay Zar Myint ◽

Mats A. Göthelid ◽

Joydeep Dutta

Keyword(s):

Carbon Monoxide ◽

Catalytic Activity ◽

Co Oxidation ◽

Active Sites ◽

Bond Activation ◽

Dissociative Adsorption ◽

High Catalytic Activity ◽

Good Catalytic Activity ◽

Pretreatment Conditions ◽

Oxidation Efficiency

Carbon monoxide (CO) oxidation is considered an important reaction in heterogeneous industrial catalysis and has been extensively studied. Pd supported on SiO2 aerogel catalysts exhibit good catalytic activity toward this reaction owing to their CO bond activation capability and thermal stability. Pd/SiO2 catalysts were investigated using carbon monoxide (CO) oxidation as a model reaction. The catalyst becomes active, and the conversion increases after the temperature reaches the ignition temperature (Tig). A normal hysteresis in carbon monoxide (CO) oxidation has been observed, where the catalysts continue to exhibit high catalytic activity (CO conversion remains at 100%) during the extinction even at temperatures lower than Tig. The catalyst was characterized using BET, TEM, XPS, TGA-DSC, and FTIR. In this work, the influence of pretreatment conditions and stability of the active sites on the catalytic activity and hysteresis is presented. The CO oxidation on the Pd/SiO2 catalyst has been attributed to the dissociative adsorption of molecular oxygen and the activation of the C-O bond, followed by diffusion of adsorbates at Tig to form CO2. Whereas, the hysteresis has been explained by the enhanced stability of the active site caused by thermal effects, pretreatment conditions, Pd-SiO2 support interaction, and PdO formation and decomposition.

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Low platinum alloy catalyst PtCo3 obtaining high catalytic activity and stability with great water and CO2 resistance for catalytic oxidation of toluene

Fuel ◽

10.1016/j.fuel.2021.121794 ◽

2022 ◽

Vol 307 ◽

pp. 121794

Author(s):

Jianwu Zou ◽

Yankun Du ◽

Rongjia Fang ◽

Xiaoshuang Duan ◽

Yangjia Liu ◽

...

Keyword(s):

Catalytic Activity ◽

Catalytic Oxidation ◽

High Catalytic Activity ◽

Platinum Alloy ◽

Alloy Catalyst

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Effect of the ionizing radiation on the catalytic activity of the BASF K-3-10 catalyst in the low-temperature conversion of carbon monoxide by water vapour. Stability of the radiation catalytic effects

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19861571 ◽

1986 ◽

Vol 51 (8) ◽

pp. 1571-1578 ◽

Cited By ~ 26

Author(s):

Alois Motl

Keyword(s):

Carbon Monoxide ◽

Catalytic Activity ◽

Low Temperature ◽

Catalytic Effect ◽

Catalytic Properties ◽

Beta Radiation ◽

Fast Neutrons ◽

Time Interval ◽

The Stability ◽

Catalytic Effects

The radiation catalytic properties of the BASF K-3-10 catalyst were studied, namely the dependence of these effects on the time interval between the catalyst irradiation and the reaction itself and also on the length of the catalyst use. The catalytic effects decrease exponentially with the interval between the irradiation and the reaction if the catalyst is kept in the presence of air. The stability of effects induced by various types of radiations increases in the sequence beta radiation - gamma radiation - fast neutrons. The radiation catalytic effect stability in the reaction increases in the same sequence.

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High Catalytic Activity of Ion-Exchanged Nickel on Carboxymethylated Wood Char in Methanation of Carbon Monoxide

Chemistry Letters ◽

10.1246/cl.1995.699 ◽

1995 ◽

Vol 24 (8) ◽

pp. 699-700 ◽

Cited By ~ 6

Author(s):

Tsutomu Suzuki ◽

Yuzo Imizu ◽

Yoshinobu Satoh ◽

Sunao Ozaki

Keyword(s):

Carbon Monoxide ◽

Catalytic Activity ◽

High Catalytic Activity ◽

Wood Char

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LaOx Modified MnOx Loaded Biomass Activated Carbon and its Enhanced Performance for Simultaneous Abatement of NO and Hg0

10.21203/rs.3.rs-554847/v1 ◽

2021 ◽

Author(s):

Lei Yi ◽

Jinke Xie ◽

Caiting Li ◽

Jian Shan ◽

Yingyun Liu ◽

...

Keyword(s):

Catalytic Oxidation ◽

Activated Carbons ◽

Active Oxygen Species ◽

Physicochemical Characterization ◽

Acid Sites ◽

Superior Performance ◽

Bet Surface Area ◽

Impregnation Method ◽

Oxidation Activity ◽

No Removal

Abstract A battery of agricultural straw derived biomass activated carbons supported LaOx modified MnOx (LaMn/BACs) was prepared by a facile impregnation method and then tested for the efficiency of simultaneous abatement of NO and Hg0. 15%LaMn/BAC manifested excellent removal efficiency of Hg0 (100%) and NO (86.7%) at 180 °C, which also exhibited splendid resistance to SO2 and H2O. The interaction between Hg0 removal and NO removal was explored, thereinto Hg0 removal had no influence on NO removal, while NO removal preponderated over Hg0 removal. The inhibitory effect of NH3 was greater than the accelerative effect of NO and O2 on Hg0 removal. The physicochemical characterization of related samples were characterized by SEM, XRD, BET, H2-TPR, NH3-TPD and XPS. After incorporating suitable LaOx into 15%Mn/BAC, the synergistic effect between LaOx and MnOx contributed to the improvement of BET surface area and total pore volume, the promotion of redox ability, surface active oxygen species and acid sites, inhibiting the crystallization of MnOx. 15%LaMn/BAC has the best catalytic oxidation activity at low temperature. That might be answerable for superior performance and preferable tolerance to SO2 and H2O. Finally, the principle of catalytic oxidation was also discussesed in this article.

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CO Oxidation over Metal Oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2) Doped CuO-Based Catalysts Supported on Mesoporous Ce0.8Zr0.2O2 with Intensified Low-Temperature Activity

Catalysts ◽

10.3390/catal9090724 ◽

2019 ◽

Vol 9 (9) ◽

pp. 724 ◽

Cited By ~ 4

Author(s):

Yan Cui ◽

Leilei Xu ◽

Mindong Chen ◽

Chufei Lv ◽

Xinbo Lian ◽

...

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Metal Oxide ◽

Metal Oxides ◽

Co Oxidation ◽

Active Sites ◽

Earth Metal ◽

High Dispersion ◽

Impregnation Method ◽

X Ray

CuO-based catalysts are usually used for CO oxidation owing to their low cost and excellent catalytic activities. In this study, a series of metal oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2)-doped CuO-based catalysts with mesoporous Ce0.8Zr0.2O2 support were simply prepared by the incipient impregnation method and used directly as catalysts for CO catalytic oxidation. These mesoporous catalysts were systematically characterized by X-ray powder diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), energy-dispersed spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS), and H2 temperature programmed reduction (H2-TPR). It was found that the CuO and the dopants were highly dispersed among the mesoporous framework via the incipient impregnation method, and the strong metal framework interaction had been formed. The effects of the types of the dopants and the loading amounts of the dopants on the low-temperature catalytic performances were carefully studied. It was concluded that doped transition metal oxides could regulate the oxygen mobility and reduction ability of catalysts, further improving the catalytic activity. It was also found that the high dispersion of rare earth metal oxides (PrO2, Sm2O3) was able to prevent the thermal sintering and aggregation of CuO-based catalysts during the process of calcination. In addition, their presence also evidently improved the reducibility and significantly reduced the particle size of the CuO active sites for CO oxidation. The results demonstrated that the 15CuO-3Fe2O3/M-Ce80Zr20 catalyst with 3 wt. % of Fe2O3 showed the best low-temperature catalytic activity toward CO oxidation. Overall, the present Fe2O3-doped CuO-based catalysts with mesoporous nanocrystalline Ce0.8Zr0.2O2 solid solution as support were considered a promising series of catalysts for low-temperature CO oxidation.

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Catalytic Oxidation of Chlorobenzene over Pd-TiO2 /Pd-Ce/TiO2 Catalysts

Catalysts ◽

10.3390/catal10030347 ◽

2020 ◽

Vol 10 (3) ◽

pp. 347 ◽

Cited By ~ 1

Author(s):

Wenjun Liang ◽

Xiaoyan Du ◽

Yuxue Zhu ◽

Sida Ren ◽

Jian Li

Keyword(s):

Catalytic Activity ◽

Catalytic Oxidation ◽

Calcination Temperature ◽

Catalyst Activity ◽

Space Velocity ◽

Impregnation Method ◽

Tio2 Catalyst ◽

Metal Support ◽

Oxidation Efficiency

A series of Pd-TiO2/Pd-Ce/TiO2 catalysts were prepared by an equal volume impregnation method. The effects of different Pd loadings on the catalytic activity of chlorobenzene (CB) were investigated, and the results showed that the activity of the 0.2%-0.3% Pd/TiO2 catalyst was optimal. The effect of Ce doping enhanced the catalytic activity of the 0.2% Pd-0.5% Ce/TiO2 catalyst. The characterization of the catalysts using BET, TEM, H2-TPR, and O2-TPD showed that the oxidation capacity was enhanced, and the catalytic oxidation efficiency was improved due to the addition of Ce. Ion chromatography and Gas Chromatography-Mass Spectrometer results showed that small amounts of dichlorobenzene (DCB) and trichlorobenzene (TCB) were formed during the decomposition of CB. The results also indicated that the calcination temperature greatly influenced the catalyst activity and a calcination temperature of 550 °C was the best. The concentration of CB affected its decomposition, but gas hourly space velocity had little effect. H2-TPR indicated strong metal–support interactions and increased dispersion of PdO in the presence of Ce. HRTEM data showed PdO with a characteristic spacing of 0.26 nm in both 0.2% Pd /TiO2 and 0.2% Pd-0.5% Ce/TiO2 catalysts. The average sizes of PdO nanoparticles in the 0.2% Pd/TiO2 and 0.2% Pd-0.5% Ce/TiO2 samples were 5.8 and 4.7 nm, respectively. The PdO particles were also deposited on the support and they were separated from each other in both catalysts.

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Activity of yFe-10Cu/H-Sep and xCu/H-Sep for the Selective Catalytic Reduction of NO with Propylene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.281 ◽

2012 ◽

Vol 518-523 ◽

pp. 281-284

Author(s):

Qing Ye ◽

Hai Ping Wang ◽

Hai Xia Zhao ◽

Shui Yuan Cheng ◽

Tian Fang Kang

Keyword(s):

Catalytic Reduction ◽

Catalytic Performance ◽

High Dispersion ◽

High Catalytic Activity ◽

Incipient Wetness Impregnation ◽

Impregnation Method ◽

Promotional Effect ◽

Scr Of No ◽

Metal Support Interaction ◽

Metal Support

Cu supported on acid-treated sepiolite catalysts (xCu/H-Sep, x = 0  20.0 wt%) or Cu-Fe mixed supported on acid-treated sepiolite catalysts (yFe-10Cu/H-Sep, y = 0  20.0 wt%) were prepared by the incipient wetness impregnation method. The xCu/H-Sep and yFe-10Cu/H-Sep catalysts were characterized by means of XRD, BET, XRF, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the SCR of NO with propylene. XPS and XRD results indicate that there was the co-presence of Cu+-Cu2+ and Fe2+-Fe3+ over the surfaces of yFe-10Cu/H-Sep catalysts, and there was a strong interaction between Cu, Fe and sepiolite. High promotional effect of iron additive on the catalytic performance of Cu/H-Sep catalyst were found in C3H6-SCR of NO reaction. The highest activity of 65% NO conversion was obtained over 15Fe-10Cu/H-Sep catalyst at 280 oC under the condition of 1000 ppm NO, 1000 ppm C3H6, and 5% O2. The high catalytic activity of 15Fe-10Cu/H-Sep catalyst for NO reduction was due to its high reducibility to activate C3H6 to selectively reduce NO in the presence of excess O2. The high dispersion of copper oxides and strong metal-support interaction over 15Fe-10Cu/H-Sep catalyst also improve its catalytic performance.

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