Nanocrystalline AMn2O4 (A=Co, Ni, Cu) spinels for remediation of volatile organic compounds—synthesis, characterization and catalytic performance

Hosseini, Seyed Abolfazl; Niaei, Aligholi; Salari, Dariush; Nabavi, Seyed Reza

doi:10.1016/j.ceramint.2011.09.057

Cited by 105 publications

(41 citation statements)

References 30 publications

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“…The second peak appears above 500 C and is attributed to reduction of Co 2þ to metallic cobalt since its intensity increases with increase of catalyst cobalt content. These findings are in agreement with the works of Hosseini et al [13,14], who synthesized CoMn 2 O 4 spinel oxide by a solegel combustion method. Its TPR profile contained one peak at 410e420 C and one above 600 C. Bordeneuve et al [15] performed structural studies applied to the whole range of the Mn 3Àx Co x O 4 system.…”

Section: Resultssupporting

confidence: 95%

Steam reforming of methanol over cobalt catalysts: Effect of cobalt oxidation state

Papadopoulou

Ioannides

2015

International Journal of Hydrogen Energy

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Section: Resultssupporting

confidence: 95%

Steam reforming of methanol over cobalt catalysts: Effect of cobalt oxidation state

Papadopoulou

Ioannides

2015

International Journal of Hydrogen Energy

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“…(b), the presence of Ni greatly shifted the reduction temperatures to lower regions, revealing how the addition of Ni could improve the reducibility of Mn‐Ni composite oxides. In addition, the effect exerted by higher proportions of easily reduced surface‐adsorbed oxygen species on Mn‐Ni composite oxides according to XPS analysis results should be taken into consideration . Moreover, the H2‐TPR profiles of Mn‐Ni composite oxides exhibit not too much difference that of sample Mn, revealing the strong interactions between Mn and Ni species also means the synergistic effects in Mn‐Ni composite oxides, and this synergixtic effects have been proven to be beneficial to the catalytic oxidation of benzene.…”

Section: Resultsmentioning

confidence: 99%

Effective low‐temperature catalytic abatement of benzene over porous Mn‐Ni composite oxides synthesized via the oxalate route

Guo

Zhi

et al. 2019

J of Chemical Tech & Biotech

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BACKGROUND Benzene (C6H6) is a typical kind of volatile organic compound (VOC) which can exert great harm to both human health and the environment, and, thus, which needs to be eliminated before its emission. In this work, porous manganese–nickel (Mn‐Ni) composite oxide catalysts were synthesized through the oxalate route and applied to thermal catalytic oxidation of C6H6. By means of activity tests and relative physico‐chemical characterizations, the factors affecting the activity of those Mn‐Ni composite oxides were explored. RESULTS Nitrogen (N2)‐adsorption/desorption and X‐ray photoelectron spectroscopy (XPS) measurements indicated that the Brunauer–Elmett–Teller (BET) surface area and the content of surface‐adsorbed oxygen species were increased due to the addition of Ni into Mn oxide (MnOx). Meanwhile, the oxygen mobility and reducibility also were improved in the Mn‐Ni composite oxides. Accordingly, compared with MnOx, the Mn‐Ni catalysts showed higher activity for thermal catalytic oxidation of C6H6. Moreover, porous Mn‐Ni composite oxides with a Mn:Ni molar ratio of 4:1 (Mn4Ni1) displayed the best catalytic activity. Further investigation indicated that the excellent catalytic performance of Mn4Ni1 composite oxides could be ascribed mainly to the larger BET surface area and the richer content of surface‐adsorbed oxygen species, as well as stronger oxygen mobility and better reducibility compared with other Mn‐Ni catalysts. CONCLUSIONS The Mn4Ni1 composite oxides showed a lowest T90 value of 172 °C (C6H6 concentration 200 ppm, WHSV 60 000 mL g−1 h−1) among all of the obtained Mn‐Ni composite oxides. Moreover, it also exhibited favourable catalytic stability at 210 °C in the presence or absence of moisture. © 2019 Society of Chemical Industry

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“…Sin embargo, se registró una ligera diferencia en el 100 % de la conversión del 2-propanol hasta CO 2 , pues sobre el CPMn este valor se alcanzó a 320 °C mientras que sobre ACMn se logró a 300°C. Se sabe que la oxidación de los COV puede llevarse a cabo a través de un mecanismo redox de Mars Van Krevelan, en el cual la molécula orgánica es oxidada por los oxígenos de red más cercanos a la superficie del óxido, causando, a la vez, la reducción de este último, el cual vuelve a oxidarse por la presencia de oxígeno en fase gaseosa (Hosseini, et al, 2012), lo que evidencia la existencia de una relación entre el comportamiento catalítico y las propiedades de redox de los catalizadores.…”

Section: Actividad Catalíticaunclassified

Catalizadores de manganeso sintetizados por autocombustión y coprecipitación y su empleo en la oxidación del 2-propanol

Castaño

Molina

Moreno

2015

Rev. Acad. Colomb. Cienc. Ex. Fis. Nat.

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ResumenSe sintetizaron óxidos mixtos de manganeso a través de las metodologías de autocombustión y coprecipitación manteniendo constantes las relaciones Mn 2+ /Mg 2+ =1 y M 2+ /M 3+ =3, las cuales son características de los óxidos obtenidos a través de la descomposición térmica de precursores del tipo de la hidrotalcita. Los catalizadores se caracterizaron mediante las técnicas de fluorescencia de rayos X (FRX), difracción de rayos X (DRX), microscopía electrónica de barrido (SEM), adsorción de N 2 , reducción a temperatura programada y se evaluaron en la oxidación catalítica del 2-propanol. Los resultados evidenciaron que el empleo de la autocombustión como método de síntesis permite generar óxidos con propiedades estructurales, texturales, de reducción-oxidación (redox) y catalíticas similares a las obtenidas para el óxido preparado a través del precursor tipo hidrotalcita. El desempeño catalítico de los óxidos mixtos se asoció directamente con sus propiedades redox. El óxido de manganeso obtenido por autocombustión se depositó sobre monolitos metálicos de FeCrAlloy y se evaluó el efecto de la adherencia de la fase activa por medio del recubrimiento previo de los materiales con alúmina coloidal. La oxidación del 2-propanol sobre el monolito evidenció que no hay pérdida de actividad cuando el catalizador está sobre un material estructurado.Palabras clave: hidrotalcita, autocombustión, coprecipitación, monolito, COV. Self-combustion and Co-precipitation manganese catalysts and their use in the oxidation of 2-propanol AbstractManganese mixed oxides were synthesized by self-combustion and co-precipitation, maintaining constant the relationship Mn 2 + / Mg 2 + = 1 and M 2 + / M 3 + = 3, which are characteristic of the oxides obtained by thermal decomposition of hydrotalcite-like precursors. The catalysts were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), N 2 adsorption, and temperature-programmed reduction, and they were evaluated in the catalytic oxidation of 2 -propanol. The results showed that the use of such self-combustion synthesis method allows generating oxides with structural, textural, redox and catalytic properties similar to those obtained for the oxide prepared via a hydrotalcite-like precursor. The catalytic performance of mixed oxides was directly related to their redox properties. We evaluated the manganese oxide obtained by self-combustion deposited on Fecralloy metal monoliths, as well as the effect of the adhesion of the active phase of the precoat materials using colloidal alumina. The oxidation of 2-propanol over the monolith showed that there is no loss of activity when a catalyst is on a structured material.

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Nanocrystalline AMn2O4 (A=Co, Ni, Cu) spinels for remediation of volatile organic compounds—synthesis, characterization and catalytic performance

Cited by 105 publications

References 30 publications

Steam reforming of methanol over cobalt catalysts: Effect of cobalt oxidation state

Steam reforming of methanol over cobalt catalysts: Effect of cobalt oxidation state

Effective low‐temperature catalytic abatement of benzene over porous Mn‐Ni composite oxides synthesized via the oxalate route

Catalizadores de manganeso sintetizados por autocombustión y coprecipitación y su empleo en la oxidación del 2-propanol

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