Physicochemical properties of manganese-containing oxides with a spinel structure prepared with the use of ammonium nitrate and their catalytic activity in carbon monoxide oxidation

Morozov, Igor; Lyubushkin, R. A.; Fedorova, Anna; Petrov, M. N.; Burdeinaya, T. N.; Trets’yakov, V. F.

doi:10.1134/s002315840601006x

Cited by 9 publications

(16 citation statements)

References 7 publications

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“…Among them, spinel structured oxides possess advantages over the perovskites and the hopcalite, such as high stability and facile synthesis 4 . Besides, the electron exchange between neighboring cations in spinel oxides can be also optimized for promoting their catalytic ability 5,6 . The catalytic performances of mixed spinel oxides for the oxidation reaction are very often dependent, inter alia, on the composition, morphology, structure of the materials, coordination environment of the cations, and so on 7,8 .…”

Section: Introductionmentioning

confidence: 99%

“…Great efforts on the catalytic mechanisms related to those factors thereby have been made and some remarkable progress has been gained. Particularly in the spinel oxides, octahedral sites on the surface have been suggested to be the primary active sites 6,7,9 . For example, the investigation on CO oxidation by both Co3O4 nanorods and nanoparticles revealed that octahedrally coordinated Co 3+ are the active species 9 .…”

Section: Introductionmentioning

confidence: 99%

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Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction

et al. 2018

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Transition metal oxides are of potential alternatives to precious metal catalysts for oxidation reactions. Among these earth abundant oxide catalysts, cobalt-or manganese-based spinel oxides have gained consistent interests due to their superior catalytic performances. It has been found that the octahedral sites in spinels are responsible for their catalytic activities. However, little is known to date about the parameters of the octahedrally coordinated cations that influence their activity. Herein, a series of ZnMnxCo2-xO4 (x=0~2.0) spinel oxides are investigated, employing CO oxidation as the model reaction, with the particular attention on the activity variation caused by tuning the ratio of octahedrally occupied Mn to Co. Both Mn and Co contribute to the activity with Mn cations as the primary active species when they co-exist, the intrinsic specific activity is found composition-dependence and the highest activity is given by the Mn/Co molar ratio of 0.11. The presence of Mn 4+ and Mn 3+ in a proper ratio is another key for achieving high oxidation activity and can be rationalized by the moderate oxygen adsorption during the CO oxidation, which facilitates the O vacancy refilling. This is also supported by the density function theory (DFT) calculation, showing that the high activity of ZnMn0.2Co1.8O4 originates from having the O p-band center neither too far nor too close to the Fermi level. The eg occupancy of Mn cations and the O p-band center relative to the Fermi level, which are the indexes of how the electronic structure influences the oxygen addition-and removal-related processes, are proposed to serve as the activity descriptors. This work may provide a different insight into the understanding of the activity of transition metal spinel oxides for oxidation reactions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction

et al. 2018

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“…The positive influence of ammonium nitrate on sCMO formation from metal nitrate precursors and the sCMO’s activity in CO oxidation have been described. 23 We supposed that during heating molten NH 4 NO 3 rise to a liquid film that could increase the mobility of ions and resulted in the formation of the sCMO product. However, the XRD investigation of sample A500-1h (washed with water before heating) showed that the sCMO:bCMO ratio was almost the same as in sample B500-1h, thus the accumulation of sCMO might not be attributed directly to the presence of NH 4 NO 3 .…”

Section: Resultsmentioning

confidence: 99%

“…The metal-content (Cu and Mn) was determined by gravimetry as 8-oxyquinolinate or inductively coupled plasma (ICP) measurement following the standard procedure. 22 , 23 …”

Section: Methodsmentioning

confidence: 99%

“…A key point of these syntheses is the application of liquid solvents as heat-absorbing media, which can control the decomposition temperature via the evaporation of solvent to absorb the reaction heat evolved. 19 − 23 Using CHCl 3 and CCl 4 as heat-absorbing media, the solid-phase redox reaction of [Cu(NH 3 ) 4 ](MnO 4 ) 2 can be performed at 61 and 77 °C, respectively. During the reaction CuMn 2 O 4 and NH 4 NO 3 are formed, both of which are insoluble in chloroform and carbon tetrachloride.…”

Section: Introductionmentioning

confidence: 99%

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Temperature-Limited Synthesis of Copper Manganites along the Borderline of the Amorphous/Crystalline State and Their Catalytic Activity in CO Oxidation

et al. 2021

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Copper manganese oxides (CMO) with CuMn2O4 composition are well-known catalysts, which are widely used for the oxidative removal of dangerous chemicals, e.g., enhancing the CO to CO2 conversion. Their catalytic activity is the highest, close to those of the pre-crystalline and amorphous states. Here we show an easy way to prepare a stable CMO material at the borderline of the amorphous and crystalline state (BAC-CMO) at low temperatures (<100 °C) followed annealing at 300 °C and point out its excellent catalytic activity in CO oxidation reactions. We demonstrate that the temperature-controlled decomposition of [Cu(NH3)4](MnO4)2 in CHCl3 and CCl4 at 61 and 77 °C, respectively, gives rise to the formation of amorphous CMO and NH4NO3, which greatly influences the composition as well as the Cu valence state of the annealed CMOs. Washing with water and annealing at 300 °C result in a BAC-CMO material, whereas the direct annealing of the as-prepared product at 300 °C gives rise to crystalline CuMn2O4 (sCMO, 15–40 nm) and ((Cu,Mn)2O3, bCMO, 35–40 nm) mixture. The annealing temperature influences both the quantity and crystallite size of sCMO and bCMO products. In 0.5% CO/0.5% O2/He mixture the best CO to CO2 conversion rates were achieved at 200 °C with the BAC-CMO sample (0.011 mol CO2/(m2 h)) prepared in CCl4. The activity of this BAC-CMO at 125 °C decreases to half of its original value within 3 h and this activity is almost unchanged during another 20 h. The BAC-CMO catalyst can be regenerated without any loss in its catalytic activity, which provides the possibility for its long-term industrial application.

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Catalytic Oxidation of Carbon Monoxide over Transition Metal Oxides

2010

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International audienceOxidation into CO2 is a major solution to CO abatement in air depollution treatments. The development of catalytic converters led to an extraordinary high number of publications on metal catalysts during the last fifty years. Due to the increasing price of noble metals and to remarkable progresses in oxide syntheses, catalytic oxidation of carbon monoxide over oxide catalysts has recently gained in interest, even if some oxides are known to present remarkable activity since the beginning of the 20th century. In this Review, the kinetics and mechanism of CO oxidation on single and mixed oxides are examined, alongside the catalyst structure

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Physicochemical properties of manganese-containing oxides with a spinel structure prepared with the use of ammonium nitrate and their catalytic activity in carbon monoxide oxidation

Cited by 9 publications

References 7 publications

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction

Temperature-Limited Synthesis of Copper Manganites along the Borderline of the Amorphous/Crystalline State and Their Catalytic Activity in CO Oxidation

Catalytic Oxidation of Carbon Monoxide over Transition Metal Oxides

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Physicochemical properties of manganese-containing oxides with a spinel structure prepared with the use of ammonium nitrate and their catalytic activity in carbon monoxide oxidation

Cited by 9 publications

References 7 publications

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMnxCo2–xO4 Oxides for the Oxidation Reaction

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMnxCo2–xO4 Oxides for the Oxidation Reaction

Temperature-Limited Synthesis of Copper Manganites along the Borderline of the Amorphous/Crystalline State and Their Catalytic Activity in CO Oxidation

Catalytic Oxidation of Carbon Monoxide over Transition Metal Oxides

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Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction

Identifying Influential Parameters of Octahedrally Coordinated Cations in Spinel ZnMn_xCo_2–xO₄ Oxides for the Oxidation Reaction