Transition metal doped cryptomelane-type manganese oxide for low-temperature catalytic combustion of dimethyl ether

Sun, Ming; Yu, Lin; Ye, Fei; Diao, Guowang; Qian, Yu; Hao, Zhifeng; Zheng, Yuying; Yuan, Lixiang

doi:10.1016/j.cej.2013.01.061

Cited by 130 publications

(54 citation statements)

References 49 publications

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“…As shown in Figure b, the H 2 ‐TPR profile of undoped K‐OMS‐2 presents an overlapped and dispersive band in the range of T =250 to 400 °C, with a marked shoulder at approximately 260 °C. Normally, the reduction process of MnO 2 comprises three steps, including reduction of surface oxygen species (≈230 °C), reduction of MnO 2 to Mn 3 O 4 (≈295 °C), and subsequent transformation of Mn 3 O 4 into MnO (≈395 °C) . After the introduction of Co, the TPR profile is clearly shifted downward and is split into approximately three elementary bands, which suggests that the Co ions greatly modify the redox properties of K‐OMS‐2 and the mobility of active oxygen species.…”

Section: Figurementioning

confidence: 99%

Cobalt‐Doped K‐OMS‐2 Nanofibers: A Novel and Efficient Water‐Tolerant Catalyst for the Oxidation of Carbon Monoxide

et al. 2017

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Cobalt-doped manganese octahedral molecular sieves with an ordered cryptomelanes tructure (OMS-2) were synthesized by ao ne-step hydrothermalm ethod. The cobalt precursor was directly added into the solution before crystallization to allow its incorporation into the mixed-valent framework of K-OMS-2. The structure, redox properties, and surface hydrophobicity of Co-doped K-OMS-2 were examined by X-ray diffraction, FTIR spectroscopy,R amans pectroscopy,S EM,T EM, N 2 sorption, temperature-programmed reduction by H 2 ,X -ray photoelectron spectroscopy,a nd water contact-angle system. The incorporation of Co induced am orphological change in K-OMS-2 from nanorods to nanofibers and an increase in the specific surfacea rea from 70.6 to 188.3 m 2 g À1 .C o-doped K-OMS-2 was shown to be able to completely convert CO at 100 8Ci nt he presenceo fa pproximately 3% water vapor.T he promotion effect of Co on the catalytic activity is believed to originate from the enhanced redox capacity and surfacea rea of K-OMS-2, whereas the improved surfaceh ydrophobicity may induce superiorw ater-tolerant performance.CatalyticC Oo xidation hasb een extensively investigated and has already been applied in the field of air purification,a utomotive exhaust cleaning, CO removal of cigarettes moke, and CO 2 lasers. [1] However,f or the above purposes, the presence of water vapor inevitably leads to catalystd eactivation through temporary poisoning of the exposed active sites. [2] Such strict operation conditions have thus stimulated an increase in the demandt od evelop highly efficient and water-tolerantc atalysts for CO oxidation. Noble-metal catalysts such as Pd, Pt, and Au have been widely recognized as preferred choices, but both high costs and finite resources limit their application. [3] Alternatively,aseries of cheap transition-metal oxides (i.e.,C uO,

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Section: Figurementioning

confidence: 99%

Cobalt‐Doped K‐OMS‐2 Nanofibers: A Novel and Efficient Water‐Tolerant Catalyst for the Oxidation of Carbon Monoxide

et al. 2017

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“…The different oxidation states of manganese provide OMS-2 with significant advantages as a redox medium for the removal of organic pollutants. To improve the catalytic activity, OMS-2 was usually doped by foreign metal ions, such as Fe 3+ , Co 2+ , Cu 2+ , V 5+ and Mo 6+ [9,10]. The metal dopants can be loaded on the surface, incorporated into the framework, or entered into the tunnel of OMS-2 by different preparation processes, such as ball milling, impregnation, reflux, and hydrothermal methods [11,12].…”

Section: Introductionmentioning

confidence: 99%

Enhanced catalytic degradation of ciprofloxacin over Ce-doped OMS-2 microspheres

Zhang

Lyu

2016

Applied Catalysis B: Environmental

121

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“…Sun et al [11] prepared K-OMS-2 materials by solidstate and reflux methods to study the catalytic oxidation of toluene. The results established that K-OMS-2 prepared by the refluxing method exhibited higher catalytic activity than that by the solid-state reaction method.…”

Section: Introductionmentioning

confidence: 99%

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

et al. 2016

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Manganese-based octahedral molecular sieves of the type K-OMS-2 (cryptomelane structure) were prepared via reflux method by synproportionation of KMnO 4 and Mn 2? in acidic aqueous suspension. For this method, different manganese anions (sulphate, chloride and acetate) were used, which exert a strong influence on the prepared materials. Several techniques such as X-ray diffraction, Fourier transformer infrared, Raman spectroscopy, transmission electron microscopy, differential and gravimetric thermal analysis and H 2 -temperature programmed reduction were used to characterize the prepared samples. The results revealed that the prepared samples were mainly pure mono-phase cryptomelane materials. The obtained K-OMS-2 material on using the sulphate anion has more available lattice oxygen as compared to that prepared by the other anions. The catalytic activity of the prepared samples was tested towards the oxidative dehydrogenation of cyclohexane. Over the K-OMS-2RS sample, cyclohexane conversion was significantly higher than the other prepared samples.

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Transition metal doped cryptomelane-type manganese oxide for low-temperature catalytic combustion of dimethyl ether

Cited by 130 publications

References 49 publications

Cobalt‐Doped K‐OMS‐2 Nanofibers: A Novel and Efficient Water‐Tolerant Catalyst for the Oxidation of Carbon Monoxide

Cobalt‐Doped K‐OMS‐2 Nanofibers: A Novel and Efficient Water‐Tolerant Catalyst for the Oxidation of Carbon Monoxide

Enhanced catalytic degradation of ciprofloxacin over Ce-doped OMS-2 microspheres

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

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