Synthesis and characterization of Mn–MCM-41and Zr–Mn-MCM-41

Selvaraj, Manickam; Sinha, Pradeep K.; Lee, Keunwook; Ahn, Ik Sung; Pandurangan, A.; Lee, Tai Gyu

doi:10.1016/j.micromeso.2004.10.004

Cited by 109 publications

(64 citation statements)

References 45 publications

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“…These highly ordered pore systems with tunable pore sizes, large specific surface areas and pore volumes, and high density of surface silanols [2] provide excellent opportunities in inclusion chemistry [3,4]. A large number of elements such as Al [5], Ni [6,7], Cr [8], Fe [9], Mn [10,11], Ti [12][13][14], Au [15,16], Pb [17] and also others [18] have been introduced in the silicate framework. Substitution with Ti is particularly interesting because of the success of Ti-substituted zeolites in the oxidation of various organic substrates [19,20].…”

Section: Introductionmentioning

confidence: 99%

Effects of different Ti-doping methods on the structure of pure-silica MCM-41 mesoporous materials

Zhang

et al. 2008

Applied Surface Science

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Section: Introductionmentioning

confidence: 99%

Effects of different Ti-doping methods on the structure of pure-silica MCM-41 mesoporous materials

Zhang

et al. 2008

Applied Surface Science

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“…4. In general, the cyclohexanone selectivity decreases with increasing temperature [29,30]. However the selectivity for cyclohexene is increased with temperature.…”

Section: Resultsmentioning

confidence: 93%

Mn–MCM-41 molecular sieves: a selective gas-phase cyclohexanol oxidation catalyst

Santhanaraj

Suresh

Vijayan

et al. 2010

Reac Kinet Mech Cat

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Mn-MCM-41 was synthesized by the hydrothermal method. The synthesized material was characterized by various physicochemical techniques such as small angle X-ray diffraction, elemental analysis, Fourier transform infrared spectroscopy and diffuse reflectance ultraviolet-visible spectroscopy. The gas-phase cyclohexanol and air reaction over Mn-MCM-41 molecular sieve was studied for the first time. The conversion is almost constant even up to 5 h, and follows a parabolic behavior with respect to temperature. The conversion reaches a maximum at 350°C and selectivity towards cyclohexene is increased with temperature. The conversion and cyclohexene selectivity were increased with flow rate.

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“…The intensity of the bands at around 350 and 500 nm increases after calcination. These bands have been attributed to the charge transition of O 2− → Mn 3+ in the Mn 3 O 4 of octahedral coordination of Mn, and Mn 2+ located on the surface (Selvaraj et al 2005;Velu et al 1999). The introduction of gold increases the intensity of absorption peaks.…”

Section: Resultsmentioning

confidence: 99%

The properties of gold catalysts precursors adsorbed on the MCM-41 materials modified with Mn and Fe oxides

et al. 2008

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Silica mesoporous materials modified with manganese and iron were obtained by the hydrothermal method. Gold was introduced to pure and modified silica materials by the direct hydrothermal and impregnation methods. Nitrogen adsorption/desorption studies evidenced formation of the materials with large total surface area and mesoporous structure. Unmodified silica materials showed regular pore arrangement. The uniform porous structure was distorted in the iron or manganese containing samples. XRD, UV-Vis/DRS spectroscopy and temperature programmed reduction studies revealed changes of the nature of transition metal oxide and gold species on the different preparation stages. The oxide species after drying were strongly dispersed and partially incorporated to the silica framework. High temperature treatment led to the formation of extraframework Mn and Fe oxide species. Complex processes of gold deposition were observed during hydrothermal synthesis and impregnation of modified silica materials. The increase of the size of gold species was observed during cal-W. Gac ( ) cination. The presence of transition metal oxides decreased sintering of gold crystallites.

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Synthesis and characterization of Mn–MCM-41and Zr–Mn-MCM-41

Cited by 109 publications

References 45 publications

Effects of different Ti-doping methods on the structure of pure-silica MCM-41 mesoporous materials

Effects of different Ti-doping methods on the structure of pure-silica MCM-41 mesoporous materials

Mn–MCM-41 molecular sieves: a selective gas-phase cyclohexanol oxidation catalyst

The properties of gold catalysts precursors adsorbed on the MCM-41 materials modified with Mn and Fe oxides

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