Physico-chemical and catalytic properties of Zr- and Cu–Zr ion-exchanged H-MCM-41

Nieminen, Ville; Karhu, Hannu; Kumar, Narendra; Heinmaa, Ivo; Ek, Paul; Samoson, Ago; Salmi, Tapio; Murzin, Dmitry Yu.

doi:10.1039/b404176c

Cited by 10 publications

(9 citation statements)

References 36 publications

(64 reference statements)

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“…3. 29 Si NMR spectra of oxides generally exhibit three peaks for different environments for Si: isolated silanol groups (SiO) 3 Si-OH, Q 3 ; geminal silanols (SiO) 2 Si-(OH) 2 , Q 2 ; and silicon in the siloxane binding environment without hydroxyl groups (SiO) 4 Si, Q 4 [23][24][25][26][27][28]. For pure SBA-15, (Fig.…”

Section: Resultsmentioning

confidence: 97%

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

et al. 2008

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Single oxides of Ti and Zr incorporated SBA-15 were prepared and characterized by N 2 adsorption, NMR, and XPS techniques. 29 Si MAS NMR results suggest the formation of Si-O-X linkages (X: Ti or Zr) by an increase in the ratio of Q 3 /Q 4 in the presence of Ti or Zr. XPS analysis of Ti-SBA-15 catalysts indicate the presence of Ti-O-Si bonds in addition to Ti-O-Ti and Si-O-Si bonds, supporting the NMR evidence.

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Section: Resultsmentioning

confidence: 97%

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

et al. 2008

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“…On the other hand, H-MCM-41 is considered as a mildly acidic material having negligible amount of the strong Brønsted acid sites [28]. Furthermore, it is clear that the number of Brønsted acid sites is remarkably decreased after the Cu ion-exchange [19,21]. The difference in the acidity between H-MCM-41 and proton forms of the zeolites is the probable reason for the observed difference in the product distribution.…”

Section: Effect Of Copper Ion-exchangementioning

confidence: 84%

“…[19][20][21]. The thorough characterization of the materials is also described in the aforementioned references.…”

Section: Synthesis and Characterization Of Cu-modified H-zsm-5 H-betmentioning

confidence: 99%

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Radioisotopic tracing of methanol transformation using 11C-labelled methanol over copper ion-exchanged H-ZSM-5, H-Beta and H-MCM-41

et al. 2007

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Short half-life 11 C-radioisotope tracer in methanol form was used to study the transformation of methanol over copper ionexchanged H-ZSM-5, H-Beta and H-MCM-41 catalysts. The progresses of adsorption and desorption as well as methanol transformation were followed by radiodetection. The reaction products were analyzed by radio-gas chromatography. The GC analysis was completed with a radiodetector that could distinguish the radiolabelled derivates from other non-radioactive compounds, reagents or impurities. The radiodetector can be more sensitive to detect smaller amount of compound than the thermal conductivity detector or flame ionization detector since the intensity of a radio-signal is independent on thermal conductivity or ionization energy of compounds. The copper introduction into the catalysts had an inhibitory effect on the reaction to proceed further from the equilibration with the methanol and dimethyl ether resulting in hydrocarbons C 3 -C 6 . Presence of copper also allowed a possible reaction route for methanol to give formaldehyde and methyl formate.

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“…(3) Lowering of electron-hole recombination Photo luminescence emission spectra describes the migration, charge transfer carriers to the surface the composite and the of electron-hole pair recombination in the semiconductor catalysts. PL emission spectra can record the separation capacity of the photo-induced charge carriers and improve the quantum yield of the photocatalyst [49]. Hence, there is a minimum electron-hole recombination found in a noble material.…”

Section: Factors Affecting the Enhancement Of Photo-reduction Activitmentioning

confidence: 99%

Fabrication of mesoporous CuO/ZrO 2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)

Nanda

Pradhan

Parida

2017

Chemical Engineering Journal

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h i g h l i g h t sMesoporous ZrO 2 -MCM-41synthesized by in situ incorporation process. CuO@ZM-41 synthesized by modification of CuO onto the ZrO 2 -MCM-41. CuO@ZM-41nacomposite shows semiconductor behavior and mesoporosity. High surface area, lower e À and h + recombination are enhancing the photo-reduction. g r a p h i c a l a b s t r a c tMesoporous nanocomposite (CuO@ZM-41) is synthesized by incorporating mesoporous ZrO 2 (Z) into MCM-41 (M-41) framework followed by loading of CuO by wetness impregnation method. The synergism between CuO and the support material mesoporous ZM-41 and efficient light absorption on the surface of the composite is the key factor for the reduction Cr 6+ to Cr 3+ within 30 min time. a b s t r a c tMesoporous nanocomposites of CuO/ZrO 2 -MCM-41 (CuO@ZM-41) was designed by incorporating mesoporous ZrO 2 (Z) into the high surface area MCM-41 (M-41) framework followed by loading CuO by wetness impregnation method keeping Si/Zr ratio 10. The nanocomposites were studied under PXRD, N 2 sorption, DRS spectra, FTIR, XPS, NMR, HRTEM and PL to evaluate structural, morphological, optical properties and also the mesoporosity nature of the samples. The photo-reduction of Cr 6+ was performed over CuO@ZM-41 by varying pH, substrate concentration, and irradiation time and catalyst dose. Among all the catalysts, 2 CuO@ZM-41 was found to be efficient photocatalyst for the photo-reduction of Cr 6+ . Nearly 100% reduction of Cr 6+ has been achieved by 2 CuO@ZM-41 within 30 min. Intra-particle mesoporosity, high surface area, presence of CuO nanorods and electron transfer properties are the key factors for enhancing the photo-reduction activity of 2CuO@ZM-41.

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Physico-chemical and catalytic properties of Zr- and Cu–Zr ion-exchanged H-MCM-41

Cited by 10 publications

References 36 publications

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

Radioisotopic tracing of methanol transformation using 11C-labelled methanol over copper ion-exchanged H-ZSM-5, H-Beta and H-MCM-41

Fabrication of mesoporous CuO/ZrO 2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)

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