Immobilized Polyoxomolybdate Nanoclusters on Functionalized SBA-15: Green Access to Efficient and Recyclable Nanocatalyst for the Epoxidation of Alkenes

2019-05-24
Bagherzadeh, Mojtaba
Hosseini, Hadighehsadat
AKBAYRAK, SERDAR
Özkar, Saim
A heterogeneous nanocatalyst containing polyoxomolybdate immobilized on the internal surface of amino-functionalized SBA-15 pores was prepared and fully characterized by several analytical techniques. The textural property of supported material was found to retain important mesoporous features, compatible with its potential use as heterogeneous catalysts. The catalyst SBA-15-NH3+center dot{Mo-36}(-)shows excellent catalytic activity for the epoxidation of alkenes as compared to POM, which is attributed to the large specific surface area and highly ordered pore structure of SBA-15, allowing for easy access of reactants to the active sites and removal of products. The prepared catalyst has high recyclability performance without obvious loss of activity after six runs of epoxidation.
CHEMISTRYSELECT

Suggestions

Synergistic effect of boron containing substances on flame retardancy and thermal stability of intumescent polypropylene composites
Yılmaz, Ayşen; BAYRAMLI, ERDAL (2010-12-01)
The synergistic effect of four different boron containing substances, zinc borate (ZnB), borophosphate (BPO4), boron silicon containing preceramic oligomer (BSi) and lanthanum borate (LaB), were studied to improve the flame retardancy of a polypropylene (PP) intumescent system composed of ammonium polyphosphate (APP) and pentaerythritol (PER). The flame retardancy of PP composites was investigated by limiting oxygen index (LOI). UL-94 standard, thermogravimetric analysis (TGA) and cone calorimeter tests. Th...
Hydrothermal and microwave synthesis of boron phosphate, BPO(4)
Baykal, Altan; Toprak, M; Kniep, R (2001-01-01)
BPO4 was previously synthesized by the solid state reactions of (NH4)(2)HPO4 and B2O3 at 1000 degreesC and was characterized by X-ray powder diffraction and IR methods. We have now succeeded in preparing BPO4 from H3BO3 and P2O5 using hydrothermal synthesis by heating at 160 degreesC for 2 days and obtained a single phase product. We observed that a microwave-assisted synthesis takes only 3 to 5 minutes to transform a solid mixture of (NH4)(2)B4O7. 4H(2)O, and solid H3PO4 Or B2O3 + P2O5 into the crystalline...
Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
Doğan, Özdemir (2015-12-15)
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphonate POAP-A Lewis bases formed the aldol products in up to 75% yield and with 65% ee.
Flame retardancy effects of zinc borate and nanoclay in ABS, and boron compounds in PET
Özkaraca, Ayşe Çağıl; Kaynak, Cevdet; Department of Metallurgical and Materials Engineering (2011)
In this thesis there were two main purposes, the first one being to investigate effects of zinc borate (ZB) on the flammability behavior of ABS when used with and without a traditional brominated flame retardant (BFR) / antimony trioxide (AO) system. The second purpose was to investigate contribution of nanoclays (NC) to the flame retardancy performance of the same traditional BFR compound with various combinations of AO and ZB again in ABS matrix. For these purposes, materials were melt compounded by using...
Sulfated zirconia in SBA-15 structures with strong Bronsted acidity as observed by H-1 MAS NMR spectroscopy
Yılmaz, Ayşen; Yılmaz, Aysun; Üner, Deniz (2007-05-01)
In order to prepare high surface area highly acidic catalysts, different weight loadings of ZrO2 were incorporated in the SBA-15 structures which are subsequently sulfated by treating in 0.25 M H2SO4. The catalysts were characterized by means of TEM, XRD, N-2 adsorption, and H-1 MAS NMR. Bronsted type acidities of sulfated zirconia included SBA-15 materials were identified by a sharp H-1 MAS NMR line at 10.6 ppm. The highest acidity was obtained in the 25 mol% ZrO2 included SBA-15 catalyst with a BET surfac...
Citation Formats
M. Bagherzadeh, H. Hosseini, S. AKBAYRAK, and S. Özkar, “Immobilized Polyoxomolybdate Nanoclusters on Functionalized SBA-15: Green Access to Efficient and Recyclable Nanocatalyst for the Epoxidation of Alkenes,” CHEMISTRYSELECT, pp. 5911–5917, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38358.