A new class of activated mesoporous Al-MCM-41 layers was deposited on Fe-CrAl metallic foils in the presence of cationic surfactant cetyltrimethylammonium bromide under basic conditions by an in-situ hydrothermal meth...A new class of activated mesoporous Al-MCM-41 layers was deposited on Fe-CrAl metallic foils in the presence of cationic surfactant cetyltrimethylammonium bromide under basic conditions by an in-situ hydrothermal method. The characterization techniques including X-ray diffraction, nitrogen adsorption and transmission electron microscopy, as well as field-emission scanning electron microscopy were performed to investigate the pore structure and surface morphology of the Al-MCM-41 layers. The Al-MCM-41 materials are of amorphous structure but exhibit large BET surface area （up to 757.0 m2/g） and pore volume （up to 0.72 cm3/g）, as well as a mean pore diameter of 3 nm. The layers deposited on the FeCrAl foils are continuous despite with a few of holes on the surface.展开更多
VOSO4 immobilized within nanoreactors of Al-MCM-41 (VO2+/Al-MCM-41) was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, and chemical analysi...VOSO4 immobilized within nanoreactors of Al-MCM-41 (VO2+/Al-MCM-41) was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, and chemical analysis techniques. The prepared VO2+/Al-MCM-41 successfully catalyzes the oxidation of aryl alkyl sulfides and up to 99% conversion and 90% selectivity for the corresponding sulfoxides were obtained with H2O2 as oxidant in acetonitrile at room temperature in 30 min.展开更多
Al-MCM-48 molecular sieves (Si/Al molar ratios = 25, 50, 75, and 100) were synthesized hydrothermally using cetyltrimethyl-ammonium bromide as the structure directing template. The orderly arrangement of mesopores was...Al-MCM-48 molecular sieves (Si/Al molar ratios = 25, 50, 75, and 100) were synthesized hydrothermally using cetyltrimethyl-ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and transmission electron microscopy images. The catalytic performance of the materials was evaluated in the vapor phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with the increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol with 78% selectivity. The delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Although an ester was used as the alkylating agent, phenyl isopropyl ether was not formed in the reaction.展开更多
基金Funded by the National Natural Science Foundation of China (No.50502002)Scientific Research Common Program of Beijing Municipal Commission of Education (No. KM200610005016)Youth Foundation of Beijing University of Technology (No.00190)
文摘A new class of activated mesoporous Al-MCM-41 layers was deposited on Fe-CrAl metallic foils in the presence of cationic surfactant cetyltrimethylammonium bromide under basic conditions by an in-situ hydrothermal method. The characterization techniques including X-ray diffraction, nitrogen adsorption and transmission electron microscopy, as well as field-emission scanning electron microscopy were performed to investigate the pore structure and surface morphology of the Al-MCM-41 layers. The Al-MCM-41 materials are of amorphous structure but exhibit large BET surface area （up to 757.0 m2/g） and pore volume （up to 0.72 cm3/g）, as well as a mean pore diameter of 3 nm. The layers deposited on the FeCrAl foils are continuous despite with a few of holes on the surface.
基金Supported by the Research Council of the University of Alzahra, Iran
文摘VOSO4 immobilized within nanoreactors of Al-MCM-41 (VO2+/Al-MCM-41) was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, and chemical analysis techniques. The prepared VO2+/Al-MCM-41 successfully catalyzes the oxidation of aryl alkyl sulfides and up to 99% conversion and 90% selectivity for the corresponding sulfoxides were obtained with H2O2 as oxidant in acetonitrile at room temperature in 30 min.
基金the financial support from the Department of Science and Technology (Sanction No. SR/S1/PC-10/2009, Dated 28.10.2009)University Grants Commission (UGC), New Delhi for providing funds under special assistance - DRS programme and Department of Science and Technology, New Delhi, under FIST programme for equipment facilities in the Department
文摘Al-MCM-48 molecular sieves (Si/Al molar ratios = 25, 50, 75, and 100) were synthesized hydrothermally using cetyltrimethyl-ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and transmission electron microscopy images. The catalytic performance of the materials was evaluated in the vapor phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with the increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol with 78% selectivity. The delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Although an ester was used as the alkylating agent, phenyl isopropyl ether was not formed in the reaction.
