نتایج جستجو برای: mnna2wo4 sio2 catalyst

تعداد نتایج: 57042  

1999
Israel E. Wachs

In situ Raman spectroscopy is rapidly becoming a very popular catalyst characterization method because Raman cells are being designed that can combine in situ molecular characterization studies with simultaneous fundamental quantitative kinetic studies. The dynamic nature of catalyst surfaces requires that both sets of information be obtained for a complete fundamental understanding of catalyti...

In this work, ZnO/SiO2 nanoparticles were prepared using sol-gel method, and platinum particles were loaded on ZnO/SiO2 nanoparticles by photoreductive method. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The XRD patterns showed that the zinc oxide samples have a wurtzite structure (hexagonal phase...

2013
Hossein Naeimi Zahra Sadat Nazifi

ABSTRACT The functionalization of silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2) using chlorosulfonic acid were afforded sulfonic acid-functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2-SO3H) that can be applied as an organic-inorganic hybrid heterogeneous catalyst. The used Fe3O4 magnetic nanoparticles are 18-30 nm sized that was rapidly functionalized and can be used as catalyst...

Journal: :iranian journal of catalysis 2013
hamid aliyan razieh fazaeli nafiseh tajsaeed

a new type of magnetically-recoverable catalyst was synthesized by the immobilization of h3pw12o40 on the surface of silica-encapsulated -fe2o3 nanoparticles. a series of novel 1,3,5-triaryl pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in the presence of the -fe2o3@sio2-pw12nanoparticles,  in high yields. the structures of compounds obtained were...

Journal: :journal of advanced medical sciences and applied technologies 0
leila zamani b. f. mirjalili department of chemistry, college of science, yazd university, yazd,po box 89195-741, i. r. iran

this research proposes an efficient and easy procedure for the preparation of amides or nitriles from aldehydes. such materials were prepared via one-pot three component condensation reaction of various aldehydes in the presence of nano-ticl4.sio2 as a catalyst under thermal conditions. all reactions proceeded in high yields and in a moderately short reaction time. meanwhile, oximes were obtain...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2011
ghodsi mohammadi ziarani alireza badiei masoomeh azizi peshman zarabadi

3,4-ِdihydropyrano[c]chromene derivatives were synthesized using sulfonic acid functionalized silica (sio2-pr-so3h) as a highly efficient heterogenous solid acid catalyst via one-pot three-component condensation of aromatic aldehydes with malononitrile and 4-hydroxycoumarin in excellent yields.

Nano-silica supported boron trifluoride (BF3.SiO2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. So, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes  in good to excellent yields. The reactions were carried out at room temperature under solven...

2009
Rong Xiang Erik Einarsson Hiroto Okabe Shohei Chiashi Junichiro Shiomi Shigeo Maruyama

Here we show that the conventional concept of using SiO2 patterned Si substrates to selectively grow 3D carbon nanotube structures can also be applied to a dip-coating method. High-quality vertically aligned single-walled carbon nanotube (SWNT) patterns can be easily obtained by this protocol. Apart from the sintering of catalyst into Si at high temperature, the difference in surface wettabilit...

2011
Qiaohong Zhang Chen Chen Min Wang Jiaying Cai Jie Xu Chungu Xia

Highly dispersed cobalt-silicon mixed oxide [Co-SiO2] nanosphere was successfully prepared with a modified reverse-phase microemulsion method. This material was characterized in detail by X-ray diffraction, transmission electron microscopy, Fourier transform infrared, ultraviolet-visible diffuse reflectance spectra, X-ray absorption spectroscopy near-edge structure, and N2 adsorption-desorption...

Journal: :IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) 2023

Hydrocracking of crude palm oil (CPO) to produce biofuels was conducted over zirconium nitride supported on SiO2 (SiO2/ZrN) catalyst. SiO2/ZrN prepared by nitriding the SiO2/Zr at 600 C for 3 hrs under NH3 gas cylindrical reactor. exhibited a surface acidity 0.7132 mmol pyridine g‒1 with area 96 m2 g‒1, forming predominant mesopores EDS- mapping analysis showed that ZrN species highly distribu...

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