نتایج جستجو برای: silica supported catalysts

تعداد نتایج: 257434  

Journal: :Chemical communications 2010
Etienne Mazoyer Nicolas Merle Aimery de Mallmann Jean-Marie Basset Elise Berrier Laurent Delevoye Jean-François Paul Christopher P Nicholas Régis M Gauvin Mostafa Taoufik

A well-defined, silica-supported tungsten oxo alkyl species prepared by the surface organometallic chemistry approach displays high and sustained activity in propene metathesis. Remarkably, its catalytic performances outpace those of the parent imido derivative, underlining the importance of the oxo ligand in the design of robust catalysts.

Journal: :Chemical communications 2012
Yang Zhang Tong Ren

Pre-synthesized ruthenium dioxide nanoparticulates (RuO(2) NPs) with low level of aggregation were well dispersed in mesoporous silica SBA-15. As a catalyst for water oxidation, the supported RuO(2) NPs exhibit excellent catalytic activity and recyclability. The initial turnover frequency (TOF) is to date the highest among comparable RuO(2) catalysts.

2001
Jih-Mirn Jehng Israel E. Wachs

The current investigation demonstrates that it is possible to molecularly design supported niobium oxide catalysts with the assistance of molecular characterization methods such as Raman spectroscopy. The formation and location of the surface niobium oxide species are controlled by the surface hydroxyl chemistry, and the surface niobium oxide species are located in the outermost layer of the ca...

2013
Mohamad Hassan Amin James Tardio Suresh K. Bhargava

The activity of Ni supported on mesoporous SBA-15, MCM-41, KIT-6, and a sol-gel prepared Ni/γAl2O3, for catalysing methane dry reforming was investigated. The chemical and physical characteristics of the catalysts before and after catalytic testing were investigated using X-Ray diffraction, X-ray Photoemission Spectroscopy, Transmission Electron Microscopy, Scanning Electron Microscopy / Energy...

2011
Luis-Felipe Gutiérrez Safia Hamoudi Khaled Belkacemi

Mesoporous silica materials (MSM) with ordered and controllable porous structure, high surface area, pore volume and thermal stability are very suitable catalyst supports, because they provide high dispersion of metal nanoparticles and facilitate the access of the substrates to the active sites. Since the conventional wet-impregnation and deposition-precipitation methods are not appropriate for...

S. Rezayati S. Sajjadifar

A mild and green method has been developed for the preparation of coumarins derivatives through the one-pot reactions. In our study,various phenols and ethyl acetoacetate compound in which we used silica-supported boron sulfonic acid [SiO2/B(SO4H)3] as a new, highly efficient and tri-functional inorganic Brønsted acid catalyst were processed under solvent-free condition and thermal. The catalys...

Journal: :The Journal of organic chemistry 2002
Shlomo Antebi Prabhat Arya Leo E Manzer Howard Alper

Palladium complexes immobilized onto generation 0-3 PAMAM dendrimers supported on silica were used as catalysts for the carbonylation of iodobenzene in methanol to form methyl benzoate. High yields were obtained and the catalyst was recycled 4-5 times without significant loss of activity. The carbonylation reaction was found to be applicable to a variety of iodoarenes regardless of the nature o...

2015
Anisha Chakrabarti Israel E. Wachs

This perspective article critically reviews the catalysis literature on the nature of the surface CrOx sites present on SiO2 in different environments. The recent application of in situ spectroscopic techniques that directly monitor the surface chromia sites on silica in different environments has significantly improved our fundamental understanding of supported CrOx/SiO2 catalysts.

Journal: :Dalton transactions 2014
Phillip Malcho Eduardo J Garcia-Suarez Uffe Vie Mentzel Christian Engelbrekt Anders Riisager

Heterogeneous silica supported rhodium-phosphine complex catalysts are employed for the first time in the catalytic decarbonylation of aldehydes in continuous gas-phase. The reaction protocol is exemplified for the decarbonylation of p-tolualdehyde to toluene and further extended to other aromatic and aliphatic aldehydes achieving excellent results in terms of both conversion and selectivity.

Journal: :Chemical communications 2012
Wanjun Li Aiqin Wang Xiaofeng Yang Yanqiang Huang Tao Zhang

Au/SiO(2), which was prepared properly to have a high dispersion of gold nanoparticles, acts as an extremely active catalyst for the selective oxidation of a variety of silanes. It outperforms other reducible oxide supported gold catalysts thanks to the affinity of the silica support to the silane substrate.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید