نتایج جستجو برای: vanadia loading

تعداد نتایج: 76752  

2005
C. Hess

The partial oxidation of methanol to formaldehyde was studied over highly dispersed vanadia supported on mesoporous silica SBA-15 (VOx/SBA-15). VOx/SBA-15 catalysts were prepared by a novel grafting/ion-exchange method and characterized using UV-VISand Raman spectroscopy. The resulting surface vanadium oxide species (0 – 2.3 V/nm), grafted on the inner pores of the SBA-15 silica matrix, consist...

2010
P. Gruene T. Wolfram K. Pelzer R. Schlögl A. Trunschke

A series of vanadia catalysts supported on the mesoporous silica SBA-15 are synthesized using an automated laboratory reactor. The catalysts contain from 0.6 up to 13.6V atoms/nm and are structurally characterized by various techniques (BET, XRD, SEM, TEM, Raman, IR, UV/Vis). Samples containing up to 3.1V/nm are structurally rather similar. They all contain a mixture of tetrahedral (VOx)n speci...

Journal: :iranian journal of catalysis 2014
yousef zeinaly seyed mehdi alavi

supported vanadia catalyst was successfully synthesized using wet impregnation of gamma-alumina to study propane oxidative dehydrogenation (pod). the prepared catalysts were characterized with xrd, bet, and tpr tests. in a broad temperature range (340 to 630°c), effects of vanadia loading (2.7, 5.4, and 9 wt%) and propane to oxygen ratio (3/1 to 1/3) were investigated on propane conversion as w...

1996
Michael D. Amiridis Israel E. Wachs Goutam Deo Jih-Mirn Jehng Soung Kim

Reactivity of V2O5 Catalysts for the Selective Catalytic Reduction of NO by NH3: Influence of Vanadia Loading, H2O, and SO2 Michael D. Amiridis,∗,1 Israel E. Wachs,† Goutam Deo,† Jih-Mirn Jehng,† and Du Soung Kim† ∗Research Division, W.R. Grace & Co.-Conn., Columbia, Maryland 21044; and †Zettlemoyer Center for Surface Studies and Department of Chemical Engineering, Lehigh University, Bethlehem,...

Seyed Mehdi Alavi, Yousef Zeinaly

Supported vanadia catalyst was successfully synthesized using wet impregnation of gamma-Alumina to study Propane Oxidative Dehydrogenation (POD). The prepared catalysts were characterized with XRD, BET, and TPR tests. In a broad temperature range (340 to 630°C), effects of vanadia loading (2.7, 5.4, and 9 wt%) and propane to oxygen ratio (3/1 to 1/3) were investigated on propane conversion as w...

Seyed Mehdi Alavi, Yousef Zeinaly

Supported vanadia catalyst was successfully synthesized using wet impregnation of gamma-Alumina to study Propane Oxidative Dehydrogenation (POD). The prepared catalysts were characterized with XRD, BET, and TPR tests. In a broad temperature range (340 to 630°C), effects of vanadia loading (2.7, 5.4, and 9 wt%) and propane to oxygen ratio (3/1 to 1/3) were investigated on propane conversion as w...

Journal: :Advanced Materials Science and Technology 2022

High-surface-area mesoporous CexZr1-xO2 materials synthesized through a surfactant-assisted approach of nanocrystalline particle assembly are utilized as promising support for VOx-based catalysts. The catalytic properties the resultant VOx/CexZr1-xO2 nanocatalysts evaluated by oxidative dehydrogenation propane using microreactor-GC system. It is indicated that catalyst particles ...

Journal: :Journal of the American Chemical Society 2010
Julie E Molinari Israel E Wachs

Recent debates over the active site structure of supported vanadia/silica catalysts have suggested the existence of a surface vanadium peroxo-oxo "umbrella" structure. This study definitively demonstrates with Raman and UV-vis spectroscopy that the surface vanadia peroxo-oxo umbrella-like structure is not present for both hydrated and dehydrated supported vanadia catalysts such as supported van...

Journal: :Physical chemistry chemical physics : PCCP 2008
Guido Mul Walter Wasylenko M Sameh Hamdy Heinz Frei

Vanadia was incorporated in the 3-D mesoporous material TUD-1 with a loading of 2% w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in ...

Journal: :Journal of the American Chemical Society 2010
Maria Veronica Ganduglia-Pirovano Cristina Popa Joachim Sauer Heather Abbott Alexander Uhl Martin Baron Dario Stacchiola Oleksandr Bondarchuk Shamil Shaikhutdinov Hans-Joachim Freund

The effect of the suppport on oxidative dehydrogenation activity for vanadia/ceria systems is examined for the oxidation of methanol to formaldehyde by use of well-defined VO(x)/CeO(2)(111) model catalysts. Temperature-programmed desorption at low vanadia loadings revealed reactivity at much lower temperature (370 K) as compared to pure ceria and vanadia on inert supports such as silica. Densit...

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