Phenol hydrodeoxygenation: effect of support and Re promoter on the reactivity of Co catalysts

2016 ◽  
Vol 6 (19) ◽  
pp. 7289-7306 ◽  
Author(s):  
I. T. Ghampson ◽  
C. Sepúlveda ◽  
A. B. Dongil ◽  
G. Pecchi ◽  
R. García ◽  
...  
Keyword(s):  
Co Catalysts ◽  
Oxide Support ◽  
Silica Alumina ◽  
Effect Of Support ◽  
Autoclave Reactor

In this work, the reactivity of supported Co catalysts as a function of the oxide support (alumina, silica-alumina, zirconia and titania) and Re promoter for the hydrodeoxygenation of phenol at 300 °C and 3 MPa H2 using a batch autoclave reactor was investigated.

scholarly journals Effect of Metal Oxide–Support Interactions on Ethylene Oligomerization over Nickel Oxide/Silica–Alumina Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 933
Author(s):  
Ji Sun Yoon ◽  
Min Bum Park ◽  
Youngmin Kim ◽  
Dong Won Hwang ◽  
Ho-Jeong Chae
Keyword(s):  
Catalytic Activity ◽  
Metal Oxide ◽  
Nickel Oxide ◽  
Ethylene Oligomerization ◽  
Nickel Aluminate ◽  
X Ray ◽  
Oxide Support ◽  
Metal Oxide Support ◽  
Silica Alumina ◽  
Temperature Programmed

We investigated the interactions between nickel oxide and silica–alumina supports, which were applied to the catalytic oligomerization of ethylene by powder X-ray diffraction, UV diffuse reflectance spectroscopy, H2 temperature-programmed reduction, and X-ray photoelectron spectroscopy. The catalytic activity was also correlated with the acidity of catalysts determined by NH3 temperature-programmed desorption and pyridine FT-IR spectroscopy. Although all the catalysts had similar Ni contents, their catalytic performances were strongly influenced by the strength of the metal oxide–support interaction. Strong interaction promoted the formation of nickel aluminate on the catalyst surface, and resulted in low catalytic activity due to reducing the amount of nickel oxide active sites. However, weak interaction favored the aggregation of nickel oxide species into larger particles, and thus resulted in low ethylene conversion and selectivity to oligomers. Eventually, the optimal activity was realized at the medium interaction strength, preserving a high amount of both active nickel oxides and acid sites.

scholarly journals Hydrotreatment of lignin dimers over NiMoS-USY: effect of silica/alumina ratio

2021 ◽  
Author(s):  
Muhammad Abdus Salam ◽  
You Wayne Cheah ◽  
Phuoc Hoang Ho ◽  
Louise Olsson ◽  
Derek Creaser
Keyword(s):  
Y Zeolites ◽  
Silica Alumina ◽  
Silica Alumina Ratio ◽  
Autoclave Reactor

Sulfides of NiMo over a series of commercial ultra-stable Y zeolites were studied in an autoclave reactor to elucidate the effect of Silica/Alumina ratio (SAR=12, 30, and 80) on the...

Effect of Support on Metathesis ofn-Decane: Drastic Improvement in Alkane Metathesis with WMe5Linked to Silica-Alumina

2015 ◽  
Vol 21 (16) ◽  
pp. 6100-6106 ◽  
Author(s):  
Manoja K. Samantaray ◽  
Raju Dey ◽  
Edy Abou-Hamad ◽  
Ali Hamieh ◽  
Jean-Marie Basset
Keyword(s):  
Alkane Metathesis ◽  
Silica Alumina ◽  
Effect Of Support

scholarly journals Effect of support on catalytic cracking of bio-oil over Ni/silica-alumina

2017 ◽  
Author(s):  
Sunarno ◽  
Syamsu Herman ◽  
Rochmadi ◽  
Panut Mulyono ◽  
Arief Budiman
Keyword(s):  
Catalytic Cracking ◽  
Bio Oil ◽  
Silica Alumina ◽  
Effect Of Support

scholarly journals Effect of support on hydro-metathesis of propene: A comparative study of W(CH3)6 anchored to silica vs. silica-alumina

2018 ◽  
Vol 863 ◽  
pp. 102-108 ◽  
Author(s):  
Mykyta Tretiakov ◽  
Manoja K. Samantaray ◽  
Aya Saidi ◽  
Jean-Marie Basset
Keyword(s):  
Comparative Study ◽  
Silica Alumina ◽  
Effect Of Support

Fluidized Catalytic Cracking Catalyst Microstructure as Determined by A Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 302-303
Author(s):  
J.K. Lampert ◽  
G.S. Koermer ◽  
J.M. Macaoy ◽  
J.M. Chabala ◽  
R. Levi-Setti
Keyword(s):  
Catalytic Cracking ◽  
Secondary Ion Mass Spectrometry ◽  
Fuel Oil ◽  
Ion Microprobe ◽  
Fluidized Catalytic Cracking ◽  
Ion Probe ◽  
Silica Alumina ◽  
Resolution Imaging ◽  
The University ◽  
High Spatial Resolution Imaging

We have used high spatial resolution imaging secondary ion mass spectrometry (SIMS) to differentiate mineralogical phases and to investigate chemical segregations in fluidized catalytic cracking (FCC) catalyst particles. The oil industry relies on heterogeneous catalysis using these catalysts to convert heavy hydrocarbon fractions into high quality gasoline and fuel oil components. Catalyst performance is strongly influenced by catalyst microstructure and composition, with different chemical reactions occurring at specific types of sites within the particle. The zeolitic portions of the particle, where the majority of the oil conversion occurs, can be clearly distinguished from the surrounding silica-alumina matrix in analytical SIMS images.The University of Chicago scanning ion microprobe (SIM) employed in this study has been described previously. For these analyses, the instrument was operated with a 40 keV, 10 pA Ga+ primary ion probe focused to a 30 nm FWHM spot. Elemental SIMS maps were obtained from 10×10 μm2 areas in times not exceeding 524s.

Electron Holographic Nano-Characterization of Gold Catalyst at Interface

2002 ◽  
Vol 727 ◽  
Author(s):  
S. Ichikawa ◽  
T. Akita ◽  
M. Okumura ◽  
M. Haruta ◽  
K. Tanaka
Keyword(s):  
Contact Angle ◽  
Titanium Oxide ◽  
Gold Catalyst ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Electron Holography ◽  
Gold Particles ◽  
Oxide Support ◽  
The Mean ◽  
A Charge

AbstractThe catalytic properties of nanostructured gold catalyst are known to depend on the size of the gold particles and to be activated when the size decreases to a few nanometers. We investigated the size dependence of the three-dimensional nanostructure on the mean inner potential of gold catalysts supported on titanium oxide using electron holography and high-resolution electron microscopy (HREM). The contact angle of the gold particles on the titanium oxide tended to be over 90° for gold particles with a size of over 5 nm, and below 90° for a size of below 2 nm. This decreasing change in the contact angle (morphology) acts to increase the perimeter and hence the area of the interface between the gold and titanium oxide support, which is considered to be an active site for CO oxidation. The mean inner potential of the gold particles also changed as their size decreased. The value of the inner potential of gold, which is approximately 25 V in bulk state, rose to over 40 V when the size of the gold particles was less than 2 nm. This phenomenon indicates the existence of a charge transfer at the interface between gold and titanium oxide. The 3-D structure change and the inner potential change should be attributed to the specific electronic structure at the interface, owing to both the “nano size effect” and the “hetero-interface effect.”

Bimetallic Radical Redox-Relay Catalysis for the Isomerization of Epoxides to Allylic Alcohols

2019 ◽  
Author(s):  
Ke-Yin Ye ◽  
Terry McCallum ◽  
Song Lin
Keyword(s):  
Ring Opening ◽  
High Reactivity ◽  
Hydrogen Atom Transfer ◽  
Organic Radicals ◽  
Epoxide Ring ◽  
Allylic Alcohols ◽  
Epoxide Ring Opening ◽  
Bond Forming ◽  
Co Catalysts ◽  
The Rich

Organic radicals are generally short-lived intermediates with exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely bimetallic radical redox-relay, in the regio- and stereoselective rearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti and Co complexes and merges reductive epoxide ring opening (initiation) with hydrogen atom transfer (termination). Critically, upon effecting key bond-forming and -breaking events, Ti and Co catalysts undergo proton-transfer/electron-transfer with one another to achieve turnover, thus constituting a truly synergistic dual catalytic system.<br>

Effect of support plates on the micro-drilled hole form quality in CFRP laminates

2019 ◽  
Vol 61 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Ahmet Dogrusadik ◽  
Aykut Kentli
Keyword(s):  
Cfrp Laminates ◽  
Form Quality ◽  
Effect Of Support
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