Active sites in modified copper catalysts for selective liquid phase dehydration of aqueous glycerol to acetol

RSC Advances ◽  
2013 ◽  
Vol 3 (37) ◽  
pp. 16499 ◽  
Author(s):  
Rasika B. Mane ◽  
Aritomo Yamaguchi ◽  
Atul Malawadkar ◽  
Masayuki Shirai ◽  
Chandrashekhar V. Rode
Keyword(s):  
Liquid Phase ◽  
Active Sites ◽  
Copper Catalysts

scholarly journals Solid-to-liquid phase transitions of sub-nanometer clusters enhance chemical transformation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan-Juan Sun ◽  
Jun Cheng
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Active Sites ◽  
Catalyst Activity ◽  
Ab Initio Molecular Dynamics ◽  
Free Energies ◽  
Elementary Reactions ◽  
Au Clusters ◽  
Calculate Temperature Dependence ◽  
Entropic Effects

AbstractUnderstanding the nature of active sites is crucial in heterogeneous catalysis, and dynamic changes of catalyst structures during reaction turnover have brought into focus the dynamic nature of active sites. However, much less is known on how the structural dynamics couples with elementary reactions. Here we report an anomalous decrease in reaction free energies and barriers on dynamical sub-nanometer Au clusters. We calculate temperature dependence of free energies using ab initio molecular dynamics, and find significant entropic effects due to solid-to-liquid phase transitions of the Au clusters induced by adsorption of different states along the reaction coordinate. This finding demonstrates that catalyst dynamics can play an important role in catalyst activity.

Silica-supported Cu–Pt bimetallic catalysts for liquid-phase diethyl oxalate hydrogenation

2018 ◽  
Vol 96 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Wei Long ◽  
Pingle Liu ◽  
Yang Lv ◽  
Wei Xiong ◽  
Fang Hao ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Catalysts ◽  
Nitrogen Adsorption ◽  
Hydrogen Uptake ◽  
Copper Catalysts ◽  
Catalytic Performance ◽  
Diethyl Oxalate ◽  
Hydrogen Chemisorption ◽  
Adsorption Desorption

Silica-supported copper catalysts were prepared by different methods, and Cu/SiO2 prepared by the urea-assisted gel method was modified with co-catalyst platinum to obtain Cu-Pt/SiO2 bimetallic catalysts. The prepared catalysts were characterized by nitrogen adsorption–desorption, XRD, TEM, hydrogen chemisorption, ammonia gas chemisorption, and X-ray photoelectron spectroscopy. The characterization results show that the modification of platinum is helpful to the reduction and dispersion of copper species, which increase the hydrogen uptake quantity and metal surface area. The 30%Cu–3.0%Pt/SiO2-6 presents the best catalytic performance in liquid-phase diethyl oxalate hydrogenation; it gives 77.32% conversion of diethyl oxalate and 94.37% selectivity to the main products under 473 K and 3.0 MPa for 4 h. A possible reaction route was also proposed.

Active sites for the liquid-phase beckmann rearrangement of cyclohexanone, acetophenone and cyclododecanone oximes, catalyzed by beta zeolites

1998 ◽  
Vol 177 (2) ◽  
pp. 267-272 ◽  
Author(s):  
M CAMBLOR ◽  
A CORMA ◽  
H GARCIA ◽  
V SEMMERHERLEDAN ◽  
S VALENCIA
Keyword(s):  
Liquid Phase ◽  
Active Sites ◽  
Beckmann Rearrangement ◽  
Beta Zeolites

Liquid-Phase Selective Hydrogenation of Nitrobenzene over Ultrasonic-Assisted Ni-Mo-P Amorphous Catalyst

2012 ◽  
Vol 550-553 ◽  
pp. 420-423 ◽  
Author(s):  
Qian Wen Dai ◽  
Zi Li Liu ◽  
Cui Xia Xu ◽  
Qi Gang Xie ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Liquid Phase ◽  
Selective Hydrogenation ◽  
Active Sites ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Catalytic Performance ◽  
Chemical Reduction Method ◽  
Ultrasonic Assisted ◽  
Optimal Reaction

The Ni-Mo-P amorphous catalysts were prepared by chemical reduction method under different sonication conditions. The catalytic performance of the prepared catalysts in selective hydrogenation of nitrobenzene(NB) to aniline(AN) were characterized by XRD, BET, N2-adsorption, H2-TPR and H2-TPD. The results show that the introduction of ultrasonic can improve the dispersion of the active sites in the catalyst, the particle size of the catalyst is also smaller than the regular prepared Ni-Mo-P amorphous catalyst. And the influences of the sonication power and time on the catalysts were discussed and compared. The optimal sonication condition is 70 W within 25 min, its optimal reaction time is 150 min.

scholarly journals Rücktitelbild: Stabilization of Copper Catalysts for Liquid-Phase Reactions by Atomic Layer Deposition (Angew. Chem. 51/2013)

2013 ◽  
Vol 125 (51) ◽  
pp. 14068-14068 ◽  
Author(s):  
Brandon J. O'Neill ◽  
David H. K. Jackson ◽  
Anthony J. Crisci ◽  
Carrie A. Farberow ◽  
Fengyuan Shi ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Copper Catalysts ◽  
Layer Deposition

scholarly journals Back Cover: Stabilization of Copper Catalysts for Liquid-Phase Reactions by Atomic Layer Deposition (Angew. Chem. Int. Ed. 51/2013)

2013 ◽  
Vol 52 (51) ◽  
pp. 13824-13824
Author(s):  
Brandon J. O'Neill ◽  
David H. K. Jackson ◽  
Anthony J. Crisci ◽  
Carrie A. Farberow ◽  
Fengyuan Shi ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Copper Catalysts ◽  
Back Cover ◽  
Layer Deposition
Sign in / Sign up

Export Citation Format

Share Document