Investigation into the Enhanced Catalytic Oxidation of o-Xylene over MOF-Derived Co3O4 with Different Shapes: The Role of Surface Twofold-Coordinate Lattice Oxygen (O2f)

ACS Catalysis ◽  
2021 ◽  
pp. 6614-6625
Author(s):  
Ying Ma ◽  
Lian Wang ◽  
Jinzhu Ma ◽  
Honghong Wang ◽  
Changbin Zhang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Lattice Oxygen ◽  
Different Shapes

scholarly journals Role of CO2 During Oxidative Dehydrogenation of Propane Over Bulk and Activated-Carbon Supported Cerium and Vanadium Based Catalysts

2021 ◽  
Author(s):  
Petar Djinović ◽  
Janez Zavašnik ◽  
Janvit Teržan ◽  
Ivan Jerman
Keyword(s):  
Catalytic Activity ◽  
Activated Carbon ◽  
Oxidative Dehydrogenation ◽  
Active Phase ◽  
Lattice Oxygen ◽  
Chemisorbed Oxygen ◽  
Catalytically Active ◽  
Temperature Programmed ◽  
Propane Cracking

AbstractCeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested in propane oxidative dehydrogenation using CO2. Complete oxidation of propane to CO and CO2 is favoured by lattice oxygen of CeO2. The temperature programmed experiments show the ~ 4 nm AC supported CeO2 crystallites become more susceptible to reduction by propane, but less prone to re-oxidation with CO2 compared to bulk CeO2. Catalytic activity of CeVO4/AC catalysts requires a 1–2 nm amorphous CeVO4 layer. During reaction, the amorphous CeVO4 layer crystallises and several atomic layers of carbon cover the CeVO4 surface, resulting in deactivation. During reaction, V2O5 is irreversibly reduced to V2O3. The lattice oxygen in bulk V2O5 favours catalytic activity and propene selectivity. Bulk V2O3 promotes only propane cracking with no propene selectivity. In VOx/AC materials, vanadium carbide is the catalytically active phase. Propane dehydrogenation over VC proceeds via chemisorbed oxygen species originating from the dissociated CO2. Graphic Abstract

Insights into the synergistic role of metal–lattice oxygen site pairs in four-centered C–H bond activation of methane: the case of CuO

2016 ◽  
Vol 6 (11) ◽  
pp. 3984-3996 ◽  
Author(s):  
Jithin John Varghese ◽  
Quang Thang Trinh ◽  
Samir H. Mushrif
Keyword(s):  
Activation Energy ◽  
Copper Oxide ◽  
Bond Activation ◽  
Lattice Oxygen ◽  
Oxide Surfaces ◽  
Energy Barriers ◽  
Metal Lattice ◽  
Oxygen Site ◽  
Site Pair

Of the three mechanisms for activation of methane on copper and copper oxide surfaces, the under-coordinated Cu–O site pair mediated mechanism on CuO surfaces has the lowest activation energy barriers.

Effect of size and shape of nanofillers on electrostatic and thermal behavior of epoxy-based composites

2021 ◽  
pp. 096739112110324
Author(s):  
Mihir N Velani ◽  
Ritesh R Patel
Keyword(s):  
Thermal Properties ◽  
Breakdown Strength ◽  
Electrical Power ◽  
Filler Loading ◽  
Filler Concentration ◽  
Computational Technique ◽  
Electrical Power System ◽  
Potential Applications ◽  
Different Shapes

The role of nanodielectrics in the electrical power system is becoming crucial owing to its superior properties and potential applications in the field. Yet, the materials face limited breakdown strength and thermal properties. Further, the nanodielectrics have not found a comprehensive commercial platform because of the costly manufacturing process, and characterization and testing facilities. Therefore, to reduce the involved cost, in this work, an FE (finite element) based computational technique has been implemented to visualize the effect of shape, size, and filler concentration under the application of high voltage (HV). The epoxy-based nanodielectrics have been modeled incorporating a range of different shapes and size nanofillers—Al2O3, BN, BeO, SiO2, and TiO2. The paper discusses the 2D-analysis of the modeled nanodielectric in the steady-state electrostatic fields and thermal domains. It shows the insights of the nanofillers’ choice to ensure a perfect blend of electrical and thermal properties. The epoxy with square-shaped BeO fillers showed a rise in the electric field of nearly 1.5 times than unfilled neat epoxy, which indicates a significant surge in thermal conductivity at specific filler loading.

Role of Hydroxyl Groups in Low-Temperature CO Catalytic Oxidation over Zn4Si2O7(OH)2 Nanowire-Supported Gold Nanoparticles

2018 ◽  
Vol 122 (44) ◽  
pp. 25456-25466 ◽  
Author(s):  
Jing-Jing Li ◽  
Bao-Lin Zhu ◽  
Gui-Chang Wang ◽  
Zun-Feng Liu ◽  
Wei-Ping Huang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Low Temperature ◽  
Catalytic Oxidation ◽  
Hydroxyl Groups ◽  
Co Catalytic Oxidation ◽  
Supported Gold Nanoparticles ◽  
Supported Gold
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