Application of 3-D Hierarchically Porous Silver, Cobalt Oxide and Zinc Oxide Monoliths to Chromatographic Separations

2012 ◽  
Vol 1389 ◽  
Author(s):  
Franchessa M. Sayler ◽  
Amy Grano ◽  
Susan Wiedmer ◽  
Jan-Henrik Smått ◽  
Martin G. Bakker
Keyword(s):  
Zinc Oxide ◽  
Cobalt Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Chromatographic Separations ◽  
Hierarchically Porous ◽  
Molecular Separation ◽  
Porous Silver ◽  
Liquid Chromatographic

ABSTRACTHierarchically porous silica monoliths were introduced into liquid phase chromatography at the beginning of the last decade. The high surface area, high void volume and bicontinuous nature of the porosity of the materials are significant advantages over existing chromatographic supports and have resulted in rapid acceptance of these materials into the chromatography market.We report here on the synthesis of 3-D porous silver, cobalt oxide and zinc oxide monoliths, their materials characterization, fabrication as liquid chromatographic columns and initial chromatographic characterization. The, as prepared, columns gave very low back pressure, consistent with the bicontinuous nature of the columns. Cobalt oxide and zinc oxide both demonstrated retention of a number of nitrogen heterocycles, providing the basis for molecular separation.

X-ray and FIB Tomography of Extremely High Surface Area Nanostructured Hollow Fiber Membranes

2012 ◽  
Vol 1421 ◽  
Author(s):  
Amy J. Grano ◽  
Franchessa M. Sayler ◽  
Amber Genau ◽  
Keana L. Graves ◽  
Brian M. Patterson ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Porous Metal ◽  
Sample Volume ◽  
Ionic Conductors ◽  
Hierarchically Porous ◽  
X Ray ◽  
Synthesis Conditions ◽  
Wide Range

ABSTRACTHierarchically porous materials are of interest in a wide range of applications. If the materials are electronic, or ionic conductors, such materials are of interest as electrodes for use in fuel cells. Using hierarchically porous silica as templates, we have demonstrated the formation of hierarchically porous metal and metal oxide structures. Through the control of the synthesis conditions, we have produced partial replicas ca. 1 cubic centimeter in volume, in which two macroporous networks are separated by a nanoporous membrane. The macroporous network in the silica template is known to be bicontinuous. Our underlying model predicts that the second, induced, macroporous network should be similarly bicontinuous.Micrometer resolution X-ray tomography of the whole sample confirms that the synthesis produces one bicontinuous macroporous network, and is consistent with the existence of a second set of macropores. Preliminary experiments were carried out using FIB/SEM serial tomography to image the second macropore network, however, the length scale of the structures is such that this approach it is unable to firmly establish that the second macropore network is bicontinuous throughout the entire sample volume.

scholarly journals Effects of Annealing Temperature on the Oxygen Evolution Reaction Activity of Copper–Cobalt Oxide Nanosheets

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 657
Author(s):  
Geul Han Kim ◽  
Yoo Sei Park ◽  
Juchan Yang ◽  
Myeong Je Jang ◽  
Jaehoon Jeong ◽  
...  
Keyword(s):  
High Activity ◽  
Cobalt Oxide ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Cobalt Hydroxide ◽  
Ni Foam ◽  
Electron Conduction

Developing high performance, highly stable, and low-cost electrodes for the oxygen evolution reaction (OER) is challenging in water electrolysis technology. However, Ir- and Ru-based OER catalysts with high OER efficiency are difficult to commercialize as precious metal-based catalysts. Therefore, the study of OER catalysts, which are replaced by non-precious metals and have high activity and stability, are necessary. In this study, a copper–cobalt oxide nanosheet (CCO) electrode was synthesized by the electrodeposition of copper–cobalt hydroxide (CCOH) on Ni foam followed by annealing. The CCOH was annealed at various temperatures, and the structure changed to that of CCO at temperatures above 250 °C. In addition, it was observed that the nanosheets agglomerated when annealed at 300 °C. The CCO electrode annealed at 250 °C had a high surface area and efficient electron conduction pathways as a result of the direct growth on the Ni foam. Thus, the prepared CCO electrode exhibited enhanced OER activity (1.6 V at 261 mA/cm2) compared to those of CCOH (1.6 V at 144 mA/cm2), Co3O4 (1.6 V at 39 mA/cm2), and commercial IrO2 (1.6 V at 14 mA/cm2) electrodes. The optimized catalyst also showed high activity and stability under high pH conditions, demonstrating its potential as a low cost, highly efficient OER electrode material.

scholarly journals A Brief Overview of Recent Progress in Porous Silica as Catalyst Supports

2021 ◽  
Vol 5 (3) ◽  
pp. 75
Author(s):  
Preeti S. Shinde ◽  
Pradnya S. Suryawanshi ◽  
Kanchan K. Patil ◽  
Vedika M. Belekar ◽  
Sandeep A. Sankpal ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Textural Properties ◽  
Silica Particles ◽  
Catalyst Supports ◽  
Silica Supports ◽  
Low Degree ◽  
Transfer Properties

Porous silica particles have shown applications in various technological fields including their use as catalyst supports in heterogeneous catalysis. The mesoporous silica particles have ordered porosity, high surface area, and good chemical stability. These interesting structural or textural properties make porous silica an attractive material for use as catalyst supports in various heterogeneous catalysis reactions. The colloidal nature of the porous silica particles is highly useful in catalytic applications as it guarantees better mass transfer properties and uniform distribution of the various metal or metal oxide nanocatalysts in solution. The catalysts show high activity, low degree of metal leaching, and ease in recycling when supported or immobilized on porous silica-based materials. In this overview, we have pointed out the importance of porous silica as catalyst supports. A variety of chemical reactions catalyzed by different catalysts loaded or embedded in porous silica supports are studied. The latest reports from the literature about the use of porous silica-based materials as catalyst supports are listed and analyzed. The new and continued trends are discussed with examples.

scholarly journals Ethylene Adsorption Using Cobalt Oxide-Loaded Polymer-Derived Nanoporous Carbon and Its Application to Extend Shelf Life of Fruit

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1507 ◽  
Author(s):  
Imam Prasetyo ◽  
Nur Indah Fajar Mukti ◽  
Teguh Ariyanto
Keyword(s):  
Shelf Life ◽  
Cobalt Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Nanoporous Carbon ◽  
Carbon Surface ◽  
Calcination Process ◽  
Weight Percentage ◽  
Ethylene Adsorption ◽  
Ethylene Removal

Suppressing the amount of ethylene during storage has been of interest as a method to enhance shelf life of fruit. In this work, ethylene removal by adsorption using cobalt oxide-impregnated nanoporous carbon has been studied. Nanoporous carbon with a high surface area up to 2400 m2 g−1 was prepared by carbonization process biomass and synthetic polymer at 850 °C. Dispersion of cobalt oxide on porous carbon surface was carried out by an incipient wetness procedure followed by calcination process at 200 °C. Ethylene adsorption test was performed using a volumetric method in an ultrahigh vacuum rig constructed by Swagelok VCR® fittings. The results showed that the cobalt oxide/carbon system had significant ethylene adsorption capacity. Ethylene uptake increases with the increasing cobalt oxide loading on the carbon. The highest ethylene capacity of 16 mol kg−1 adsorbent was obtained by using 30 wt.% (weight percentage) of cobalt oxide dispersed in polymer-derived carbon. In closed storage, the ratio of 15 g adsorbent/kg fruit may extend the storage life up to 12 d, higher than that without adsorbent (3 d). Therefore, the results demonstrate the great potential use of cobalt oxide-impregnated nanoporous carbon as an adsorbent for ethylene removal during storage of fruit.

Catalytic conversion of methyl oleate to hydrocarbons: impact of cobalt oxide species integration in SiO2–Al2O3

2020 ◽  
Vol 4 (7) ◽  
pp. 3308-3317
Author(s):  
R. Krishnapriya ◽  
Unnati Gupta ◽  
Vineet K. Soni ◽  
Rakesh K. Sharma
Keyword(s):  
Methyl Oleate ◽  
Surface Area ◽  
Cobalt Oxide ◽  
Catalytic System ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Conversion ◽  
High Quality ◽  
Selective Deoxygenation

A unique, high surface area Co3O4/SiO2–Al2O3 catalytic system has been developed for the selective deoxygenation of biomass to high quality diesel-grade hydrocarbons.

Characterization of Urea versus HMTA in the Preparation of Zinc Oxide Nanostructures by Solution-Immersion Method Grown on Gold-Seeded Silicon Substrate

2011 ◽  
Vol 364 ◽  
pp. 45-49 ◽  
Author(s):  
Azlinda Ab Azlinda ◽  
Zuraida Khusaimi ◽  
Saifollah Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Zinc Oxide ◽  
Silicon Substrate ◽  
High Surface ◽  
High Surface Area ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Immersion Method ◽  
Oxide Nanostructures

Zinc oxide (ZnO) nanostructures prepared by immersion method were successfully grown on gold-seeded silicon substrate using Zinc nitrate hexahydrate (Zn (NO3)2.6H2O) as a precursor, separately stabilized with non-toxic urea (CH4N2O) and hexamethylene tetraamine (HMTA). The effect of changing the stabilizer of ZnO solution on the crystal structure, morphology and photoluminescence properties of the resultant ZnO is investigated. X-ray diffraction of the synthesized ZnO shows hexagonal zincite structure. The morphology of the ZnO was characterized using Field Emission Scanning Electron Microscope (FESEM). The growth of ZnO using urea as stabilizer shows clusters of ZnO nanoflower with serrated broad petals were interestingly formed. ZnO in HMTA showed growth of nanorods. The structures has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors. The formation of ZnO nanostructures is found to be significantly affected by the stabilizer.

scholarly journals Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Pavuluri Srinivasu ◽  
Surya Prakash Singh ◽  
Ashraful Islam ◽  
Liyuan Han
Keyword(s):  
Zinc Oxide ◽  
Solar Cells ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Dye Sensitized Solar Cells ◽  
Oxide Material ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Nanocrystalline Zinc Oxide

High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

Hierarchically porous and nitrogen, sulfur-codoped graphene-like microspheres as a high capacity anode for lithium ion batteries

2015 ◽  
Vol 51 (11) ◽  
pp. 2134-2137 ◽  
Author(s):  
Dongfei Sun ◽  
Juan Yang ◽  
Xingbin Yan
Keyword(s):  
Lithium Ion Batteries ◽  
Surface Area ◽  
Anode Material ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Lithium Ion ◽  
The Novel ◽  
Heteroatom Doping ◽  
Hierarchically Porous

The novel hierarchically porous and nitrogen, sulfur-codoped graphene-like microspheres are constructed as the anode material for lithium ion batteries. High surface area and efficient heteroatom doping provide high capacity and enhanced cycling stability.

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