Zirconia Aerogels with High Surface Area Derived from Sols Prepared by Electrolyzing Zirconium Oxychloride Solution:  Comparison of Aerogels Prepared by Freeze-Drying and Supercritical CO2(l) Extraction

2007 ◽  
Vol 111 (50) ◽  
pp. 18738-18743 ◽  
Author(s):  
Zhongqiang Zhao ◽  
Dairong Chen ◽  
Xiuling Jiao
Keyword(s):  
Surface Area ◽  
Supercritical Co2 ◽  
Freeze Drying ◽  
High Surface ◽  
High Surface Area ◽  
Zirconium Oxychloride

Azeotropic distillation, ethanol washing, and freeze drying on coprecipitated gels for production of high surface area 3Y–TZP and 8YSZ powders: A comparative study

2015 ◽  
Vol 41 (10) ◽  
pp. 14148-14156 ◽  
Author(s):  
R.H. Piva ◽  
D.H. Piva ◽  
J.J. Pierri ◽  
O.R.K. Montedo ◽  
M.R. Morelli
Keyword(s):  
Comparative Study ◽  
Surface Area ◽  
Freeze Drying ◽  
High Surface ◽  
High Surface Area ◽  
Azeotropic Distillation ◽  
Ethanol Washing

scholarly journals Multi-Fold Enhancement in Compressive Properties of Polystyrene Foam Using Pre-delaminated Stearate Functionalized Layer Double Hydroxides

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Emmanuel O. Ogunsona ◽  
Koffi L. Dagnon ◽  
Nandika Anne D'Souza
Keyword(s):  
Surface Area ◽  
Supercritical Co2 ◽  
Hydrophobic Interactions ◽  
High Surface ◽  
High Surface Area ◽  
Bubble Nucleation ◽  
Environmentally Benign ◽  
Compressive Properties ◽  
Layer Double Hydroxides ◽  
Double Hydroxides

Developing an environmentally benign styrene foam is a critical environmental need. Supercritical CO2 use in foams has proven to be a valuable path. Adding fillers to increase bubble nucleation has been pursued concurrently. A prominent filler used is high surface area fillers, such as smectic clays. However, all studies to date show a limit of 152% in compressive moduli and 260% in the compressive stress. The values, even with such gains, limit structural application. A seminal work in 1987 by Suh and Cotton proved that carbonyl linkages in calcium carbonates and CO2 interact and impact nucleation efficiency and performance in supercritical CO2 foams. In this paper, a high surface area clay (layer double hydroxides) which begins in an exfoliated state, then functionalized with a long chain alkyl carboxylate (stearic acid) is synthesized. The result is a remarkable multi-fold improvement to the compressive properties in comparison to polystyrene (PS); a 268% and 512% increase in compressive modulus and strength, respectively. Using a pre-delaminated approach, the higher surface area was achieved in the clays. The presence of the stearate improved the interactions between the clay galleries and PS through hydrophobic-hydrophobic interactions. The glass transition temperature of the nanocomposites was observed to shift to higher values after foaming. The results point to a new path to increase performance using a pre-delaminated clay with functional groups for environmentally benign foams.

scholarly journals Niobium oxide prepared through a novel supercritical-CO2-assisted method as a highly active heterogeneous catalyst for the synthesis of azoxybenzene from aniline

2019 ◽  
Vol 21 (21) ◽  
pp. 5852-5864 ◽  
Author(s):  
Yehan Tao ◽  
Bhawan Singh ◽  
Vanshika Jindal ◽  
Zhenchen Tang ◽  
Paolo P. Pescarmona
Keyword(s):  
High Activity ◽  
Surface Area ◽  
Heterogeneous Catalyst ◽  
Oxidative Coupling ◽  
Supercritical Co2 ◽  
Niobium Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active

High-surface area Nb2O5 nanoparticles synthesised by a novel supercritical-CO2-assisted method displayed extremely high activity as heterogeneous catalyst in the oxidative coupling of aniline to azoxybenzene using the green oxidant H2O2.

Atmospheric freeze drying for the reduction of powder electrostatics of amorphous, low density, high surface area pharmaceutical powders

2012 ◽  
Vol 39 (2) ◽  
pp. 205-217 ◽  
Author(s):  
K. P. O’Donnell ◽  
Z. Cai ◽  
P. Schmerler ◽  
R. O. Williams
Keyword(s):  
Surface Area ◽  
Freeze Drying ◽  
High Surface ◽  
High Surface Area ◽  
Pharmaceutical Powders ◽  
Low Density

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

scholarly journals Rugae-like FeP nanocrystal assembly on a carbon cloth: an exceptionally efficient and stable cathode for hydrogen evolution

Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  
Keyword(s):  
Gas Phase ◽  
Surface Area ◽  
Hydrogen Evolution ◽  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Efficiency ◽  
Carbon Cloth ◽  
Nanocrystal Assembly

High surface area FeP nanosheets on a carbon cloth were prepared by gas phase phosphidation of electroplated FeOOH, which exhibit exceptionally high catalytic efficiency and stability for hydrogen generation.

High Surface Area NiCoP Nanostructure as Efficient Water Splitting Electrocatalyst for the Oxygen Evolution Reaction

2021 ◽  
pp. 111312
Author(s):  
Sisir Maity ◽  
Dheeraj Kumar Singh ◽  
Divya Bhutani ◽  
Suchitra Prasad ◽  
Umesh V. Waghmare ◽  
...  
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Surface ◽  
High Surface Area

scholarly journals Fast synthesis of high surface area bio-based porous carbons for p-nitrophenol removal

MethodsX ◽  
2021 ◽  
pp. 101464
Author(s):  
Yichen Wu ◽  
Nan Zhang ◽  
Charles-François de Lannoy
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Porous Carbons ◽  
Fast Synthesis
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