The control of Pt and Ru nanoparticle size on high surface area supports

2014 ◽  
Vol 16 (48) ◽  
pp. 26431-26435 ◽  
Author(s):  
Qiuli Liu ◽  
Upendra A. Joshi ◽  
Kevin Über ◽  
John R. Regalbuto
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Pt Nanoparticles ◽  
Nanoparticle Size ◽  
Particle Sizes ◽  
Electrostatic Adsorption ◽  
Strong Electrostatic Adsorption ◽  
Metal Precursors

Supported Ru and Pt nanoparticles were synthesized by the method of strong electrostatic adsorption and subsequently treated to achieve a series of catalysts with particle sizes ranging from 1 to 8 nm. This methodology allows the control of particle size applicable to high surface area supports with common metal precursors.

Synthesis and characterization of mesalamine silica nanoparticles

2021 ◽  
Vol 16 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Ramya Krishna Nakkala ◽  
Prasanna Kumar Desu ◽  
Vikas Jhawat
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Silica Nanoparticle ◽  
Water Soluble ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Wide Range

Background: Nanoparticles made of silica are new materials that can be used in a wide range of drug delivery methods because they are biocompatible and biodegradable. Mesalamine, a classic water-soluble medication, remains loaded into the synthesized silica nanoparticle and is considered for sustained release proficiency. Precipitation approach using high surface area and pore volume tetraethyl orthosilicate yielded mesalamine-loaded silica nanoparticles. Methods: The drug-loaded nanoparticle was created and produced using two different techniques. Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, Brauer Emmett teller, scanning electron microscopy, particle size measurements, and dissolution investigations have all been used to analyse the substance in some way or another. Results: Because of the high surface area, well-known results like the complete silica nanoparticle created using method-2 remained mesoporous. The onset peak of the method-2 formulation's DSC was 182.27°c, and the offset peak was 192.14°c, consistent with the DSC results. The particle size range varies from 205-225nm. The results demonstrate that the uptake of the mesalamine by burst release it for 30 minutes initial, followed by sustained maintenance of dose even after 240 minutes. The results indicate that the loading process has an effect on the extent of loading. When silica nanoparticles were impregnated with mesalamine, the amount of the drug contained was significantly higher than when they were wetted. Conclusion: In addition, the XRD results show that both the pure mesalamine and the formulation did not show any polymorphic deviation.

scholarly journals Ruthenium particle size and cesium promotion effects in Fischer–Tropsch synthesis over high-surface-area graphite supported catalysts

2017 ◽  
Vol 7 (5) ◽  
pp. 1235-1244 ◽  
Author(s):  
José L. Eslava ◽  
Xiaohui Sun ◽  
Jorge Gascon ◽  
Freek Kapteijn ◽  
Inmaculada Rodríguez-Ramos
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Supported Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

The effect of ruthenium particle size on Fischer–Tropsch synthesis has been studied at 513 K, H2/CO = 2 and 15 bar.

scholarly journals Synthesis of Nanostructured TiO2 Microparticles with High Surface Area

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1512
Author(s):  
Lev Matoh ◽  
Boštjan Žener ◽  
Tina Skalar ◽  
Urška Lavrenčič Štangar
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Tio2 Particle ◽  
Nanostructured Tio2 ◽  
Degradation Rates

Hydrothermal reactions represent a simple and efficient method for the preparation of nanostructured TiO2 particles that could be of interest as photocatalysts or catalytic supports. Although the particle size is in the range of 2–5 µm, the nanostructures composing the particles ensure a large specific surface area with values above 100 m2/g. The effects of the different synthesis parameters on the morphology, photocatalytic activity, and stability of the prepared material were studied. The surface morphology of the prepared TiO2 powders was studied by scanning electron microscopy (SEM). To further characterize the samples, the specific surface area for different morphologies was measured and the photocatalytic activity of the prepared powders was tested by degrading model pollutants under UV irradiation. The results show that the initial morphology had little effect on the photocatalytic properties. On the other hand, the final calcination temperature significantly increased the degradation rates, making it comparable to that of P25 TiO2 (particle size 20–30 nm).

The Effect of the Particle Size on the Kinetics of CO Electrooxidation on High Surface Area Pt Catalysts

2005 ◽  
Vol 127 (18) ◽  
pp. 6819-6829 ◽  
Author(s):  
Matthias Arenz ◽  
Karl J. J. Mayrhofer ◽  
Vojislav Stamenkovic ◽  
Berislav B. Blizanac ◽  
Tada Tomoyuki ◽  
...  
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Pt Catalysts ◽  
Co Electrooxidation ◽  
Kinetics Of

scholarly journals Efficiency of solar water disinfection photocatalized by titanium dioxide of varying particle size

2007 ◽  
Vol 5 (3) ◽  
pp. 335-340 ◽  
Author(s):  
F. M. Salih ◽  
A. E. Pillay
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Tio2 Particle ◽  
Water Disinfection ◽  
Local Concentration ◽  
Bacterial Cells ◽  
Radical Interaction

Titanium dioxide photocatalysed water disinfection is induced by the interaction of light with TiO2, which generates highly reactive free hydroxyl radicals (OH•). These free radicals create lethal damage that leads to bacterial death. Normally, decreasing TiO2 particle size increases the area of light interaction. This may possibly increase the concentration of OH• generated and hence increases disinfection efficiency. Moreover, decreasing the particle size increases the force of attraction between the particles and cells, which could create aggregates that may contribute to the local OH• concentration. In the present investigation cells of Escherichia coli were used as the test microorganism, TiO2 as the photocatalyst and sunlight as the light source. Four different surface areas of TiO2 particles corresponding to 10, 50, 80–100 and ≥300 m2 g−1 were tested at a concentration of 1 g l−1. Disinfection efficiency increased with increasing the surface area producing a maximum between 80–100 m2 g−1 followed by a reduction at ≥300 m2 g−1. The reduction in the efficiency at this relatively high surface area was attributed to the increase in the local concentration of OH•. This increase may be high enough to initiate radical-radical interaction that would compete with bacterial cells and reduce the chance of bacterial cell-radical interaction taking place. Moreover, the phenomenon of TiO2 aggregation with bacterial cells plays an important role, and the extent of aggregation increases with decreasing particle size. Such aggregation could augment the concentration of OH• within the cell vicinity. This suggests that surface area is a key factor in determining the efficiency of disinfection, and that concentration is a vital factor.

The Microstructure and Properties of Framework Zirconium Phosphates Based Nanocomposites -Catalysts of Alkane Isomerization

1999 ◽  
Vol 581 ◽  
Author(s):  
Vladislav A. Sadykov ◽  
S. N. Pavlova ◽  
G. V. Zabolotnaya ◽  
R. I. Maximovskaya ◽  
D. I. Kochubei ◽  
...  
Keyword(s):  
Surface Area ◽  
Surface Properties ◽  
Spectral Methods ◽  
High Surface ◽  
High Surface Area ◽  
Pt Nanoparticles ◽  
Microstructure And Properties ◽  
Alkane Isomerization ◽  
Zirconium Phosphates ◽  
Properties Of Composites

ABSTRACTThe structure and surface properties of composites based upon high-surface-area framework zirconium phosphates with supported WO3, MoO3 and Pt nanoparticles were studied by using combination of structural and spectral methods. The effect of these promoters on performance of zirconium phosphates in the reaction of pentane and hexane isomerization is considered.

Photocatalytic H2 generation on macro-mesoporous oxide-supported Pt nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (22) ◽  
pp. 18198-18203 ◽  
Author(s):  
Song Yi Moon ◽  
Brundabana Naik ◽  
Kwangjin An ◽  
Sun Mi Kim ◽  
Jeong Young Park
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
High Surface ◽  
High Surface Area ◽  
Pt Nanoparticles ◽  
H2 Generation ◽  
Mesoporous Oxide ◽  
Photocatalytic H2 Generation ◽  
Mesoporous Oxides

Photocatalysts with high surface area and crystalline walls are synthesized through a dual-templating strategy. The role of ordered macro-mesoporous oxides with crystalline walls was studied for photocatalytic water splitting to generate H2.

La activated high surface area titania float for the adsorption of Pb(ii) from aqueous media

2018 ◽  
Vol 42 (2) ◽  
pp. 1067-1077 ◽  
Author(s):  
Shwetharani R. ◽  
Poojashree A. ◽  
Geetha R. Balakrishna ◽  
Jyothi M. S.
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Surface Area ◽  
Metal Ion ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Heavy Metal Ion ◽  
Enhanced Adsorption

Smaller particle size with higher surface area La-TiO2 fabricated float depicts enhanced adsorption of hazardous heavy metal ion Pb2+, present in the aqueous media and the float makes the process easy and reusable.

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