Electron Microscopy of Porous Materials—The Structure of a Commercial Alumina Catalyst Support

1971 ◽  
Vol 29 ◽  
pp. 154-155
Author(s):  
D. Faulkner ◽  
N. H. Sagert ◽  
E. E. Sexton ◽  
R. C. Styles
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Catalyst Support ◽  
Chemical Properties ◽  
Carbon Substrate ◽  
High Porosity ◽  
Transmission Electron Micrograph ◽  
Electron Micrograph ◽  
Direct Technique

Many practical catalysts consist of a metal supported on a stable material. The activity of such a system depends not only on the chemical properties of the metal and support, but also on certain physical properties of the support such as surface area, pore volume and pore size distribution. Indirect information on the pore structure of the support material can be obtained from low-temperature nitrogen adsorption experiments, but a more direct technique for obtaining this information is to examine the material in the electron microscope.The material chosen for this study was a high porosity alumina obtained from Englehard. The pore size distribution as supplied by the manufacturer indicated 0.24 cc of pores/g in the range 0-100Å, and 0.16 cc/g > 100Å. Figure 1 is a scanning electron micrograph of the surface of the material. Although no great detail can be resolved, the surface is obviously uneven, and gives the impression of being somewhat fibrous in texture. Figure 2 is a transmission electron micrograph of the same material. This sample was prepared by crushing the material and dispersing the particles on a carbon substrate.

High Porosity SiC Ceramics with a Narrow Pore Size Distribution

2008 ◽  
Vol 368-372 ◽  
pp. 840-842 ◽  
Author(s):  
Li Min Shi ◽  
Hong Sheng Zhao ◽  
Ying Hui Yan ◽  
Chun He Tang
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Phenolic Resin ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Narrow Pore Size Distribution ◽  
X Ray ◽  
Sic Ceramics ◽  
Porous Sic

Using the coat mix process, porous SiC ceramics are fabricated using commercially available silicon powders and phenolic resin as the starting materials. The phase composition, morphology, pore size and pore size distribution of the obtained products are characterized by X-ray diffraction, scanning electron microscopy and mercury intrusion porosimeter. The results show that high porosity SiC ceramics with a narrow pore size distribution can be fabricated at 1500°C in vacuum by the coat mix process. The open pore porosity can reach up to 60%. The pore size varies in the range of 1-6 'm.

Preparation of Mesoporous Alumina Using Hexamethyl Disilylamine as Substitute Solvent

2013 ◽  
Vol 773 ◽  
pp. 482-486 ◽  
Author(s):  
Su Min Cui ◽  
Li Li Ren ◽  
Feng Chao Cao
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Supercritical Drying ◽  
Mesoporous Alumina ◽  
Bet Surface Area ◽  
High Porosity ◽  
Drying Method

Mesoporous inorganic alumina with framework walls has been synthesized using a new and simple non-supercritical drying method. As a substitute solvent, hexamethyl disilylamine (HMDS) plays a definitive part for synthesis of the mesoporous alumina due to its special characters. The resulting alumina product shows high BET surface area, concentrated distribution of diameter and high porosity. The pore size distribution of alumina we prepared is concentrated around 11nm. Its structure still maintained stable and the BET surface area could reach up to 413.4593m2/g after being calcined at 800°C.

scholarly journals Innovative Material Can Mimic Coral and Boulder Reefs Properties

2021 ◽  
Vol 8 ◽  
Author(s):  
Lucia Margheritini ◽  
Per Møldrup ◽  
Rasmus Lund Jensen ◽  
Kirstine Meyer Frandsen ◽  
Yovko Ivanov Antonov ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Low Voltage ◽  
Artificial Reef ◽  
Total Porosity ◽  
Electrical Current ◽  
High Porosity ◽  
Mineral Deposition

Low-Voltage Mineral Deposition technology (LVMD), widely known as Biorock, has previously been suggested as support for coral reef restoration, as hypothesized high porosity, wide pore-size distribution and connectivity, and good strength properties may facilitate biological functions (for example larvae settlement) and durability. In this technology, very low voltage induces an electrical current that initiates precipitation and accretion of hard minerals (aragonite and calcite) on a metal in seawater. This technology has been discussed mainly for its biological value, while this paper wants to highlight also its engineering value as artificial reef material. Indeed, some of the properties that makes it valuable in one domain are also supporting its use in the other. Because the metal on which the precipitation takes place can be of any shape and size, so can the artificial reef and its mechanical strength characteristics are above the ones of corals and similar to concrete, indicating adequate durability. Coral and boulder reefs suffering from degradation have severe implications on biodiversity, protection from flooding, and cultural value and therefore understanding how to persevere and re-establish these ecosystems is central for sustainable intervention in the marine environment. By comparing chemical-physical characteristics of Coral Porites Exoskeleton (CPE), one typical reef building coral type, LVMD and High-Voltage Mineral Deposition (HVMD), we show that they possess highly similar properties including chemical composition, density, total porosity, pore-size distribution, physical and chemical heterogeneity, total and external surface areas, and comparable mechanical strength.

pyGAPS: A Python-Based Framework for Adsorption Isotherm Processing and Material Characterisation

2019 ◽  
Author(s):  
Paul Iacomi ◽  
Philip L. Llewellyn
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Isosteric Heat ◽  
Material Characterisation ◽  
Mixture Adsorption ◽  
Surface Energetics ◽  
Adsorption Processing ◽  
User Friendly

Material characterisation through adsorption is a widely-used laboratory technique. The isotherms obtained through volumetric or gravimetric experiments impart insight through their features but can also be analysed to determine material characteristics such as specific surface area, pore size distribution, surface energetics, or used for predicting mixture adsorption. The pyGAPS (python General Adsorption Processing Suite) framework was developed to address the need for high-throughput processing of such adsorption data, independent of the origin, while also being capable of presenting individual results in a user-friendly manner. It contains many common characterisation methods such as: BET and Langmuir surface area, t and α plots, pore size distribution calculations (BJH, Dollimore-Heal, Horvath-Kawazoe, DFT/NLDFT kernel fitting), isosteric heat calculations, IAST calculations, isotherm modelling and more, as well as the ability to import and store data from Excel, CSV, JSON and sqlite databases. In this work, a description of the capabilities of pyGAPS is presented. The code is then be used in two case studies: a routine characterisation of a UiO-66(Zr) sample and in the processing of an adsorption dataset of a commercial carbon (Takeda 5A) for applications in gas separation.

Sign in / Sign up

Export Citation Format

Share Document