Pore Size Analysis of Activated Carbons from Argon and Nitrogen Porosimetry Using Density Functional Theory

Langmuir ◽  
2000 ◽  
Vol 16 (11) ◽  
pp. 5041-5050 ◽  
Author(s):  
Robert J. Dombrowski ◽  
Daniel R. Hyduke ◽  
Christian M. Lastoskie
Keyword(s):  
Density Functional Theory ◽  
Pore Size ◽  
Density Functional ◽  
Activated Carbons ◽  
Size Analysis ◽  
Functional Theory ◽  
Pore Size Analysis

Quenched solid density functional theory and pore size analysis of micro-mesoporous carbons

Carbon ◽  
2009 ◽  
Vol 47 (7) ◽  
pp. 1617-1628 ◽  
Author(s):  
Alexander V. Neimark ◽  
Yangzheng Lin ◽  
Peter I. Ravikovitch ◽  
Matthias Thommes
Keyword(s):  
Density Functional Theory ◽  
Pore Size ◽  
Density Functional ◽  
Size Analysis ◽  
Mesoporous Carbons ◽  
Functional Theory ◽  
Solid Density ◽  
Pore Size Analysis

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.

scholarly journals Graphene Oxide: Study of Pore Size Distribution and Surface Chemistry Using Immersion Calorimetry

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1492
Author(s):  
Carlos A. Guerrero-Fajardo ◽  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján
Keyword(s):  
Density Functional Theory ◽  
Graphene Oxide ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Density Functional ◽  
Local Density ◽  
Donor Number ◽  
Immersion Enthalpy ◽  
Functional Theory

In this work, the textural parameters of graphene oxide (GO) and graphite (Gr) samples were determined. The non-local density functional theory (NLDFT) and quenched solid density functional theory (QSDFT) kernels were used to evaluate the pore size distribution (PSD) by modeling the pores as slit, cylinder and slit-cylinder. The PSD results were compared with the immersion enthalpies obtained using molecules with different kinetic diameter (between 0.272 nm and 1.50 nm). Determination of immersion enthalpy showed to track PSD for GO and graphite (Gr), which was used as a comparison solid. Additionally, the functional groups of Gr and GO were determined by the Boehm method. Donor number (DN) Gutmann was used as criteria to establish the relationship between the immersion enthalpy and the parameter of the probe molecules. It was found that according to the Gutmann DN the immersion enthalpy presented different values that were a function of the chemical groups of the materials. Finally, the experimental and modeling results were critically discussed.

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