bet equation for surface area determination BET method - BET surface areaplot BET surface areas Unveiling Material Properties: The BET Equation for Surface Area Determination

BET equationderivation The Brunauer-Emmett-Teller (BET) method stands as a cornerstone in the field of materials science and chemistry, offering a robust approach to surface area determinationReliable surface area determination of powders and meso Its widespread adoption stems from its ability to provide a reliable measure of the external and internal surface area of a material, a critical parameter influencing phenomena such as catalysis, adsorption, and separation作者：G Fagerlund·1973·被引用次数：430—The theoretical background of the adsorption isothermequationof Brunauer, Emmett and Teller is reviewed, together with the experimental techniques availa. At the heart of this method lies the Brunauer–Emmett–Teller (BET) equation, a theoretical framework that allows for the calculation of the monolayer capacity of adsorbed gas on a solid surface, from which the specific surface area can be derivedHow Reproducible are Surface Areas Calculated from the BET Therefore, understanding and applying the BET equation is fundamental for accurate surface area determination6.3 BET Theory and Surface Area Determination

Developed in the 1930s, the BET theory is based on the principles of multilayer adsorption It assumes that gas molecules can condense on the surface in multiple layers, with each layer being held by van der Waals forcesDetermination of the specific surface area (BET surface area) The BET equation relates the amount of gas adsorbed at a given relative pressure to the surface area Specifically, it allows for the calculation of the monolayer capacity by analyzing the adsorption isotherm, which plots the amount of gas adsorbed versus the relative pressure of the adsorbateThe BET equation, derived from adsorption-desorption equilibrium,helps calculate specific surface area. This is vital for characterizing materials used in  This isotherm provides a fingerprint of the material's interaction with the adsorbate gasBET surface area analysis - Solid State Chemistry @Aalto

The practical application of the BET method involves performing adsorption-desorption experiments, most commonly using nitrogen gas at cryogenic temperatures (typically 77 K)6.3 BET Theory and Surface Area Determination The choice of adsorbate is crucial; nitrogen is favored due to its readily available monolayer capacity and its tendency to physisorb reversibly onto many surfacesDetermination of specific surface by the BET method The experiment yields an adsorption isotherm, which is then linearized and plotted according to a specific form of the BET equationSurface Area Estimation Replacing the Brunauer–Emmett The linear region of this plot is crucial for accurate surface area determinationBET surface area analysis - Solid State Chemistry @Aalto The slope and intercept of this linear BET plot are then used to calculate the monolayer capacity, denoted as $V_m$作者：FS Irwansyah·被引用次数：58—TheBET methodprovides a means to calculate the monolayer capacity of the gas adsorbed on the material's surface, and from there, the specificsurface areaof 

Once the monolayer capacity ($V_m$) is determined, the specific surface area ($S$) can be calculated using the following formula:

$S = \frac{V_m \times N \times \sigma}{M}$

Where:

* $V_m$ is the monolayer capacity (volume of gas adsorbed per unit mass of sample)Determination of the specific surface area (BET surface area)

* $N$ is Avogadro's number ($6How reproducible are surface areas calculated from the 022 \times 10^{23}$ molecules/mol)TheBrunauer-Emmett-Teller (BET) methodis the most common method for the evaluation of specific surface areas. It is applicable to sorption isotherms Type 

* $\sigma$ is the cross-sectional area occupied by one adsorbate molecule (eBET surface area analysis - Solid State Chemistry @Aaltog佛历2565523—TheBrunauer–Emmett–Teller (BET) equationis arguably one of the most used equations in physical chemistry and porosimetry. Since its conception , 16佛历2565523—TheBrunauer–Emmett–Teller (BET) equationis arguably one of the most used equations in physical chemistry and porosimetry. Since its conception 2 $\text{\AA}^2$ for nitrogen at 77 K)The document explains theBET equationand how it is used to calculate surface area based on nitrogen gas absorption measurements. It also notes some 

* $M$ is the molar mass of the adsorbate (eg作者：C Schlumberger·2022·被引用次数：52—TheBET methodallows one to determine reliablesurface areasof non-porous, macroporous (pores >50 nm) and most mesoporous (2 nm ≤ pores ≤50 nm) materials, , 28BET surface area analysis | PDF013 g/mol for nitrogen)How reproducible are surface areas calculated from the

This formula effectively translates the amount of gas required to form a single molecular layer on the surface into a quantifiable measure of the surface areaEvaluation of the BET Theory for the Characterization The resulting value is typically expressed in units of square meters per gram ($\text{m}^2/\text{g}$)作者：C Schlumberger·2022·被引用次数：52—TheBET methodallows one to determine reliablesurface areasof non-porous, macroporous (pores >50 nm) and most mesoporous (2 nm ≤ pores ≤50 nm) materials, 

It is vital to acknowledge the limitations and considerations when employing the Brunauer-Emmett-Teller (BET) equationBET Surface Area analysis - measurement and method The BET equation is generally not valid at higher partial pressures, where multilayer adsorption deviates significantly from the model's assumptions and capillary condensation effects can become dominant, particularly in materials with larger poresBET surface area analysis - Solid State Chemistry @Aalto The choice of the appropriate pressure range for the BET calculation is therefore critical for obtaining meaningful and reproducible resultsHow reproducible are surface areas calculated from the BET Researchers often focus on the relative pressure range between 0BET Surface Area analysis - measurement and method05 and 0作者：F Ambroz·2018·被引用次数：754—In this review, the applicability of theBET methodfor determiningsurface areasof MOFs with various pore widths is discussed. Reported 35 for optimal linearity of the BET plotHow Reproducible are Surface Areas Calculated from the Furthermore, the reproducibility of BET surface areas has been a subject of ongoing research, with variations in reported areas sometimes leading to challenges in both academic and industrial settingsBET surface area analysis | PDF Careful experimental control and adherence to standardized procedures are paramount作者：JWM Osterrieth·2022·被引用次数：340—ThecalculationofBET surface areascauses a spread in reported areas, resulting in reproducibility problems in both academia and industry.

The BET method is particularly well-suited for determining the surface areas of non-porous, macroporous (pores >50 nm), and most mesoporous (2 nm $\le$ pores $\le$ 50 nm) materialsHow reproducible are surface areas calculated from the BET However, its applicability to microporous materials (pores < 2 nm) can be more complex, and in such cases, alternative methods or modifications to the BET analysis procedure might be necessary for accurate characterizationHow Reproducible are Surface Areas Calculated from the BET Despite these considerations, the BET method remains the standard for the characterization of many materials, and understanding the underlying equation is indispensable for anyone working with porous solids The determination of the surface area by the BET method continues to be a fundamental technique for material scientists, chemists, and engineers seeking to understand and manipulate the properties of diverse substancesHow to Read and Determine the Specific Surface Area of The principles of BET adsorption isotherm equation and their practical implications are essential knowledge for anyone involved in surface area determination作者：F Ambroz·2018·被引用次数：754—In this review, the applicability of theBET methodfor determiningsurface areasof MOFs with various pore widths is discussed. Reported