Project Details Standardized reporting of gas adsorption isotherms

Project No.:
Start Date:
23 September 2021
End Date:


To provide scientists who study the adsorption properties of porous materials and other high surface area materials (zeolites, mesoporous materials, metal-organic frameworks, porous carbons and oxides, nanoparticles, nanotubes, 2D materials etc.) with a standardized electronic file format (Adsorption Information File, AIF) that is readily human and machine readable for publishing, exchanging and archiving data that quantifies the adsorption of gases, vapors and gas mixtures.


Porous materials play an important role for energy transformation, storage and environmental applications. Characterization of materials by gas adsorption (Nitrogen, Argon, CO2 etc.) enables pore size analysis (IUPAC project 2010-009-1-100) and, importantly, functional demonstration (gas separation, gas storage etc.). Various methods can be used for measuring gas adsorption, the most common methods are based on volumetric and gravimetric approaches.

In other fields of research (e.g. crystallography) it has become routine to deposit information in the format of a human readable text file for archiving primary data (Crystallographic Information File, CIF). However, exact primary adsorption data are rarely made accessible with publications in an electronic format. In many publications, adsorption data are only reported as graphs. This leads to a severe loss of information, and is particular present in the low-pressure region of isotherms, which conceals important details about the narrow micropore filling and the adsorbate-adsorbent interactions (DOI:10.1021/acs.langmuir.1c00122). For the evaluation of these structural details, including the reproducible extraction of published pore size distributions, specific surface areas and more, it is necessary to make primary data available. Unfortunately, the various file formats produced from commercial adsorption equipment are currently not suitable for data exchange and archiving.

Hence, establishing a human- and machine-readable standardized file format for adsorption data has the following purpose:
– archiving primary adsorption data as supplementary information in publications,
– ensure clear communication of the meaning of isotherm data via a cohesive vocabulary and ontology of adsorption measurements,
– ensure reproducible adsorption measurements,
– enable replicable extraction of secondary measures (BET surface area, pore size distribution etc.) from primary data,
– enable a wider access of published data for advanced computational analysis (adsorption simulation, machine learning),

The task group will develop recommendations for
– single component gas adsorption isotherms
– single component vapor adsorption isotherms
– high pressure adsorption isotherms
– mixture phase adsorption data

The group shall also provide an online framework to enable the extraction of data output from adsorption equipment into a standardized adsorption information file that can be further edited by the user (proof of principle example

In the preparation of this project, the task group has already established a preliminary file format and set of tools to treat single gas component isotherms:


In the preparation of this project, the task group has already established a preliminary file format and set of tools to treat single gas component isotherms:

Page last update 23 Sep 2021