Physical adsorption of gas molecules, otherwise known as Physisorption, is a technique that is used to determine the specific surface area and pore size distribution of powders. It plays a critical role in the analysis of catalysts, adsorbents and other porous materials, where the surface area and porosity significantly impact their functional performance.

The specific surface area affects the material's surface interactions with gases or liquids such as adsorption capacity, dissolution rates and reaction rates. Pore size analysis allows for a deeper understanding of a material’s microstructure, distinguishing between micro-, meso- and macro-porous samples, which are useful in fields such as catalysis or gas separation.

Dynamic flow and static volumetric methods are two common approaches used to conduct physisorption measurements. The dynamic flow method measures gas adsorption by flowing it over the sample to allow fast routine analysis and higher sample throughput. It is suitable for mesoporous and macroporous materials. On the other hand, static volumetric method involves measuring the adsorption at equilibrium points. It is suitable for all pore sizes, especially micropores, and provides higher sensitivity and accuracy.

Discover our comprehensive range of physisorption instruments to cater to different analytical requirements.

Physisorption has historically been carried out with nitrogen as the adsorbate gas. However, it has several drawbacks as nitrogen has a non-spherical molecular shape and electric quadrupole moment, which can skew specific surface area data.

Both ISO 9277 and IUPAC recommend substituting nitrogen with argon (87 K) for more accurate data. However, sourcing for liquid argon to maintain the boiling temperature at 87 K during the test can be challenging and costly.

The cryoTune is an innovative temperature control device that allows easily accessible liquid nitrogen to achieve the required cooling temperature. It supports a wide range of adsorptive gases, including methane, ethane, propane, n-butane, oxygen, carbon dioxide, SF₆, and more. cryoTune gives you the flexibility to perform sorption experiments with various gases and measure isotherms at different temperatures, allowing for detailed thermodynamic calculations like the isosteric heat of adsorption. As an added benefit, it also reduces the duration of the analysis.

The cryoTune is compatible with any brand of surface area analyser in the market. It can easily be attached to an existing instrument to open new research possibilities and directions.

Unlock the full potential of gas sorption analysis with the cryoTune now!

Chemisorption is technique that is used to characterise the behaviour of heterogeneous catalysts. It can be used to determine essential parameters such as percentage of metal dispersion, temperature which at it becomes catalytically active, strength of active sites, activation energy and many more. These insights are crucial for evaluating catalyst performance, stability, and selectivity in chemical reactions, ultimately influencing the efficiency of industrial processes.

This method involves the chemical interaction between gas molecules and the surface of a catalyst, making it crucial for applications in industries such as petrochemicals, energy and environmental engineering.

Discover our range of fully automated chemisorption instruments to cater to different analytical requirements.

The Master 400 quadrupole mass spectrometer can be used to identify and quantify evolved gases that emerge during chemisorption. It can also be paired with other instruments such as breakthrough analysers and thermogravimetric analysers (TGA).

The breakthrough analyser is an essential tool to gain insights into the performance of catalysts and adsorbent materials under process-relevant conditions. Designed to replicate industrial environments on a lab scale, this instrument allows researchers and engineers to observe how materials behave before scaling up for commercial applications.

Breakthrough curves are generated, which plot the concentration of an adsorptive species at the outlet of an adsorption column over time. From activated carbon and zeolites to innovative metal-organic frameworks (MOFs), the breakthrough analyser provides a clear understanding of a newly synthesised material’s capabilities in capturing and separating targeted components. Key parameters such as sorption capacity, sorption selectivity or affinity, sorption kinetics, regenerability and cycle stability can be determined.

The data generated is invaluable for the development of materials across various fields, including carbon capture from exhaust gases, the removal of carbon dioxide from methane in natural gas purification, and hydrogen purification through pressure swing adsorption.

A gas pycnometer measures the Skeletal Density, also known as Apparent Density, of a powder through the displacement of Helium gas. Helium has a very small atomic size that can penetrate extremely narrow pores in a solid. This allows the total volume, excluding open pore volume, to be measured. The mass of the sample over the measured volume gives the Skeletal Density (the skeleton of the material).

The Skeletal Density can be multiplied with the BET Specific Surface Area (from physisorption) to derive the Volume Specific Surface Area (VSSA). This can be used to screen for nanomaterials.