ZSM-5 RM 8852

CO2in ZSM-5

Artistic Rendition

0 1 2 3 4 5 6 7

0

1

2

3

4 nex ( mmol / g ) P (MPa) CH4

 / Zeolite Y (RM 8850)

0 1 2 3 4

0

1

2

3nex ( mmol / g) P (MPa)

CO2 / ZSM-5 (RM 8852)

NIST Facility for Adsorbent Characterization & Testing (FACT Lab)

Adsorbent materials have many applications, including hydrogen

and methane storage, gas separation, catalysis, methane 

conversion, and natural gas purification.

Reproducibility of high-pressure sorption isotherm measurements 

has proved to be a challenge, slowing the development of new 

materials and associated applications. In part, these experimental 

difficulties are linked to the lack of standardized measurement 

protocols, reference materials, and reference data.

To address these needs, NIST in partnership with the Advanced

Research Projects Agency—Energy (ARPA-E), initiated a program

to develop reference materials, reference data, and measurement 

protocols to improve adsorption metrology. 

Application Areas

Research Activities

The performance of an adsorbent is typically determined by measuring an

adsorption isotherm, a plot of gas uptake as a function of equilibrium pressure at

a fixed temperature. To address the challenge of reproducibility in these

measurements, the FACT Lab has sponsored international, interlaboratory studies

to develop reference isotherms using NIST reference zeolitic materials.

Participating labs measured adsorption isotherms using the NIST Reference

Materials. All the resulting data were compiled and statistical methods were used

to evaluate the submitted data. From these data sets, a reference isotherm was

determined, resulting—for the first time—in a high-pressure reference isotherm

on a reference material. Two such studies have been completed: CO2 on ZSM-5

(NIST Reference Material 8852) at 20 °C up to 4.5 MPa and CH4 on Zeolite Y (NIST

Reference Material 8850) at 25 °C up to 7.5 MPa. (See figures to the right.)

SEPARATION

STORAGE

CONVERSION

POROSIMETRY

Power Plant Stack Exhaust:

Accelerated discovery of cost-efficient 

materials for separation of CO2 and trace 

gases from power plant exhausts requires an 

understanding of gas sorption mechanisms 

in complex gas mixtures.

Fuels:

The rational design of microporous 

materials for CH4 or H2 storage requires the 

optimization of the sorption kinetics in 

microporous adsorbents for efficient 

adsorption and release.

Gas-to-Liquid:

Innovation in catalysts for the conversion of 

methane to liquid fuels or others addedvalue chemicals demands data on 

interactions between reactant, products, 

and catalyst surface.

Additive Manufacturing:

Design optimization of porous 3D printed 

materials (hierarchical mesoporous 

bioactive polycaprolactone scaffolds, 

cathodes/anodes for lithium-ion microbatteries, lightweight cellular solids for 

aviation) requires high resolution pore 

analysis.
FACT Lab Instruments

The FACT Lab is equipped with five

state-of-the-art instruments, using

differing measurement principles and

offering complementary capabilities.

A summary of these instruments is

given in the table to the right. The

availability of complementary technologies in a single laboratory and the

capability to measure adsorption of

gas mixtures makes this laboratory

uniquely qualified to generate

reference adsorption data and to

explore the frontiers of adsorption

science.

Manometric Measurements

The four-channel manometric gas adsorption instrument covers a wide range

of pressures. Channel 2 features a small

sample holder (0.5 cm3) with a reduced

dead volume, for isotherm measurements on small-volume samples.

Facility Description Instrument Pmax Temperature range AST‡

Static Flow

Manometric

Ch1* 20 MPa 78 K – 780K Yes Yes -

Ch2 8 MPa 20 K – 670K Yes Yes -

Ch3* 100 kPa LN2, LAr, RT – 670K Yes Yes -

Ch4* 10 MPa RT – 670 K Yes Yes -

Gravimetric* 2 MPa 273 K – 773K Yes Yes Yes

Manometric& Gravimetric 9 MPa†

LN2, LAr, 273 K – 423K - Yes -

Manometric with chromatography 9 MPa† 283 K – 670 K / 283K – 323 K Yes Yes -

Pore size analyzer (manometric) 100 kPa RT – 670 K / LN2, LAr, 253 K – 373 K Yes Yes -

Gravimetric Measurements

The gravimetric gas sorption analyzer

has an ultrasensitive, temperaturecontrolled microbalance, providing

high-resolution and signal stability. The

instrument can measure adsorption isotherms in either static or flow mode.

* Equipped with mass spectrometer.

† Higher pressure measurements are possible for

single gas isotherms.

‡ Airless sample transfer capability.

Pore Size Analyzer

The low-pressure manometric gas

adsorption instrument measures surface area and pore size distributions,

and includes a 10 Pa transducer for

high- resolution micropore analysis.

Multicomponent Gas Measurements

The combined gravimetric/manometric

instrument can measure sorption

isotherms of binary gas mixtures. A

second manometric instrument,

equipped with a gas chromatograph,

can measure adsorption isotherms for

multicomponent gases.

Multicomponent Gas Measurements. Instrument for 

binary gas mixtures (bottom right) and manometric

instrument with gas chromatography for multicomponent 

gas measurements (upper left).

Continuously vented cabinets for hydrogen and methane 

gas cylinders

Binary Gas Adsorption Measurements. A magnetic 

suspension balance monitors mass uptake

simultaneously with changes to the total pressure.

“Vapor‐ and liquid‐phase adsorption of alcohol and water in silicalite‐1 synthesized in 

fluoride media” R.F. DeJaco et al. AIChE J. 66, e16868 (2020).

“Understanding material characteristics through signature traits from He pycnometry” 

H.G.T. Nguyen et al. Langmuir 35, 2115 (2019).

"A reference high-pressure CO2adsorption isotherm for ammonium ZSM-5 zeolite: 

Results of an interlaboratory study” H.G.T. Nguyen et al. Adsorption 24, 531 (2018).

"Experimental aspects of buoyancy correction in measuring reliable high-pressure 

excess adsorption isotherms using the gravimetric method” H.G.T. Nguyen et al. 

Meas. Sci. Technol. 28, 125802 (2017).

Select Publications

Contact:

Giang Nguyen

301-975-2600

huong.nguyen@nist.gov

Roger van Zee

301-975-2363

roger.vanzee@nist.gov

adsorption.nist.gov