ASTM D4222-03

Standard Test Method for Determination of Nitrogen Adsorption and Desorption Isotherms of Catalysts By Static Volumetric Measurements

SIGNIFICANCE AND USE
The test method has two main functions: first, it provides data useful for establishing the pore size distribution of catalyst materials, which in turn may influence their performance; and second, it serves as a laboratory test which may be used to study porosity changes that may occur during the manufacture and evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen. A static volumetric measuring system is used to obtain sufficient equilibrium adsorption points on each branch of the isotherm to adequately define the adsorption and desorption branches of the isotherm. Thirty points evenly spread over the isotherm is considered to be the minimum number of points that will adequately define the isotherm.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2003
• ICS: 17.060 - Measurement of volume, mass, density, viscosity
• ICS: 71.040.30 - Chemical reagents
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.01 - Physical-Chemical Properties

Relations

• Replaces: ASTM D4222-98 - Standard Test Method for Determination of Nitrogen Adsorption and Desorption Isotherms of Catalysts By Static Volumetric Measurements
• Effective Date: 01-Oct-2003
• Replaced By: ASTM D4222-03(2008) - Standard Test Method for Determination of Nitrogen Adsorption and Desorption Isotherms of Catalysts and Catalyst Carriers by Static Volumetric Measurements
• Effective Date: 01-Apr-2008
• Referred By: ASTM D4641-17 - Standard Practice for Calculation of Pore Size Distributions of Catalysts and Catalyst Carriers from Nitrogen Desorption Isotherms
• Effective Date: 01-Oct-2003
• Referred By: ASTM D8325-20 - Standard Guide for Evaluation of Nuclear Graphite Surface Area and Porosity by Gas Adsorption Measurements
• Effective Date: 01-Oct-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4222–03
Standard Test Method for
Determination of Nitrogen Adsorption and Desorption
Isotherms of Catalysts and Catalyst Carriers by Static
1
Volumetric Measurements
This standard is issued under the fixed designation D4222; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
PH = initial helium pressure, torr.
1.1 This test method covers the determination of nitrogen
1
PH = helium pressure after equilibration, torr.
2
adsorption and desorption isotherms of catalysts and catalyst
2
TH = temperature of manifold at initial helium pressure,
1
carriers at the boiling point of liquid nitrogen. A static
°C.
volumetric measuring system is used to obtain sufficient
TH = temperature of manifold after equilibration, °C.
2
equilibriumadsorptionpointsoneachbranchoftheisothermto
P = initial N pressure, torr.
1 2
adequately define the adsorption and desorption branches of
T = manifold temperature at initial N pressure, K.
1 2
the isotherm. Thirty points evenly spread over the isotherm is
T8 = manifold temperature at initial N pressure, °C.
1 2
considered to be the minimum number of points that will
P = pressure after equilibration, torr.
2
adequately define the isotherm.
T = manifold temperature after equilibrrium, K.
2
1.2 The values stated in SI units are to be regarded as the
T8 = manifold temperature after equilibrium, °C.
2
standard. The values given in parentheses are for information
P = initial N pressure during desorption, torr.
3 2
only.
T = manifold temperature at initial N pressure, K.
3 2
1.3 This standard does not purport to address all of the
T8 = manifold temperature at initial N pressure, °C.
3 2
safety concerns, if any, associated with its use. It is the P = pressure after equilibration during desorption, torr.
4
T = manifold temperature after equilibration, K.
responsibility of the user of this standard to establish appro-
4
T8 = manifold temperature after equilibration, °C.
priate safety and health practices and determine the applica-
4
P = liquid nitrogen vapor pressure, torr.
bility of regulatory limitations prior to use. 0
T = liquid nitrogen temperature, K.
s
2. Referenced Documents X = relative pressure, P /P .
2(4) 0
3
3 V = volume of manifold, cm .
d
2.1 ASTM Standards:
3
V = the dead-space volume factor, cm (STP)/torr.
s
D3663 Test Method for Surface Area of Catalysts
W = mass of sample, g.
s
D3766 Terminology Relating to Catalysts and Catalysis
W = tare of sample tube, g.
1
E177 Practice for Use of the Terms Precision and Bias in
W8 = sample mass + tare of tube after degassing, g.
2
ASTM Test Methods
W = sample mass + tare of tube after adsorption, g.
2
3
E456 Terminology Relating to Quality and Statistics
V = volume of nitrogen in the dead-space, cm (STP).
ds
E691 Practice for Conducting an Interlaboratory Study to
V = see 12.4.3.
1
Determine the Precision of a Test Method
V = see 12.4.4.
2
V = see 12.4.5.
t
3. Terminology
V = see 12.4.7.
ad
3.1 Definitions—See Terminology D3766. V = see 12.5.
de
3.2 Symbols:
4. Summary of Test Method
4.1 Thesampleisheatedandevacuatedtoremoveadsorbed
1
ThistestisunderthejurisdictionofASTMCommitteeD32onCatalystsandis
vapors from the surface.The nitrogen adsorption branch of the
the direct responsibility of Subcommittee D32.01 on Physical-Chemical Properties.
isotherm is determined by evacuating the sample, cooling the
Current edition approved Oct. 1, 2003. Published October 2003. Originally
sample to the boiling point of liquid nitrogen (;77.3 K), and
approved in 1983. Last previous edition approved in 1998 as D4222–98.
2
Adamson,A.W., Physical Chemistry of Surfaces, 3rd ed., JohnWiley & Sons,
subsequently adding stepwise, known amounts of nitrogen gas
New York, NY, 1976, p. 532.
to the sample in such amounts that the form of the adsorption
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
isotherm is adequately defined and the saturation pressure of
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on nitrogen is reached. Each additional dose of nitrogen is
the ASTM website.
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1

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D4222–03
6.1.4 Value (H), from the helium supply to the distribution
manifold.
6.1.5 Valve (N), from the nitrogen supply to the distribution
manifold.
6.1.6 The connection between the sample tube and the S
valve can be a standard-taper glass joint, a glass-to-glass seal,
o
...