ASTM D4567-99

Standard Test Method for Single-Point Determination of Specific Surface Area of Catalysts and Catalyst Carriers Using Nitrogen Adsorption by Continuous Flow Method

SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m , where rapid surface area determinations are desired.  
1.2 Since the single-point method uses an approximation of the BET equation, the multipoint BET method (D3663) is preferred to the single-point method.  
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Apr-1999
• ICS: 71.040.30 - Chemical reagents
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.01 - Physical-Chemical Properties

Relations

• Replaced By: ASTM D4567-03 - Standard Test Method for Single-Point Determination of Specific Surface Area of Catalysts and Catalyst Carriers Using Nitrogen Adsorption by Continuous Flow Method
• Effective Date: 01-Oct-2003
• Referred By: ASTM D5675-13(2018) - Standard Classification for Low Molecular Weight PTFE and FEP Micronized Powders
• Effective Date: 10-Apr-1999

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4567 – 99
Standard Test Method for
Single-Point Determination of Specific Surface Area of
Catalysts and Catalyst Carriers Using Nitrogen Adsorption
by Continuous Flow Method
This standard is issued under the fixed designation D 4567; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
−20 2
1. Scope
A = cross-sectional area of nitrogen, 16.2 3 10 m .
cs
C = integrator counts.
1.1 This test method covers the single-point determination
I
T
C a = integrator counts corrected for ambient tempera-
I
of the surface area of catalysts and catalyst carriers that exhibit
ture.
Type II or Type IV nitrogen adsorption isotherms using a
P
C a = integrator counts corrected for ambient pressure.
I
nitrogen-helium flowing gas mixture. This test method is
N = Avogadro’s number, 6.02 3 10 , molecules/
applicable for the determination of total surface areas from 0.1
mole.
to 300 m , where rapid surface area determinations are desired.
P = partial pressure of nitrogen, torr.
1.2 Because the single-point method uses an approximation
P = ambient pressure, torr.
a
of the BET equation, the multipoint BET method (Test Method
P = saturated equilibrium vapor pressure of liquid
o
D 3663) is preferred to the single-point method.
nitrogen, torr.
NOTE 1—This is particularly true when testing microporous materials. R = gas constant, 82.1 cm atm/K mole.
T = ambient temperature, K.
a
1.3 This standard does not purport to address all of the
V = volume of nitrogen adsorbed at ambient tempera-
safety concerns, if any, associated with its use. It is the
ture and pressure, cm .
responsibility of whoever uses this standard to consult and
W = tare weight of sample cell, g.
establish appropriate safety and health practices and deter-
W = sample + tare weight of sample cell after analysis,
mine the applicability of regulatory limitations prior to use.
g.
W = weight of sample, g.
s
2. Referenced Documents
2.1 ASTM Standards:
4. Summary of Test Method
D 3663 Test Method for Surface Area of Catalysts
4.1 The sample is degassed by heating in a flow of inert gas
D 3766 Terminology Relating to Catalysts and Catalysis
to remove adsorbed vapors from the surface. The sample is
E 177 Practice for Use of the Terms Precision and Bias in
then immersed in a liquid nitrogen bath causing adsorption of
ASTM Test Methods
nitrogen from a flowing mixture of a fixed concentration of
E 456 Terminology Relating to Quality and Statistics
nitrogen in helium. When adsorption is complete, the sample is
E 691 Practice for Conducting an Interlaboratory Study to
allowed to warm to room temperature causing desorption,
Determine the Precision of a Test Method
which results in an increase in the nitrogen concentration in the
flowing mixture. The quantity of nitrogen gas desorbed is
3. Terminology
determined by sensing the change in thermal conductivity.
3.1 Definitions—Consult Terminology D 3766.
4.2 Calculation of the surface area is based on a modified
3.2 Symbols:Symbols:
form of the BET equation.
5. Significance and Use
5.1 This test method is useful for determining the specific
surface area of catalysts and catalyst carriers for material
This test method is under the jurisdiction of Committee D-32 on Catalysts and
specifications, manufacturing control, and research and devel-
is the direct responsibility of Subcommittee D32.01 on Physical Chemical Proper-
ties. opment in the evaluation of catalysts.
Current edition approved April 10, 1999. Published June 1999. Originally
published as D 4567 - 86. Last previous edition D 4567 - 86 (1994).
Annual Book of ASTM Standards, Vol 05.03.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D4567–99
FIG. 1 Apparatus
−7
6. Apparatus 6.4 Laboratory Balance with 0.1 mg (10 kg) sensitivity.
6.5 Gas-Tight Syringe or Gas Sampling Loop, 1.00 cm .
6.1 A schematic diagram of the apparatus is shown in Fig. 1.
The apparatus may be constructed of glass or metal tubing. It
7. Reagents
has the following features:
6.1.1 Differential Flow Controller from the gas inlet valve
7.1 Liquid Nitrogen of such purity that the saturated
to a flow control valve to eliminate fluctuations in the gas flow.
equilibrium vapor pressure is not more than 20 torr above
6.1.2 Two Thermal Conductivity Detectors— A reference
ambient pressure.
detector (A) to sense the nitrogen-helium gas mixture and a
7.2 Cylinder, with pressure regulator, of high purity 30
second detector (B) to sense changes in the gas mixture after
mole % nitrogen in helium equivalent to a relative pressure of
flowing through the sample cell. The two detectors are initially
approximately 0.3, where the nitrogen concentration is known
balanced to allow the detection of changes in the nitrogen
to within 0.1 mole %. Concentrations lower than 30 mole %
concentration.
should be used for materials containing micropores, for ex-
6.1.3 Flow-Through Sample Cells, of various volumes and
ample, zeolites.
shapes depending on the application.
6.1.4 Two Equilibration Tubes selected by a selector valve,
8. Calibration of the Apparatus
between the sample cell and detector (B). The small volume
8.1 If the gas mixture contains impurities, place a Dewar
tube has a volume of approximately 20 cm and the large
flask containing liquid nitrogen around the cold trap.
volume tube has a 100 cm capacity to allow for temperature
8.2 Using a gas-tight syringe inject 1.00 cm (or some other
and pressure equilibration of a wide range of volumes of gases.
known volume) of air or nitrogen into the calibration septum.
6.1.5 Flow Meter, to monitor the flow rate of the nitrogen-
The digital integrator should display 2.84 6 0.03 counts (see
helium mixture maintained at approximately 20 cm /min.
11.3) for a 1.00-cm injection (or a proportional number of
6.1.6 Diffusion Baffle, to prevent air from diffusing back into
counts for a different volume). If the counts are greater than
the system during cooling of the sample.
2.84, increase the gas flow through the flow control valve. If
6.1.7 Bridge Balance Meter, to display balance or imbal-
the counts are less than 2.84, decrease the gas flow and retest.
ance between detectors A and B.
6.1.8 Digital Integrator, to measure the imbalance between
9. Preparation of Sample
detectors A and B and display the surface area of the sample.
9.1 Weigh to 0.0001 g a clean, dry empty sample cell.
6.1.9 Septum or Fixed Loop, for injection of calibration gas.
Record the weight, W .
6.1.10 Degassing Station, for removal of adsorbed vapors 1
9.2 Place the catalys
...