ASTM D4567-03(2008)
(Test Method)Standard Test Method for Single-Point Determination of Specific Surface Area of Catalysts and Catalyst Carriers Using Nitrogen Adsorption by Continuous Flow Method
Standard Test Method for Single-Point Determination of Specific Surface Area of Catalysts and Catalyst Carriers Using Nitrogen Adsorption by Continuous Flow Method
SIGNIFICANCE AND USE
This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.
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 m2, where rapid surface area determinations are desired.
1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D 3663) is preferred to the single-point method.
Note 1—This is particularly true when testing microporous materials.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, 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.
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Designation:D4567 −03(Reapproved 2008)
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 D4567; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the single-point determination
3.1 Definitions—See Terminology D3766.
ofthesurfaceareaofcatalystsandcatalystcarriersthatexhibit
3.2 Symbols:
Type II or Type IV nitrogen adsorption isotherms using a
nitrogen-helium flowing gas mixture. This test method is
−20 2
applicable for the determination of total surface areas from 0.1
A = cross-sectional area of nitrogen, 16.2×10 m .
cs
to300m ,whererapidsurfaceareadeterminationsaredesired.
C = integrator counts.
I
T
C a = integrator counts corrected for ambient temperature.
1.2 Because the single-point method uses an approximation I
P
C a = integrator counts corrected for ambient pressure.
I
oftheBETequation,themultipointBETmethod(TestMethod
N = Avogadro’s number, 6.02×10 , molecules/mole.
D3663) is preferred to the single-point method.
P = partial pressure of nitrogen, torr.
NOTE 1—This is particularly true when testing microporous materials. P = ambient pressure, torr.
a
P = saturated equilibrium vapor pressure of liquid
o
1.3 The values stated in SI units are to be regarded as
nitrogen, torr.
standard. No other units of measurement are included in this
R = gas constant, 82.1 cm atm/K mole.
standard.
T = ambient temperature, K.
a
1.4 This standard does not purport to address all of the
V = volume of nitrogen adsorbed at ambient temperature
safety concerns, if any, associated with its use. It is the
and pressure, cm .
responsibility of whoever uses this standard to consult and
W = tare of sample cell, g.
establish appropriate safety and health practices and deter-
W = sample mass+tare of sample cell after analysis, g.
mine the applicability of regulatory limitations prior to use.
W = mass of sample, g.
s
2. Referenced Documents
4. Summary of Test Method
2.1 ASTM Standards:
4.1 Thesampleisdegassedbyheatinginaflowof inertgas
D3663Test Method for Surface Area of Catalysts and
to remove adsorbed vapors from the surface. The sample is
Catalyst Carriers
then immersed in a liquid nitrogen bath causing adsorption of
D3766Terminology Relating to Catalysts and Catalysis
nitrogen from a flowing mixture of a fixed concentration of
E177Practice for Use of the Terms Precision and Bias in
nitrogeninhelium.Whenadsorptioniscomplete,thesampleis
ASTM Test Methods
allowed to warm to room temperature causing desorption,
E456Terminology Relating to Quality and Statistics
whichresultsinanincreaseinthenitrogenconcentrationinthe
E691Practice for Conducting an Interlaboratory Study to
flowing mixture. The quantity of nitrogen gas desorbed is
Determine the Precision of a Test Method
determined by sensing the change in thermal conductivity.
4.2 Calculation of the surface area is based on a modified
This test method is under the jurisdiction of Committee D32 on Catalysts and
form of the BET equation.
is the direct responsibility of Subcommittee D32.01 on Physical-Chemical Proper-
ties.
Current edition approved April 1, 2008. Published April 2008. Originally
5. Significance and Use
approved in 1986. Last previous edition approved in 2003 as D4567–03. DOI:
10.1520/D4567-03R08.
5.1 This test method is useful for determining the specific
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
surface area of catalysts and catalyst carriers for material
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
specifications, manufacturing control, and research and devel-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. opment in the evaluation of catalysts.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4567−03 (2008)
FIG. 1 Apparatus
6. Apparatus 6.3 Dewar Flasks.
−7
6.1 AschematicdiagramoftheapparatusisshowninFig.1. 6.4 Laboratory Balance with 0.1 mg (10 kg) sensitivity.
The apparatus may be constructed of glass or metal tubing. It 3
6.5 Gas-Tight Syringe or Gas Sampling Loop, 1.00 cm .
has the following features:
6.1.1 Differential Flow Controller from the gas inlet valve
7. Reagents
toaflowcontrolvalvetoeliminatefluctuationsinthegasflow.
7.1 Liquid Nitrogen, of such purity that the saturated equi-
6.1.2 Two Thermal Conductivity Detectors—A reference
librium vapor pressure is not more than 20 torr above ambient
detector (A) to sense the nitrogen-helium gas mixture and a
pressure.
second detector (B) to sense changes in the gas mixture after
7.2 Cylinder, with pressure regulator, of high purity 30
flowingthroughthesamplecell.Thetwodetectorsareinitially
mole% nitrogen in helium equivalent to a relative pressure of
balanced to allow the detection of changes in the nitrogen
approximately 0.3, where the nitrogen concentration is known
concentration.
to within 0.1 mole%. Concentrations lower than 30 mole%
6.1.3 Flow-Through Sample Cells, of various volumes and
should be used for materials containing micropores, for
shapes depending on the application.
example, zeolites.
6.1.4 Two Equilibration Tubes selected by a selector valve,
between the sample cell and detector (B). The small volume
8. Calibration of the Apparatus
tube has a volume of approximately 20 cm and the large
8.1 If the gas mixture contains impurities, place a Dewar
volume tube has a 100 cm capacity to allow for temperature
flask containing liquid nitrogen around the cold trap.
andpressureequilibrationofawiderangeofvolumesofgases.
6.1.5 Flow Meter, to monitor the flow rate of the nitrogen-
8.2 Usingagas-tightsyringeinject1.00cm (orsomeother
helium mixture maintained at approximately 20 cm /min.
known volume) of air or nitrogen into the calibration septum.
6.1.6 Diffusion Baffle,topreventairfromdiffusingbackinto
The digital integrator should display 2.84 6 0.03 counts (see
the system during cooling of the sample.
11.3) for a 1.00-cm injection (or a proportional number of
6.1.7 BridgeBalanceMeter,todisplaybalanceorimbalance
counts for a different volume). If the counts are greater than
between detectors A and B.
2.84, increase the gas flow through the flow control valve. If
6.1.8 Digital Integrator, to measure the imbalance between
the counts are less than 2.84, decrease the gas flow and retest.
detectors A and B and display the surface area of the sample.
6.1.9 Septum or Fixed Loop,forinjectionofcalibrationgas. 9. Preparation of Sample
6.1.10 Degassing Station, for removal of adsorbed vapors
9.1 Weigh to
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D4567–99 Designation: D 4567 – 03 (Reapproved 2008)
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 D4567; 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
1.1 Thistestmethodcoversthesingle-pointdeterminationofthesurfaceareaofcatalystsandcatalystcarriersthatexhibitType
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 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method
D3663) is preferred to the single-point method.
NOTE 1—This is particularly true when testing microporous materials.
1.3
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, 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.
2. Referenced Documents
2.1 ASTM Standards:
D3663 Test Method for Surface Area of Catalysts and Catalyst Carriers
D3766 Terminology Relating to Catalysts and Catalysis
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions—Consult—See Terminology D3766.
3.2 Symbols:Symbols: Symbols:
−20 2
A = cross-sectional area of nitrogen, 16.2 310 m .
cs
C = integrator counts.
I
T
C a = integrator counts corrected for ambient temperature.
I
P
C a = integrator counts corrected for ambient pressure.
I
N = Avogadro’s number, 6.02 310 , molecules/mole.
P = partial pressure of nitrogen, torr.
P = ambient pressure, torr.
a
P = saturated equilibrium vapor pressure of liquid nitrogen, torr.
o
R = gas constant, 82.1 cm atm/K mole.
T = ambient temperature, K.
a
This test method is under the jurisdiction of Committee D-32 on Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical Chemical Properties.
Current edition approved April 10, 1999. Published June 1999. Originally published as D 4567 - 86. Last previous edition D 4567 - 86 (1994).
This test method is under the jurisdiction of Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-Chemical Properties.
Current edition approved April 1, 2008. Published April 2008. Originally approved in 1986. Last previous edition approved in 2003 as D4567–03.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
, Vol 05.03.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4567 – 03 (2008)
V = volume of nitrogen adsorbed at ambient temperature and pressure, cm .
W = tare weight of sample cell, g.
W = sample+tare weightsample mass+tare of sample cell after analysis, g.
W = weightmass of sample, g.
s
4. Summary of Test Method
4.1 The sample is degassed by heating in a flow of inert gas to remove adsorbed vapors from the surface. The sample is then
immersed in a liquid nitrogen bath causing adsorption of nitrogen from a flowing mixture of a fixed concentration of nitrogen in
helium.When adsorption is complete, the sample is allowed to warm to room temperature causing desorption, which results in an
increase in the nitrogen concentration in the flowing mixture. The quantity of nitrogen gas desorbed is determined by sensing the
change in thermal conductivity.
4.2 Calculation of the surface area is based on a modified 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
specifications, manufacturing control, and research and development in the evaluation of catalysts.
6. Apparatus
6.1 Aschematic diagram of the apparatus is shown in Fig. 1.The apparatus may be constructed of glass or metal tubing. It has
the following features:
6.1.1 Differential Flow Controller from the gas inlet valve to a flow control valve to eliminate fluctuations in the gas flow.
6.1.2 Two Thermal Conductivity Detectors— A reference detector (A) to sense the nitrogen-helium gas mixture and a second
detector (B) to sense changes in the gas mixture after flowing through the sample cell. The two detectors are initially balanced to
allow the detection of changes in the nitrogen concentration.
6.1.3 Flow-Through Sample Cells, of various volumes and shapes depending on the application.
6.1.4 Two Equilibration Tubes selected by a selector valve, between the sample cell and detector (B). The small volume tube
3 3
has a volume of approximately 20 cm and the large volume tube has a 100 cm capacity to allow for temperature and pressure
equilibration of a wide range of volumes of gases.
6.1.5 Flow Meter, to monitor the flow rate of the nitrogen-helium mixture maintained at approximately 20 cm /min.
6.1.6 Diffusion Baffle, to prevent air from diffusing back into the system during cooling of the sample.
6.1.7 Bridge Balance Meter, to display balance or imbalance between detectors A and B.
6.1.8 Digital Integrator, to measure the imbalance between detectors A and B and display the surface area of the sample.
6.1.9 Septum or Fixed Loop, for injection of calibration gas.
6.1.10 Degassing Station, for removal of adsorbed vapors from the sample.
6.1.11 Cold Trap, for removal of impurities in the gas mixture.
6.1.12 Thermal Equilibration Tube , to allow the flowing gas mixture to reach temperature and pressure equilibration before
reaching detector (A).
FIG. 1 Apparatus
D 4567 – 03 (2008)
6.2 Heating Mantle.
6.3 Dewar Flasks.
−7
6.4 Laboratory Balance with 0.1 mg (10 kg) sensitivity.
6.5 Gas-Tight Syringe or Gas Sampling Loop, 1.00 cm .
7. Reagents
7.1 Liquid Nitrogen, of such purity that the saturated equilibrium vapor pressure is not more than 20 torr above ambient
pressure.
7.2 Cylinder, with pressure regulator, of high purity 30 mole% nitrogen in helium equivalent to a relative pressure of
approximately0.3,wherethenitrogenconcentrationisknowntowithin0.1mole%.Concentrationslowerthan30mole%should
be used for materials containing micropores, for
...
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