ASTM D4284-07
(Test Method)Standard Test Method for Determining Pore Volume Distribution of Catalysts by Mercury Intrusion Porosimetry
Standard Test Method for Determining Pore Volume Distribution of Catalysts by Mercury Intrusion Porosimetry
SIGNIFICANCE AND USE
This test method is intended to determine the volume distribution of pores in catalysts with respect to the apparent diameter of the entrances to the pores. In general, both the size and volume of pores in a catalyst affect its performance. Thus, the pore volume distribution is useful in understanding a catalyst’performance and in specifying a catalyst that can be expected to perform in a desired manner.
SCOPE
1.1 This test method covers the determination of the pore volume distributions of catalysts and catalyst supports by the method of mercury intrusion porosimetry. The range of apparent diameters of pores for which it is applicable is fixed by the operant pressure range of the testing instrument. This range is typically between apparent pore entrance diameters of about 100 and 0.003 m (3 nm).
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, 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. Specific hazard information is given in Section 8.
General Information
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Standards Content (Sample)
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Designation:D4284–07
Standard Test Method for
Determining Pore Volume Distribution of Catalysts by
1
Mercury Intrusion Porosimetry
This standard is issued under the fixed designation D4284; 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 3.1.3 intraparticle pores—those pores lying within the en-
velopesoftheindividualcatalystparticlesandthatareintruded
1.1 This test method covers the determination of the pore
during the test.
volume distributions of catalysts and catalyst supports by the
3.1.4 intruded pore volume—the volume of mercury that is
method of mercury intrusion porosimetry. The range of appar-
intruding into the pores during the test after this volume has
ent diameters of pores for which it is applicable is fixed by the
been corrected, if necessary, per 13.3.2.
operant pressure range of the testing instrument. This range is
typically between apparent pore entrance diameters of about
4. Summary of Test Method
100 and 0.003 µm (3 nm).
4.1 When a liquid does not wet a porous solid it will not
1.2 The values stated in SI units are to be regarded as
voluntarily enter the pores in the solid by capillary attraction.
standard. No other units of measurement are included in this
The nonwetting liquid (mercury in this test method) must be
standard.
forced into the pores by the application of external pressure.
1.3 This standard does not purport to address all of the
Thesizeoftheporesthatareintrudedisinverselyproportional
safety problems, if any, associated with its use. It is the
to the applied pressure. When a cylindrical pore model is
responsibility of the user of this standard to establish appro-
assumed, the relationship between pressure and size is:
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific hazard 24g~cosu!
d 5 (1)
P
information is given in Section 8.
where:
2. Referenced Documents
d = apparent diameter of the pore being intruded,
2
2.1 ASTM Standards:
g = surface tension of the mercury,
E177 Practice for Use of the Terms Precision and Bias in
u = contact angle between the mercury and the solid, and
ASTM Test Methods
P = absolute pressure causing the intrusion.
E456 Terminology Relating to Quality and Statistics
4.2 The volume of the intruded pores is determined by
E691 Practice for Conducting an Interlaboratory Study to
measuring the volume of mercury that is forced into them at
Determine the Precision of a Test Method
variouspressures.Asingle-poresizedistributiondetermination
involves increasing the pressure, either continuously or step-
3. Terminology
wise, and recording the measured intruded volume.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 apparent pore diameter—the diameter of a pore,
5. Significance and Use
assumed to be cylindrical, that is intruded at a pressure, P, and
5.1 This test method is intended to determine the volume
is calculated with Eq 1.
distribution of pores in catalysts with respect to the apparent
3.1.2 interparticle pores—those pores that occur between
diameteroftheentrancestothepores.Ingeneral,boththesize
particles when they are packed together and that are intruded
and volume of pores in a catalyst affect its performance.Thus,
during the test.
the pore volume distribution is useful in understanding a
catalyst’s performance and in specifying a catalyst that can be
1
This test method is under the jurisdiction of ASTM Committee D32 on
expected to perform in a desired manner.
Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-
Chemical Properties.
6. Limitations
Current edition approved April 1, 2007. Published April 2007. Originally
6.1 Mercury intrusion porosimetry, in common with many
approved in 1983. Last previous edition approved in 2003 as D4284–03. DOI:
10.1520/D4284-07.
other test methods, is only capable of sensing pores that are
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
opentotheoutsideofacatalystparticle,andwillnotdetermine
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
the volume of any pores that are completely enclosed by
Standards volume information, refer to the standard’s Document Summary page on
surrounding solid. Also, the test method will only determine
the ASTM website.
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D4284–07
the volume of intrudable pores that have an apparent diameter 8.1.3 Washhandsimmediatelyafteranyoperationinvolving
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