ASTM D6761-02

Standard Test Method for Determination of the Total Pore Volume of Catalysts and Catalyst Carriers

SCOPE
1.1 This test method covers the determination of the total pore volume of catalysts and catalyst carriers, that is, the volume of pores having pore diameter between approximately 14 m and 0.4 to 0.6 nm (4 to 6 Å).
1.2 This test method involves hazardous materials, operations and equipment. 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 to determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 8, 9.1.7, and 9.1.11.

General Information

• Status: Historical
• Publication Date: 09-Feb-2002
• ICS: 71.040.30 - Chemical reagents
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.02 - Physical-Mechanical Properties

Relations

• Replaced By: ASTM D6761-04 - Standard Test Method for Determination of the Total Pore Volume of Catalysts and Catalyst Carriers
• Effective Date: 01-Jul-2004
• Referred By: ASTM D8413-22 - Standard Guide for Measuring the Water Pore Volume of Catalytic Materials by Centrifuge
• Effective Date: 10-Feb-2002
• Referred By: ASTM D8325-20 - Standard Guide for Evaluation of Nuclear Graphite Surface Area and Porosity by Gas Adsorption Measurements
• Effective Date: 10-Feb-2002

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 6761 – 02
Standard Test Method for
Determination of the Total Pore Volume of Catalysts and
Catalyst Carriers
This standard is issued under the fixed designation D 6761; 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.
1. Scope
W = weight of sample,
W = weight of sealed empty sample cell,
1.1 This test method covers the determination of the total
c
W8 = weight of sealed sample cell filled with mercury,
pore volume of catalysts and catalyst carriers, that is, the C
W = weight of sealed sample cell with sample,
s
volume of pores having pore diameter between approximately
W8 = weight of sealed sample cell with sample filled
S
14 μm and 0.4 to 0.6 nm (4 to 6 Å).
with mercury,
1.2 This test method involves hazardous materials, opera-
C
= volume of mercury in empty sample cell (volume
V
Hg
tions and equipment. This standard does not purport to address
of sample cell),
all of the safety concerns, if any, associated with its use. It is
S
= volume of mercury in cell with sample,
V
Hg
the responsibility of the user of this standard to establish
Hg 3
= sample volume, cm ,
V
S
appropriate safety and health practices and to determine the
V = specific sample volume,
Hg
applicability of regulatory limitations prior to use. Specific
V = particle volume,
P
hazard statements are given in Section 8, 9.1.7, and 9.1.11.
D = particle density,
P
W = weight mercury reservoir after filling buret with
b
2. Referenced Documents
sample.
2.1 ASTM Standards:
3.2.2 For Helium Pycnometry:
D 3766 Terminology Relating to Catalysts and Catalysis
E 177 Practice for Use of the Terms Precision and Bias in
3 3
ASTM Test Methods V = volume of sample cell and associated tubing, cm ,
C
E 456 Terminology Relating to Quality and Statistics V = reference volume, cm ,
R
He
= sample volume, cm ,
E 691 Practice for Conducting an Interlaboratory Study to V
S
V = volume of calibration cylinder, cm ,
Determine the Precision of a Test Method
Cyl
V = volume of calibration standard, cm ,
STD
3. Terminology
V = specific sample volume,
He
P8 = pressure in empty sample cell, psig or Pascals,
3.1 Definitions:
P8 = pressure in empty sample cell, after the reference
3.1.1 particle volume—the volume of a particle including
volume has been included in the system, psig or
pores into which mercury cannot penetrate at ambient pressure
Pascals,
(smaller than approximately 14 μm diameter pore mouth).
P = pressure in sample cell with sample or calibration
3.1.2 true volume—the volume of a particle, including
standard before the reference volume has been
pores, into which helium cannot penetrate (smaller than about
included in the system, psig or Pascals,
approximately 4 to 6 Å diameter pore mouth).
P = pressure with sample or calibration standard in
3.1.3 Other definitions and terms used in this test method
the sample cell, after the reference volume has
are defined in Terminology D 3766.
been included in the system, psig or Pascals,
3.2 Symbols:
W = tare weight of sample cup, g,
3.2.1 For Mercury Intrusion:
W = weight of sample + tare weight of sample cup, g,
W = weight of sample, g,
D = true density,
t
P.V. = pore volume.
This test method is under the jurisdiction of ASTM Committee D32 on
4. Summary of Test Method
Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-
4.1 The total pore volume of a catalyst or catalyst carrier is
Mechanical Properties.
Current edition approved Feb. 10, 2002. Published May 2002. determined as the difference between the particle volume and
Annual Book of ASTM Standards, Vol 05.05.
the true volume, measured by mercury intrusion and helium
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.
D 6761
pycnometry, respectively. The particle volume is determined
by mercury intrusion at ambient pressure and the true volume
is determined by helium displacement at pressures above
ambient.
5. Significance and Use
5.1 This test method provides for the measurement of
volume of pores that are in the range of catalytic importance
and possibly for adsorption processes.
6. Apparatus
6.1 For Mercury Intrusion:
6.1.1 Chamber, capable of holding the sample cell (com-
monly referred to as a penetrometer), which contains the
sample. This chamber must be capable of being evacuated and
contain enough mercury to fill the penetrometer.
6.1.2 Glass Sample Cell (penetrometer), having a wide base
and narrow bore stem. If the sample is powder, the penetrom-
eter should have a provision in the base to prevent fine particles
from passing into the stem when the cell is evacuated. The
penetrometer must have the capability of being sealed.
6.1.3 Vacuum Pump, capable of attaining pressures of less
than 0.05 torr.
6.1.4 Valve, for choosing vacuum and vent, for evacuation
of the sample cell and filling the sample cell, respectively. FIG. 1 Schematic Diagram of Burette
6.1.5 Valve, for rapid evacuation or venting of the system.
6.1.6 Valve, for controlled evacuation or venting.
6.3 For Helium Pycnometry—A schematic diagram of the
6.1.7 A method or device to prevent mercury vapor from
pycnometer apparatus is shown in Fig. 2. It should be con-
being vented into the room through the vacuum pump and to
structed from metal and have the following features:
prevent contaminants from entering the vacuum pump.
6.3.1 Sample Cell, having a volume suitable for the desired
6.1.8 Pressure-Measuring Device, capable of reading in the
sample size and calibrated to the nearest 0.1 cm . This volume
range 0 to 1000 torr or higher.
is indicated in Fig. 2.
6.1.9 Balance, measuring to the nearest 1 mg (60.001 g).
6.3.2 Reference Volume (V ), a precisely calibrated volume
R
6.2 For Mercury Intrusion with a Burette—A schematic
known to the nearest 0.02 cm .
diagram of the burette is shown in Fig. 1. It has the following
6.3.3 Pressure Transducer, (0 to 25 psig or 0 to 172.3 kPa)
features:
with minimum volume displacement and linear within 0.1 %.
6.2.1 Glass Sample Cell, with a needle valve suitable for
6.3.4 Pressure Relief Valve, set to 25 psig (172.3 kPa), to
handling mercury. The tip, which is submerged in the mercury
avoid overpressurization of the transducer.
reservoir, should be narrow enough so as to prevent drops of
6.3.5 Filter, to prevent powder from contaminating the
mercury from becoming lost if the reservoir is removed for
pressure transducer.
weighing.
6.3.6 Input Flow Control Valves, to control pressurization.
6.2.2 Burette, a calibrated narrow bore tube ending in a
6.3.7 Output Flow Control Valves, to vent the gas.
curved tip in the sample cell to prevent fine particles from
6.3.8 Valve, to connect the reference volume to the sample
passing into the burette. There is a clear mark on the burette at
cell.
23 cm above the curved tip.
6.3.9 Non-Porous Calibration Standard, (preferably stain-
6.2.3 Manifold, with a splash bulb and appropriate needle 1 2
less steel) of known volume which fills ⁄4 to ⁄3 of the sample
valves for choosing either vacuum or vent.
cup.
6.2.4 Mercury Reservoir with Lid, capable of containing the
amount of mercury necessary to fill the sample cell and burette
while the tip of the sample cell valve is still submerged in
mercury. A weighing bottle of 5 cm diameter and 3 cm height
is suitable.
6.2.5 Vacuum Pump, capable of attaining pressures of 0.05
torr.
6.2.6 Cold Trap, to prevent mercury vapor from being
vented into the laboratory and to prevent contaminants from
entering the vacuum pump. FIG. 2 Pycnometer Apparatus
D 6761
6.3.10 Digital Meter, for reading the pressure to 0.001 psig 9.1.11 When the low pressure run is complete, bring the low
(6.89 Pa) from the transducer. pressure chamber back to atmospheric pressure and follow the
6.3.11 Sample Cell Cover, with O-ring seal. manufacturer’s recommendations for removing the penetrom-
eter from the low pressure port. (Warning—As the penetrom-
7. Reagents
eter is removed from the low pressure port, be sure to tilt the
7.1 For Mercury Instrusion:
bulb end of the penetrometer down and the stem end up, so
7.1.1 Mercury, triply distilled. mercury does not spill from the open stem end.)
7.2 For Helium Pycnometry:
9.1.12 Weigh the sealed penetrometer with sample and filled
7.2.1 Helium Gas, a cylinder of helium gas at least 99.9 %
with mercury using an analytical balance. Record this weight
pure, with regulator.
as (W8 ).
S
9.2 For Mercury Intrusion Using the Burette Method:
8. Hazards
9.2.1 Place a coolant (liquid nitrogen or dry ice-acetone
8.1 Samples that have been exposed to mercury are danger-
mixture) around the cold trap.
ous. Apply the precautions given by the following:
9.2.2 Close the vent valve (A) and the sample cell valve (C),
8.1.1 Mercury is a hazardous substance that can cause
and evacuate the burette by opening the vacuum valve (B).
illness and death. Mercury can also be absorbed through the
9.2.3 Slowly open the sample cell valve and allow mercury
skin; avoid direct contact.
to fill the sample cell and the burette. Clo
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