ASTM D3766-24

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Designation: D3766 − 08 (Reapproved 2018) D3766 − 24
Standard Terminology Relating to
1
Catalysts and Catalysis
This standard is issued under the fixed designation D3766; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This terminology covers definitions of terms related to catalysts and catalysis.
NOTE 1—The Manual of Symbols and Terminology for Physicochemical Quantities and Units presents authoritative descriptions of many terms used in
2
the field of catalysis.
1.2 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Terminology
2.1 Definitions:
abrasion, n—the gradual removal of material from a surface due to friction typically generating fine particles. Note: abrasion
and attrition are often used interchangeably.
activity, n—of a catalyst, the measure of the rate of a specific catalytic reaction conducted in the presence of a catalyst.
attrition, n—the wearing down of particles by grinding against each other producing chips and fine particles. Note: abrasion
and attrition are often used interchangeably.
calcine, v—in catalysis, to heat a material to a high temperature causing a physical or chemical change, for example, loss of
moisture and volatile matter, or a phase change, or both.
catalyst bed support, n—an essentially inert plate, grid, particulate bed, or other structural component designed to hold up or
bear a quantity of catalyst in a catalytic reactor.
catalyst carrier, n—a solid, generally porous material upon the surface or into the voids of which catalytic materials are placed
to create the desired catalyst.
DISCUSSION—
A carrier may have or contribute to catalytic activity.
1
This terminology is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.92 on Nomenclature and
Definitions.
Current edition approved Nov. 1, 2018Jan. 1, 2024. Published December 2018January 2024. Originally approved in 1979. Last previous edition approved in 20132018
as D3766–08(2013).D3766 – 08 (2018). DOI: 10.1520/D3766-08R18.10.1520/D3766-24.
2
“The Manual of Symbols and Terminology for Physicochemical Quantities and Units—Appendix II. Definitions, Terminology and Symbols in Colloid and Surface
Chemistry. Part II: Heterogeneous Catalysis,” Pure and Applied Chemistry, Vol 46, No. 1, 73–90(1976).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D3766 − 24
catalyst substrate,n—less preferred alternative term for catalyst carrier.
catalyst support,n—less preferred alternative term for catalyst carrier.
crush strength, n—in catalysis, a measure of the resistance of formed catalysts or catalyst carriers, either singly or in bulk, to
...

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Designation: D3766 − 24
Standard Terminology Relating to
1
Catalysts and Catalysis
This standard is issued under the fixed designation D3766; 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 (´) indicates an editorial change since the last revision or reapproval.
DISCUSSION—A carrier may have or contribute to catalytic activity.
1. Scope
1.1 This terminology covers definitions of terms related to
catalyst substrate, n—less preferred alternative term for cata-
catalysts and catalysis.
lyst carrier.
NOTE 1—The Manual of Symbols and Terminology for Physicochemi-
catalyst support, n—less preferred alternative term for catalyst
cal Quantities and Units presents authoritative descriptions of many terms
2 carrier.
used in the field of catalysis.
1.2 This international standard was developed in accor-
crush strength, n—in catalysis, a measure of the resistance of
dance with internationally recognized principles on standard-
formed catalysts or catalyst carriers, either singly or in bulk,
ization established in the Decision on Principles for the
to loss of form when subjected to a compressive force.
Development of International Standards, Guides and Recom-
DISCUSSION—Formed catalysts may include tablets, spheres,
mendations issued by the World Trade Organization Technical extrudates, rings, pellets, etc. and should be distinguished from
powders and granules.
Barriers to Trade (TBT) Committee.
density, packing (bulk), n—the ratio of the mass of a
2. Terminology
collection of discrete pieces of solid material to the sum of
2.1 Definitions:
the volumes of: the solids in each piece, the voids within the
abrasion, n—the gradual removal of material from a surface
pieces, and the voids among the pieces of the particular
due to friction typically generating fine particles. Note:
collection.
abrasion and attrition are often used interchangeably.
density, particle (envelope), n—the ratio of the mass of a
activity, n—of a catalyst, the measure of the rate of a specific
particle to the sum of the volumes of: the solid in each piece
catalytic reaction conducted in the presence of a catalyst.
and the voids within each piece, that is, within close-fitting
attrition, n—the wearing down of particles by grinding against
imaginary envelopes completely surrounding each piece.
each other producing chips and fine particles. Note: abra-
density, skeletal, n—the ratio of the mass of discrete pieces of
sion and attrition are often used interchangeably.
solid material to the sum of the volumes of: the solid
calcine, v—in catalysis, to heat a material to a high temperature
material in the pieces and closed (or blind) pores within the
causing a physical or chemical change, for example, loss of
pieces.
moisture and volatile matter, or a phase change, or both.
density, theoretical, n—the ratio of the mass of a collection of
catalyst bed support, n—an essentially inert plate, grid,
discrete pieces of solid material to the sum of the volumes of
particulate bed, or other structural component designed to
said pieces, the solid material having an ideal regular
hold up or bear a quantity of catalyst in a catalytic reactor.
arrangement at the atomic level.
...