ISO/PRF TS 23362

TECHNICAL ISO/TS
SPECIFICATION 23362
First edition
Nanotechnologies — Nanostructured
porous alumina as catalyst support
for vehicle exhaust emission control
— Specification of characteristics and
measurement methods
Nanotechnologies — Alumine poreuse nanostructurée utilisée comme
support catalytique pour le contrôle des émissions d'échappement
des véhicules — Spécification des caractéristiques et méthodes de
mesurage
PROOF/ÉPREUVE
Reference number
ISO/TS 23362:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO/TS 23362:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms, definitions and abbreviated terms ................................................................................................................................ 1

3.1 Terms and definitions ....................................................................................................................................................................... 1

3.2 Abbreviated terms ............................................................................................................................................................................... 2

4 Characteristics and their measurement methods ............................................................................................................. 3

4.1 General ........................................................................................................................................................................................................... 3

4.2 Critical characteristics and their measurement methods ................................................................................. 3

4.3 Additional characteristics and their measurement methods ......................................................................... 3

5 Descriptions of characteristics and measurement methods .................................................................................. 3

5.1 General ........................................................................................................................................................................................................... 3

5.2 Specific surface area ........................................................................................................................................................................... 4

5.3 Specific pore volume .......................................................................................................................................................................... 4

5.4 Pore diameter ........................................................................................................................................................................................... 4

5.5 Impurity content ................................................................................................................................................................................... 4

5.6 Apparent density ................................................................................................................................................................................... 5

5.7 Tap density ................................................................................................................................................................................................. 5

5.8 Particle size ................................................................................................................................................................................................ 5

5.9 Loss on ignition ...................................................................................................................................................................................... 6

6 Reporting ...................................................................................................................................................................................................................... 6

Annex A (informative) Schematic illustration of three-way catalytic converter .....................................................7

Annex B (informative) Example of reporting table format ........................................................................................................... 8

Bibliography ................................................................................................................................................................................................................................ 9

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

Any trade name used in this document is information given for the convenience of users and does not

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO’s adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

Any feedback or questions on this document should be directed to the user’s national standards body. A

Nanostructured porous alumina for catalyst support of vehicle exhaust plays an important role in

automotive exhaust treatment . Three-way catalytic converters (TWCs) have been used in vehicle

exhaust control systems worldwide, which can convert carbon monoxide (CO), hydrocarbon (HC) and

oxynitride (NOx) into carbon dioxide (CO ), nitrogen (N ) and oxygen (O ). Nanostructured porous

alumina has the advantages of a high specific surface area (SSA) and excellent thermal stability, which

makes TWCs keep high catalytic activity at a temperature of 900 °C to 1 000 °C in gasoline cars. As

one of the most important materials in the catalytic converter , nanostructured porous alumina with

proper performance is in great demand. In the automotive exhaust treatment field, almost 11,000 tons

SSA, specific pore volume, impurities and thermal stability are the main characteristics affecting

the performance of nanostructured porous alumina as catalyst support . A high SSA can facilitate

homogeneous dispersion of noble metal. A suitable specific pore volume ensures efficient noble metal

loading and allows reaction gas to pass through and contact with the catalyst. Impurities can deactivate

the noble metal catalyst and thus are harmful. An excellent thermal stability guarantees that TWCs

maintain at high activity levels after a long distance running and thus have a prolonged service life. The

The world market demand for nanostructured porous alumina is growing year by year. Currently,

however, there are no standards for manufacturers in managing quality control and assurance, and for

This document provides characteristics and measurements of nanostructured porous alumina for

catalyst support of vehicle exhaust control. It aims to facilitate worldwide transactions between buyers

This document specifies characteristics to be measured of nanostructured porous alumina in powder

form for catalyst support of vehicle exhaust control and their relevant measurement methods. It

includes critical characteristics that are required to be measured and additional characteristics that are

recommended to be measured, based upon agreement between the interested parties. Measurement

This document is applicable to nanostructured porous alumina for gasoline-powered cars. It does not

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO/TS 80004-6, Nanotechnologies — Vocabulary — Part 6: Nano-object characterization

For the purposes of this document, the terms and definitions given in ISO/TS 80004-1, ISO/TS 80004-6

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

diameter of a pore in a model in which the pores typically are assumed to be cylindrical in shape and

dry mass per unit volume of a powder obtained by free pouring under specified conditions

[SOURCE: ISO 9161:2019, 3.1, modified — the admitted term “loose bulk density” has been deleted.]

dry mass per unit volume of a powder in a container that has been tapped under specified conditions

metallic or non-metallic element present in a material, but not intentionally added to the material

[SOURCE: ISO 3522:2007, 3.10, modified — “in a material, but not intentionally added to the material” has

replaced “but not intentionally added to a metal, and the minimum content of which is not controlled”.]

change in mass of a material held at a specified temperature, excluding the loss due to hygroscopic

[SOURCE: ISO 11323:2010, 8.4, modified — “a material held at a specified temperature” has replaced

fine ceramic body having multiple channels typically arranged in a honeycomb structure

Critical and additional characteristics to be measured of nanostructured porous alumina are listed in

Although the International Standards given in Table 1 and 2 are individually applicable to general or

specific materials, all the documents are not yet fully validated whether they are specifically applicable

to nanostructured porous alumina. Their application shall be validated and decided by the standards

As the nanostructured porous alumina is liable to adsorb moisture, its characteristics can be affected

by the storage conditions. The sample for measurements should be stored in a dry environment. If not,

the buyers and the sellers should agree upon the storage conditions of the samples for comparability of

The critical characteristics listed in Table 1 shall be measured. The measured values of these

characteristics shall be provided to the buyers during purchase. SSA and specific pore volume shall be