BS 4359-4:1995

Committees responsible
Foreword
Recommendations
Introduction
1 Scope
2 References
3 Definitions
4 Principles
5 Sample preparation
6 Volumetric method
7 Flow methods
8 Calculation of the metal surface area
9 Reporting of results
Annex
A (informative) Modification of method for other metals
Tables
1 Stoichiometry values recommended for use in
   calculations
2 Values for surface density of metal atoms recommended
   for use in calculations
Figures
1 Typical apparatus for the volumetric method
2 Typical adsorption isotherm for hydrogen on platinum
   (linear scales)
3 Typical linearized plot of adsorption against
   pressure (linear scales)
4 Typical apparatus for the flow methods
5 Schematic TCD response in pulsed flow
6 Schematic TCD response in continuous flow
List of references

Describes recommended methods for the determination of metal surface area using gas adsorption. Coverage includes: sample preparation, volumetric method, flow methods, and calculation of the metal surface area. Also gives definitions, tables and diagrams.

This Part of BS 4359 describes recommended methods for the determination of metal surface area using gas adsorption. They are suitable for supported monometallic catalysts where the metal surface area differs from the total surface area. These methods may also be suitable for other metal catalysts, such as some Raney materials. Specific recommendations are given for the determination of metal surface area of nickel, palladium, platinum and copper. Information on the extension of these methods to other metals in Groups VIII and IB of the periodic table is given in Annex A.

Recommendations are made regarding the most suitable gas and test methods for a given metal/support combination.

Both chemisorption methods and those which employ surface reaction (or titration) are described.

Volumetric or flow techniques may be used to determine the amount of gas chemisorbed.

Recommendations are given to correct for any reversible adsorption detected using the volumetric technique.