Page 177 - Principles of Catalyst Development

CATALYST CHARACTERIZATION 165
TABLE 7.8. Typical Results for SiOrSupported Noble Metals

Surface area
Catalyst H/M CO/M m Z g(me:tal- ' )
10% Pd 0.11 47
10% Rh 0.48 0.44 214
5% Rh 0.53 0.52 23~7
5% Ru 0.27 0.31 12'[
10% Ir 0.78 0.58 186

TABLE 7.9. Applications of Surface Area Measure·
ment by Chemisorption

Metal Adsorbate Referenct~
Fe CO 234
Ni, Co Hz, CO 231
Cu CO 235
Ag, Au °z 232
Pd CO 236
Pt, Ru, Rh, Ir Hz, CO 229
Ru °z 233

Chemisorption characterization of nonmetals has not been so fully
exploited. A few examples from the literature are given in Table 7.10. There
is no reason why the method should not be equally applicable to oxides
and sulfides. providing the necessary criteria of speciflcity. monolayer
coverage. and known stoichiometry are met.
The techniques for chemisorption measurement are the same as those
discussed for total adsorption and include volumetric, gravimetric and flow
methods. Each case is different. owing to the relative amounts of physical
adsorption that must be taken into account.(242)

TABLE 7.10. Applications of Chemisorption to NOlilmetals

Catalyst Adsorbate RefeH~nce
Mo0 3/SiOz °z 237
CrZ0 3/ Alz0 3 NO 238
NiO/Alz0 3 NO 239
NO 240, 241
Fez03/ AII0 3
MnOjAIz0 3 °z 242
KIO/Fe-AlzOz COz 234