DETERMINATION OF THE SURFACE-AREA OF RUTHENIUM CATALYSTS BY REDOX TITRATION IN LIQUID SUSPENSION WITH POTENTIOMETRIC INDICATION

A method for the surface area determination of metallic ruthenium was tested, It was based on oxidation of the prereduced catalyst in a liqu id suspension with chromate and with potentiometric indication, It was shown that, as compared with a standard BET measurement of metal blac ks, such a technique gave excellent results, especially for ruthenium black and SiO2- and Al2O3-supported catalysts, These supports did not follow redox surface changes, On the other hand the method was less ac curate for active carbon-supported ruthenium, since a considerable vol ume of the titrating agent was consumed by support surface composition changes.