Description:
<jats:title>Abstract</jats:title>
<jats:p>In order to measure the small surface area of metal foils down to a few ten square centimeters by making use of gas adsorption, an apparatus was developed, which made it possible to estimate the amount of adsorbed xenon at 77.5°K from the desorption of the gas on the surface by moving the foil from the adsorbing bulb into the hot furnace; the change in the surface area of palladium foil catalysts which had been annealed at various temperatures was followed by the use of this method. The roughness factor, the ratio of the real surface area to the geometrical one, of the palladium foil decreased from 1.7 to 1.1 with the progress of annealing at 150–300°C, but it increased to 1.9 after heating at 400°C and then decreased again under treatment at high temperatures to 1.0 for 800°C. The chemisorption of carbon monoxide on the same foil catalyst, which is often used for the surface-area determination, was also studied, and the difference between the adsorbed states of the respective molecule on the palladium surface was briefly discussed in order to compare these methods.</jats:p>