Adsorption of carbon monoxide on palladium during the catalyzed reaction CO + 1/2 O/sub 2/. -->. CO/sub 2/. [450/sup 0/C; flash desorption technique and a pressure jump method]

The amount of carbon monoxide adsorbed on palladium in the course of the catalyzed reaction CO + /sup 1///sub 2/O/sub 2/ ..-->.. CO/sub 2/ at 450 K was determined through analysis of the transient CO/sub 2/ formation which occurs following a carbon monoxide pressure jump. The results were compared with CO adsorption data obtained by flash desorption. The results of the two methods are in good accord. The amount of CO adsorbed when p/sub CO/ greater than p/sub O/sub 2// is almost equal to that determined in the CO/Pd equilibrium system (nonworking conditions). A sharp decrease in CO(a) is noted around p/sub CO/ approximately equal to p/sub O/sub 2// and CO(a) becomes very small when p/sub CO/ less than p/sub O/sub 2//. The inhibitory effect of CO(a) on the steady-state CO oxidation reaction is discussed on the basis of these CO adsorption isotherms determined under working conditions.