A new chemisorption methodology involving H2 and CO for estimation of surface Pd atoms in supported catalysts

A new room temperature static hydrogen chemisorption methodology has been developed for the estimation of surface Pd atoms in supported catalysts. The methodology involves adsorption of H2 on clean and CO covered Pd surface. Following the methodology, the problem related to hydrogen absorption in the bulk of palladium (bulk hydrogen) is nullified truly and the real amount of the Pd atoms exposed on the surface is determined. It is established that chemisorbed CO over-layer does not block/restrict passage of hydrogen into the bulk of Pd. It is also revealed that room temperature evacuation does not remove bulk hydrogen completely.