Determination of Specific Surface Area of Palladium in Hydrogenation Catalysts by Carbon Monoxide Chemisorption

Abstract

An apparatus for dynamic chemisorption measurement was built and a reliable experimental methodology based on determination of the specific surface area of Pd (S_Pd) and the average particle size of Pd (d_AV) in hydrogenation catalysts was developed using chemisorption of CO. Experimental conditions necessary for providing reproducibility of measured values were defined. The accuracy of the determination was verified by independent characterization techniques and by comparing chemisorption measurements of catalysts with the known characteristics. It was proved that the d_AV of Pd in the catalysts containing 2–5 wt.% Pd on commercial supports (Al₂O₃, active carbon, SiO₂, Al₂O₃-SiO₂), obtained by chemisorption measurements are in a good agreement with the results of other methods, the stoichiometry of CO adsorption on Pd being 1:2.