Metal Surface Area and Metal Dispersion in Catalysts

摘要

Methods for the determination of free-metal surface areas are surveyed. Iron, copper, silver, gold, nickel, cobalt, palladium and platinum (but not alloy catalysts) are considered. Recommendations are made with respect to the choice of the adsorbate, the measuring technique and data interpretation. Techniques for the adsorption of carbon monoxide on a singly promoted ammonia synthesis catalyst, the adsorptive decomposition of nitrous oxide, oxygen chemisorption, hydrogen chemisorption and hydrogen-oxygen titration are described. The effects due to the condition of the metal surface after pre-treatment, the presence of impurities, and the non-inert nature of the support are considered. Formulas used in X-ray and electron microscope techniques for particle detection, when determining dispersion and mean particle size, are considered.