West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical Inorganic Technology and Environment Engineering, Pułaskiego 10, 70-322 Szczecin, Poland
Prof. Dr. Zofia Lendzion-Bieluń
West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical Inorganic Technology and Environment Engineering, Pułaskiego 10, 70-322 Szczecin, Poland
An effect of promoters such as calcium, aluminium, and potassium oxides and also addition of chromium and manganese on the structure of cobalt catalysts was examined. Studies of the catalytic ammonia decomposition over the cobalt catalysts are presented. The studies of the ammonia decomposition were carried out for various ammonia-hydrogen mixtures in which ammonia concentration varied in the range from 10% to 100%. Co(0) catalyst, promoted by oxides of aluminium, calcium, and potassium, showed the highest activity in the ammonia decomposition reaction. Contrary to expectations, it was found that chromium and manganese addition into the catalysts decreased their activity.
The effect of an alkali treatment (potassium hydroxide) on the properties of a commercial activated carbon has been studied. The aim of the treatment was to improve the adsorption properties of the material toward carbon dioxide. In the result of the treatment, silica contained in the raw carbon was removed and the density of the material increased. The changes in the surface chemistry were observed as well. The treatment of the activated carbon with KOH resulted in a complete removal of carboxy and lactone groups and a decrease of the general content of the acidic groups (more significant than that of basic groups). Simultaneously, the surface concentration of hydroxyl groups increased. The alkali treatment of activated carbon resulted in an increase of carbon dioxide uptake of 14% (measured using a volumetric method at 0℃). The adsorption of carbon dioxide on activated carbon has a mixed (physicochemical) character and that two types of adsorption sites are present at the surface. The adsorption energy varies roughly from 25 to 60 kJ/mol.