Adsorption and Oxidation Investigations over Pt/Al2O3 Catalyst: A Microcalorimetric Study

The differential adsorption heats of oxygen and NO, as well as catalytic oxidation behavior during NO oxidation and NO2 dissociation reactions over supported Pt-catalysts, were investigated by microcalorimetric measurements. The average heat of adsorption (∆H) of oxygen ranged from 310 kJ/mol at 200 °C to 289 kJ/mol at 400 °C. Over this temperature range formation of platinum oxides and coverage dependence caused variations in the apparent heat of adsorption. NO heat of adsorption from 50 to 150 °C was near constant with an average value of 202 kJ/mol over the temperature range