Pillared smectite modified with carbon and manganese as catalyst for SCR of NOx with NH3. Part II. Temperature-programmed studies

Temperature-programmed desorption (TPD) and surface reaction (TPSR), and ad ditionally FTIR spectroscopy of adsorbed NO molecules were used to characte rise surface sites on pillared smectites modified with carbon and manganese . Much higher adsorption of NH3 than NO was found, but acidic pre-treatment increased NO sorption to comparable values as well as catalytic performanc e in SCR of NOx. In this case formation of strongly bound NO3- species was recognised, which reacted with NH3 at a temperature 200 degreesC higher tha n weaker adsorbed NO.