Nitrogen-promoted active carbons as catalytic supports: 2. The influence of Mn promotion on the structure and catalytic properties in SCR

Catalytic properties of active carbons treated with N-compounds and promoted with manganese oxides were studied in selective catalytic reduction of NO with ammonia. The following elements of the preparation had a beneficial effect on activity and selectivity of the catalysts: pre-oxidation of active carbon prior to the introduction of N-species, the choice of N-compound, together with the post-treatment procedure, and the optimisation of the amount of active material. Apart from the introduction of N-surface groups, it was important to control the amount of acidic surface species which in turn determined the distribution of MeOx and reducibility of the samples, thus influencing the formation of undesired by-product (N2O).