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Montmorillonites modified with carbon deposits were reported to be promising catalysts of NO reduction with ammonia (SCR). The influence of different preparation methods on structural, textural and sorption properties were discussed. Three preparation methods were considered, differing in the pretreatment of the clay preceding the introduction of carbon precursor (polymer soluble in water). The structure was studied by XRD, texture by sorption of argon, benzene and carbon tetrachloride and surface composition by XPS. The obtained nanocomposites had different textural properties, depending on pretreatment. XPS, TPD and textural data suggest different mechanisms of formation of nanocomposites on untreated and acidic pretreated clays. The introduction of carbon deposits influenced hydrophilic properties. The number of ammonia sites changed after each preparative step: acidic pretreatment, pillaring and the formation of carbon deposits. [Copyright &y& Elsevier]

Abstract: 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 MeO x and reducibility of the samples, thus influencing the formation of undesired by-product (N2O). [Copyright &y& Elsevier]