A calorimetric, IR, XANES and EXAFS study of the adsorption of NH3 on Ti-silicalite as a function of the sample pre-treatment

The interaction of NH, with Ti-silicalite-1 (TS-1) was studied by means of adsorption microcalorimetry IR, XANES and EXAFS techniques. A specific interaction with T1(IV) sites was revealed and quantitatively and energetically described, in comparison with silicalite taken as a reference material. The adsorption was found to be largely reversible but a minor amount of ammonia was irreversibly held at the surface of TS-1. The energetic spectrum obtained by the heat of adsorption versus coverage plot is quite wide in both TS-1 (40