| Popis: |
We review the recent results on modified pentasil catalyst formation obtained using a variety of modern physical methods (XPS, TEM, EXAFS, etc). We also present some new data on the surface structure and catalytic properties of pentasils loaded with metals and oxides. The main problems discussed are: dispersion, electronic state and location of VIII Group metals in ZSM-5: the influence of preparation, metal content, zeolite acidity; properties of pentasils loaded with oxide phase: similarity and difference with metal silicates; promoting effects in bimetallic zeolite catalysts, well characterized metal alloy particles located within zeolite matrix. The characteristics studied are related to the catalytic properties of modified pentasils in aromatization and hydrogenolysis of lower alkanes. To follow the evolution of the catalyst surface the catalysts were investigated at different stages of the preparation and during catalytic reaction using in situ techniques (EXAFS, XPS) |
Plný text