Cd-clinoptilolites were prepared using the conventional aqueous phase ion exchange procedure and by reacting a mixture of cadmium dust and NH4-clinoptilolite powder around 310 °C, i.e., near to the melting point of the metal. The solid phase reaction was indicated by H2 evolution and the decrease of XRD line intensities of cadmium metal. The NH3, leaving the cationic sites was retarded to some extent by cadmium species. Higher degree of ion exchange was achieved using the solid phase reaction than by the conventional aqueous phase procedure. The catalytic activities of the preparations were compared in hydration of acetylene. The activities were tested in IR cell by reacting gas phase acetylene at 100 °C with water adsorbed on the catalyst wafer resulting in formation of adsorbed acetaldehyde. The catalyst prepared by the aqueous phase Cd-exchange was more active, however, after treatment at 300 °C, i.e., at temperature close to that of the solid phase reaction, its activity was essentially lower than that of the solid state preparation.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry