Calcination, and Shaping

In most cases catalyst precursors need a pretreatment before they can be used Besides drying normally a calcination step follows in which a sohd-state reaction at elevated temperature yields the active catalyst. In this reaction, anions (nitrates, oxalates, acetates, chlorides), as well as additives are decomposed or burnt and thereby removed from the catalysts. 

A parallel calcination apparatus that corresponds to the industrial used rotary kiln has been developed by Mayer et al. [109,]. Several tubes are arranged in a 

37 mixed-metal oxides based on Si02 andTiO  

---