ABSTRACT
There are probably few if any catalysts that have received more research both on modified compositions of the new catalyst and on the bonding species in both the new and used catalyst. There are literally hundreds of papers and articles on the subject. Because the catalyst is heated during fabrication at temperatures approaching 700°C, there are, in addition to the species formed during preparation, solid-state reaction and with composition containing BiOx, MoOxPOx, SiO2, FeOx, and TiO2. There are many schemes used for the regeneration of the used catalyst. It is reported that the catalyst has unlimited life if it is regenerated by one of these methods. The basic method involves the replacement of the molybdenum that analysis of used catalyst indicates has sublimed from the catalyst particles. The Mo is replaced in the form of a spray, mist, or vapor containing MoO3 as the ammonium salt, the paramolybdate, or the trioxide.
