Über die katalytische Ammoniakoxydation. III

The Historical Development of Catalytic Oxidation Processes

“…Of much greater significance in this area has been the information which has accumulated on the effects of operating variables. Andrussov [123] in early laboratory work showed the relationship between the selectivity of the reaction, i.e. : the percent of ammonia fed which is converted to nitric oxide, the contact time and catalyst temperature ( Figure 3).…”

“…Prior to 1960 three reaction theories, named after the principal intermediates proposed, were current, vi::. : the imide (NH) theory of Raschig [122], the nitroxyl (NHO) theory of Andrussov and Bodenstein [123] and the hydroxylamine theory (NH 2 0H) of Bodenstein [124]. Since 1960, understanding of the .mechanism of ammonia oxidation has been advanced by four groups of workers each using molecular beam conditions at low pressures; Fogel ('{ al.…”

“…Figure 3. Selectivity for ammonia oxidation as a function of temperature and contact time [123]0 t, contact time in seconds Whilst higher temperatures have been shown to improve the selectivity of reaction, this advantage is to some extent offset by a rapid increase in the loss of platinum from the catalyst in service and by a decrease in mechanical strength of the gauze with resulting reduction in catalyst life. The balancing of these factors has had a significant effect on the development of the catalyst composition and on its manner of use.…”