The catalytic properties of supported cobalt phthalocyanines, containi
ng different substitutes, in oxidation of ethylmercaptan to disulphide
, have been studied in a flow system. The inclusion of electron-donor
substitutes in the phthalocyanine molecule leads to an increased catal
ytic activity, while electron-acceptor substitutes decrease it. In the
absence of NaOH the productivity of the most active catalyst samples
is unstable and drops quicker than that of the less active ones. In th
e presence of NaOH the activity of the phthalocyanines is stable and h
igh. This fact is explained and interpreted in terms of the mechanism
of the oxidation process.