Catalytic properties of V–Ti–O catalysts in the oxidation and ammoxidation of o-xylene, acenaphthene and b-picoline
L.I.Saurambaeva and D.Kh.Sembaev
Catalytic properties of vanadium–titanium oxide catalysts in the oxidation and ammoxidation of o-xylene, acenaphthene and b-picoline have been studied. Methods of preparation of catalysts with varying amounts contents of V2O5 have been described. It has been shown that activity and selectivity in oxidation of organic compounds of different nature depends on the V2O5 content and the ratio of the oxides in the solid solution. Maximum selectivity in relation to phthalic and naphthalic anhydrides, naphthalimide and nitrile of nicotinic acid with the maximum conversion is observed with the catalysts having 4-6 wt.% of V2O5. Catalysts with other compositions showed lesser conversion of the initial substance. A catalyst, representing VO2–TiO2 solid solution, exhibits the least activity and selectivity among the tested samples for oxidation of o-xylene and ammoxidation of b-picoline. For oxidation and ammoxidation of acenaphthene, the least activity and selectivity are exhibited by a catalyst, containing alongside with the solid solution no more than 3% by weight of V2O5. Catalysts with an equal V2O5 amount, but differing one from the other by a composition of a solid solution, display different catalytic activity in o-xylene oxidation and b-picoline ammoxidation. Enrichment of solid solution with VO2 or a decrease in the amount of the latter in the content decrease activity and selectivity of a catalyst.