Oxidation of methanol on sodium modified chromium–molybdenum catalysts

Abstract The effect of sodium on catalytic properties of the Cr–Mo-based catalysts for methanol oxidation was investigated. The samples were prepared by (i) - precipitation from 5 wt.% aqueous solutions of chromium nitrate and sodium molybdate (ii) - impregnation of preliminary synthesised catalyst with aqueous solutions of NaNO 3 , vaporising, drying and calcination at 500°C in the course of 5 h. Formation of a new compound with composition Na 2 O.Cr 2 O 3 .3MoO 3 was established. The results obtained allowed our conclusion that the sodium effects on the properties of the catalysts depended strongly both on the way of its introduction into the system and the composition and properties of the compounds it formed.