ESR study of reduced vanadium-titanium oxide catalysts

Reduction of vanadium-titanium oxide catalysts with hydrogen in the tempera ture range of 150-450 degrees C results in the increase of the content of V 4+ ions in substitution positions of TiO2 with the anatase structure. The t emperature increase up to 250 degrees C results in the growth of the spectr al intensity of V4+ associates in substitution positions of anatase. At hig her treatment temperatures their intensity decreases due to the formation o f VO2 fragments in anatase. At 400 degrees C and higher temperatures a soli d solution of V4+ ions in rutile is formed.