Mixed Sb-V oxide catalysts are evaluated in the total selective removal of nitrogen-containing organic volatile compounds. Two different synthesis methods and two different supports (alumina and niobia) are studied. The combination of characterization before and after reaction and activity data is used to provide information about the structure-activity/selectivity relationship in vanadium antimonate catalysts. Best results are obtained with alumina-supported catalysts since niobia support tends to interact with antimony forming inert structures. When the catalysts are prepared with antimony tartrate soluble complex, the formation of VSbO4 is favoured; at the same time, the formation of segregated antimony oxides is inhibited. V5+ active sites on the Surface of catalysts reduce during the catalytic cycle to V3+ and are stabilized in the VSbO4 structure. (c) 2006 Elsevier B.V. All rights reserved.