Characterization by temperature programmed reduction

Fresh and used EUROCAT Oxide-2 catalyst made up of V2O5, WO3 and TiO2 with SiO2, Al2O3 and CaO as main additives have been studied by means of tempera ture programmed reduction (TPR). As in the EUROCAT Oxide-1 project (V2O5/Ti O2 catalysts) for similar conditions similar profiles were obtained in the different laboratories, In contrast to the V2O5/TiO2 catalysts (EUROCAT Oxi de-1 project), where the vanadia content could be determined by TPR with re asonable reliability, the exact determination of the vanadia and tungsta lo ading for the ternary catalysts is not possible because of the occurrence o f several superimposed phenomena (reduction of vanadia, tungsta and titania and formation/reduction of CaWO4, reactions are not completed at maximal t emperature reached), which are not discernible by TPR. (C) 2000 Elsevier Sc ience B.V. All rights reserved.