STUDIES ON MIXED METAL OXIDES SOLID SOLUTIONS AS HETEROGENEOUS CATALYSTS

In this work, a series of perovskite-type mixed oxide LaMo(x)V(1-x)O(3+delta) powder catalysts (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0, with 0.5 < delta < 1.5), prepared by the sol-gel process and calcined at 750 degrees C, provide an attractive and effective alternative means of synthesizing materials with better control of morphology. Structures of resins obtained during the gel formation process by FT-IR spectroscopy and XRD analysis showed that all the LaMo(x)V(1-x)O(3+delta) samples are single phase perovskite-type solid solutions. The surface area (BET) between 2.5-5.0 m(2)/g (x = 0.1 and 1.0 respectively) increases with increasing Mo ratio in the samples. They show high purity, good chemical homogeneity, and lower calcinations temperatures as compared with the solid-state chemistry route. SEM coupled to EDS and thermogravimetric analysis/differential thermal analyses (TGA/DTA) have been carried out in order to evaluate the homogeneity of the catalyst. Finally, the experimental studies show that the calcination temperature and Mo content exhibited a significant influence on catalytic activity. Among the LaMo(x)V(1-x)O(3+delta) samples, LaMo(0.7)V(0.3)O(4.2) showed the best catalytic activity for the topic reaction and the best activity and stability for ethane reforming at 850 degrees C under 8 bar.