Ammonium Metavanadate - Metallurgy

Metallurgy

Ammonium metavanadate has been mixed with basic copper carbonate to make a new compound with better catalytic activity than the two separate compounds. In the study by Shaheen and Maksod, catalytic activity of different molar ratios of ammonium metavanadate in comparison with the two original compounds was examined at different calcinations temperatures. Crystalline structures and composition of compounds at certain temperatures were identified by X-ray diffraction and Differential thermal analysis (DTA) curves. Catalytic activity was measured “using hydrogen peroxide decomposition at 30, 40, and 50°C” for pure and mixed compounds. Pure ammonium metavanadate and basic copper carbonate exhibited very small catalytic activity at 300 and 500°C. Catalytic activity of the mixed molar ratios increased with the increase of ammonium metavanadate. No catalytic activity occurred at 750 and 1000° C for either pure or mixed. Shaheen and Maksod, believed that the increase in catalytic activity was due to “the increase in the concentration of active sites by creation of new ion pairs… as a result of mutual charge interaction” and no catalytic activity of 750 and 1000°C was due to “restrict ion of catalytically active constituents by the formation of copper vanadate compounds”. Monitoring of activation energy provided evidence that “the addition of increasing amounts of vanadium oxide resulted in a measurable decrease in” activation energy. The ESR spectra data from this study suggests that the catalytic activity is based on “the concept of bivalent catalytic centers.”