Masakatsu Hatano

Ammoxidation of propane over Mo-V-Nb-Te mixed oxide catalysts

Mo-V-Nb-Te mixed metal oxides are highly active and selective for the ammoxidation of propane to acrylonitrile. Acrylonitrile yield reaches nearly 50% by the optimizing reactor temperature and NH3/propane feed ratio. The efficiency of the catalyst is higher than that of V-Sb and Bi-Mo mixed metal oxide catalysts. In addition to a higher acrylonitrile yield, the required reaction temperature is also lower. X-ray diffraction pattern and Raman spectrum of Mo-V-Nb-Te catalysts are unique. There are at least two crystal phases (Phase-M1 and Phase-M2), participating the elementary steps of the ammoxidation of propane, in Mo-V-Nb-Tc mixed metal oxide catalysts. Propane, seems to be activated on Phase-M1 to form dehydrogenated species, which transfer to Phase-M2. And the dehydrogenated species seem to react with activated NH species to form acryronitrilc via ρ-arryl species on Phase-M2.

Maleic anhydride by heterogeneous oxidation of n-butane

Abstract The catalytic performance of (VO) 2 P 2 O 7 , which is the industrial catalyst for the oxidation of n -butane to maleic anhydride, was studied in relation to the preparation methods of the catalyst and the reaction conditions when using the catalyst. It was shown that the difference in the preparation method resulted in a difference in the specific surface area of the catalyst, while the nature of the active sites was not affected by the preparation method. The catalyst running under the industrial operating conditions exhibited activity dependent on the oxygen concentration. A high oxygen concentration was preferable for a high catalytic performance of (VO) 2 P 2 O 7 . It was suggested that not only the activation of n -butane on the catalyst but also the reoxidation of the catalyst was important for the n -butane oxidation on (VO) 2 P 2 O 7 . The features of several industrial processes were also discussed in terms of practical industrial technology and the catalytic properties of (VO) 2 P 2 O 7 .