STRUCTURAL SPECIFICITY OF MOLYBDENUM TRIOXIDE IN C4 HYDROCARBON OXIDATION

The structural specificity of MoO3catalysts in the oxidation of 1-butene, 1,3-butadiene, furan, and maleic anhydride has been investigated. MoO3samples exposing different ratios of (010) to (100) crystal faces have been prepared by temperature-programmed calcination and recrystallization methods. The catalysts have been characterized by using X-ray diffraction, laser Raman spectroscopy, a Raman microprobe, and scanning electron microscopy. The crystal dimensions have been determined by combining scanning electron microscopy with a three-dimensional (3-D) imaging technique. The steady-state oxidation experiments performed by using a fixed-bed, integral reactor over a temperature range from 410 to 600 °C showed the existence of a structural specificity for MOO3catalysts in the oxidation of C4hydrocarbons. It was found that the catalysts containing lower ratios of basal/edge planes were more selective toward partial oxidation products than those with high ratios, whereas the catalysts with high ratios were more active for complete oxidation. © 1990, American Chemical Society. All rights reserved.