In Situ FTIR Spectroscopy of 1-Butene and 1,3-Butadiene Selective Oxidation to Maleic Anhydride on V-P-O Catalysts

Article abstract of DOI:10.1021/j100291a046

The selective oxidation of 1-butene and 1,3-butadiene was studied by transmission infrared spectroscopy.Vanadium-phosphorous-oxygen catalysts prepared by the reaction of V2O5 with H3PO4 in alcohol solution were used.Infrared spectra were collected in situ during the flow of 75 cm³ of 1.5percent hydrocarbon-in-air mixtures over catalysts having P-to-V ratios of 0.9, 1.0, and 1.1.Reaction temperatures from 300 to 400 deg C were investigated with 1-butene feeds, whereas the highly reactive 1,3-butadiene was studied only at 300 deg C.An adsorbed butadiene species, maleic acid, maleic anhydride were observed during both olefin partial oxidation studies.Evidence was obtained for a second olefin species which had been previously observed for in situ n-butane selective oxidation studies.Concentrations of adsorbed species were found to vary with catalyst phosphorous loading, reaction temperature, and time of exposure to reaction conditions.