Structure and properties of a supported M0O3-SBA-15 catalyst for selective oxidation of propene

摘要

Local structure and catalytic properties of molybdenum oxide supported on nanostructured SiO2 (SBA-15) were studied under reaction conditions by combined X-ray absorption spectroscopy (XAFS) and mass spectrometry.MoO3 supported on SBA-15 exhibits stability and catalytic properties different from those of binary bulk oxides.The interaction between support and molybdenum oxide stabilizes particular hexagonal MoO3 structure that is highly active and selective.The hex-MoO3-SBA-15 is stable under reducing (propene) and oxidizing reaction conditions in the temperature range from 20 to 500 °C.In contrast to bulk hex-MoO3,the onset of activity at about 250 °C is not accompanied by a transformation to alpha-MoO3.Moreover,in contrast to alpha-MoO3,hex-MoO3-SBA-15 is capable of directly oxidizing propene to acrylic acid without additional metal sites.