Mo-P-O/SiO_2催化剂上的异丁烷选择氧化反应

Selective Oxidation of Isobutane over Mo-P-O/SiO_2 Catalyst

采用溶胶 凝胶法制备了MoO3 /SiO2 和Mo P O/SiO2 催化剂 ,用X射线衍射、红外光谱、程序升温还原、程序升温脱附和活性评价等手段研究了催化剂的表面结构、晶格氧活泼性、化学吸附性能以及异丁烷选择氧化反应性能 .结果表明 ,活性组分在催化剂表面分散较好 ;异丁烷吸附在催化剂表面Lewis碱位的MoO端氧上形成分子吸附态 ;MoO3 /SiO2 和Mo P O/SiO2 两种催化剂对异丁烷选择氧化都有较好的选择性 ,将PO3 -4 引入到MoO3 /SiO2 催化剂中可提高含氧化合物的选择性 .

MoO3/SiO2 and Mo-P-O/SiO2 catalysts were prepared by the sol-gel method. The surface composition, activity of lattice oxygen, chemisorption, and activity of the catalysts were systematically studied by using X-ray diffraction, infrared spectroscopy, temperature-programmed reduction, temperature-programmed desorption, and microreactor techniques. The results showed that the active components can disperse on the surface of the catalysts as monolayer. Isobutane is chemisorbed on the surface terminal oxygen of the Lewis base sites Mo=O bonds by one or two H atoms of methyl to form molecular adsorption states. The activity and selectivity of MoO3/SiO2 and Mo-P-O/SiO2 catalysts are high for the selective oxidation of isobutane. The addition of PO43- improves the selectivity for C-4 oxygenate products.