H_2O和SO_2对V_2O_5-WO_3/TiO_2催化剂催化氧化NO的影响

Effects of H_2O and SO_2 on catalytic oxidation of NO by V_2O_5-WO_3/TiO_2 catalyst

研究了在120℃的反应温度下,H2O和SO2对V2O5-WO3/TiO2催化剂选择性催化氧化(SCO)NO的影响。结果表明,在H2O和SO2存在的情况下催化剂失活很快,停止通入H2O和SO2后活性不能恢复,但在加热到250℃后催化活性基本恢复。FT-IR分析表明,催化剂表面形成了金属硝酸盐和Ti的硫酸盐,对催化活性有一定影响,但不影响催化剂在250℃下催化活性的恢复。SO2、H2O和NO的竞争吸附与SO2和NO2的铅室反应是影响催化剂活性的主要原因。

A catalyst of vanadium pentoxide-tungsten trioxide supported on TiO2 was prepared and applied for selective catalytic oxidation（SCO） of NO in the presence of excessive oxygen at 120 ℃.The effects of H2O and SO2 on the catalyst were studied.The results showed that H2O and SO2 had negative impact on the activity,and the deactivated catalyst can＇t recovery when H2O and SO2 were stopped.The FT-IR spectra showed that the metal nitrates and Ti sulfates formed during SCO reaction.The catalyst was deactivated gradually,but its activity could almost be recovered to the initial level after heat treatment at 250 ℃.The major causes that affect the catalyst activity are the competitive adsorption of SO2,H2O,NO and the reaction of SO2,NO2.