程序升温表面反应技术研究氧化铈上H_2S的吸附和转化(英文)

Temperature-Programmed Surface Reaction Study of Adsorption and Reaction of H_2S on Ceria

采用程序升温表面反应技术研究了H2S在CeO2,TiO2和Al2O3三种载体上的吸附和反应行为.结果表明,CeO2具有最强的脱硫能力.系统研究了预处理气氛对H2S在CeO2上吸附和反应行为.发现CeO2的脱硫能力在惰性气氛、还原性气氛、氧化性气氛中依次增强.H2S首先吸附在经预处理的CeO2表面,进一步在Ar氛围下升温脱附时,一部分H2S在673K以下脱附,部分则与CeO2表面氧反应,在473K下产生硫和水,而在473～673K温度范围内,生成SO2.在673K以上,所生成的SO2进一步与晶格氧反应,转化成硫酸盐.后者在873K再次分解为SO2.因此,CeO2表面脱硫过程应控制在673K以下,可避免复杂的再生过程.

H2S adsorption and reaction on CeO2,TiO2,and γ-Al2O3 were studied by temperature programmed surface reaction（TPSR）.Ceria had the best desulfidation ability.The pretreatment atmosphere affected H2S adsorption and reaction on ceria,and desulfidation efficiency increased in the order of inert atmosphere,reducing atmosphere,oxidizing atmosphere.H2S was first adsorbed on pretreated ceria at room temperature.On increasing the temperature in an Ar（99.99%） atmosphere,part of the H2S desorbed below 673 K,and another part reacted with the surface oxygen on ceria to produce sulfur and water below 473 K,and SO2 between 473 and 673 K,which further reacted with lattice oxygen and was transformed into sulfate above 673 K.The sulfate decomposed into SO2 again at 873 K.To avoid the complex regeneration,it is advisable to carry out desulfidation below 673 K when using ceria as adsorbent.