摘要
采用超声波增强的浸渍法合成了组成优化的CeO_2-TiO_2(CeTi)催化剂。在200℃,模拟烟气条件下研究了SO_2对CeTi催化剂上单质汞(Hg^0)催化氧化的影响。结果表明:纯N_2条件下,SO_2抑制了CeTi催化剂上Hg^0的氧化;有O_2条件下SO_2既可以促进Hg^0的氧化,也可以抑制Hg^0的氧化,取决于烟气中SO_2的浓度。低浓度的SO_2在O_2的协助下可以促进Hg^0的氧化,而高浓度的SO_2抑制了Hg^0的氧化。实验条件下,SO_2本身不具有氧化Hg^0的能力,其对Hg^0氧化的促进作用源于其在CeTi催化剂表面反应生成的SO_3等活性物质。SO_2对Hg^0氧化的抑制作用归因于SO_2与Hg^0间的竞争吸附,SO_2抑制了Hg^0的吸附从而抑制了Hg^0的进一步氧化。
Abstract Effect of SO2 on elemental mercury （Hg0） oxidation over a highly active CeO2-TiO2 catalyst prepared by ultrasonic enhanced impregnation method was investigated at 200℃. SO2 was found to have different, even contrary, effects on Hg0 oxidation under different flue gas conditions. In pure N2 atmosphere, SO2 inhibited Hg0 oxidation. In N2 plus O2 atmosphere, low concentration of SO2 promoted Hg0 oxidation, while high level of SO2 deteriorated Hg0 oxidation. The promotional effect of SO2 on Hg0 oxidation was probably due to active species like SO3 generated from SO2 oxidation, and the inhibitive effect of SO2 on Hg0 oxidation was attributed to the competitive adsorption between SO2 and Hg0. Key words SO2; mercury; CeO2; catalyst; coal combustion
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2013年第9期1775-1778,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51206192
No.51176060)
中国博士后科学基金(No.2012M521549)
成都市企业自主创新项目(No.12GGYB838SF-001)
