催化剂载体γ-Al_2O_3上NO对SO_2的氧化吸附  

Effect of NO on SO_2 Oxidation Adsorption over Catalyst Support γ-Al_2O_3

作　　者：陈英[1] 李雪辉[1] 徐建昌[1] 黄苑[1] 王乐夫[1] 

机构地区：[1]华南理工大学化工与能源学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2004年第11期1-5,共5页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目 (2 0 0 76 0 17) ;广东省自然科学基金资助项目 (0 30 95 1)

摘　　要：通过研究催化剂载体γ Al2 O3在 4 2 3K吸附温度和不同气氛 (有氧和无氧 )下NO和SO2 的吸附曲线、吸附量 ,以及漫反射红外光谱 (DRIFTS)分析 ,探讨了低温下在γ Al2 O3上NO对SO2 的氧化吸附的影响 .研究表明 ,低温下在γ Al2 O3上NO对SO2 氧化吸附有促进作用 ,γ Al2 O3晶格氧直接参与了NO促进SO2 氧化的反应 .NO促进SO2 氧化吸附的机理是 :γ Al2 O3吸附NO形成的表面螯合亚硝基与邻位弱吸附的Al—O—SO2 发生表面反应 ,使弱吸附的Al—O—SO2 氧化生成稳定的SO2 - 4,并产生氧空位 ,放出NO ,气相中的氧补充氧空位生成晶格氧 ,使表面反应得以继续进行 .The adsorption profiles and storage capabilities of NO and SO 2 over the catalyst support γ-Al 2O 3 were explored at an adsorption temperature of 423 K and with different atmospheres (with oxygen or without oxygen), and the states of adsorbed SO 2 and NO were studied by DFIRFS (Diffuse Reflection Infrared Spectroscopy). Thus, the effect of NO on SO 2 oxidation adsorption at a low temperature was observed. The results show that, at a low temperature, NO can promote the oxidation adsorption of SO 2 over γ-Al 2O 3, and that the lattice oxygen of γ-Al 2O 3 is directly taken part in the promotion reaction. The promotion mechanism is that there arises a surface reaction of chelating nitro complexes resulting from γ-Al 2O 3 adsorbing NO with the vicinal weakly adsorbed Al—O—SO 2, and that the surface reaction makes the weakly adsorbed Al—O—SO 2 form stable sulfate ions (SO 4 2- ) and oxygen vacancies, release NO, and supply the oxygen vacancies with oxygen in gas phase to form lattice oxygen , thus setting the surface reaction going on and on.

关 键 词：Γ-氧化铝 二氧化硫 一氧化氮 氧化吸附 机理 

分 类 号：X842[环境科学与工程—环境工程]