催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (5): 403-408.

• 研究论文 • 上一篇    下一篇

原位漫反射红外光谱法研究SO2对Ag/Al2O3选择性催化丙烯还原NOx反应的影响

吴强,高洪伟,贺泓   

  1. 中国科学院生态环境研究中心环境化学与生态毒理学重点实验室, 北京 100085
  • 收稿日期:2006-05-25 出版日期:2006-05-25 发布日期:2006-05-25

Study of SO2 Effect on the Selective Catalytic Reduction of NOx with Propene over Ag/Al2O3 by in Situ DRIFTS

WU Qiang, GAO Hongwei, HE Hong*   

  1. State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, The Chinese Academy of Sciences, Beijing 100085, China
  • Received:2006-05-25 Online:2006-05-25 Published:2006-05-25

PDF

1129

被引次数

63

摘要： 以Ag/Al2O3为催化剂,采用原位漫反射傅里叶变换红外光谱法研究了SO2对C3H6选择性还原NOx反应的影响. 结果表明, SO2在催化剂表面转化为硫酸盐,并且随着硫酸盐累积量的增加,其主要红外特征吸收峰由低波数向高波数漂移. 高浓度表面硫酸盐的存在不仅抑制了催化剂表面硝酸盐的生成,而且抑制了硝酸盐与表面烯醇式物种(RCH=CH-O-)或乙酸盐物种进一步反应,生成活泼的反应中间体异氰酸酯(-NCO), 这是导致Ag/Al2O3催化剂上C3H6选择性还原NOx活性降低的主要原因.

关键词: 银, 氧化铝, 氮氧化物, 二氧化硫, 丙烯, 选择性催化还原, 原位漫反射傅里叶变换红外光谱, 硫酸盐

Abstract: In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to investigate the effect of SO2 on the selective catalytic reduction (SCR) of NOx by C3H6 over an Ag/Al2O3 catalyst. The DRIFTS spectra showed an obvious blue shift in the band of sulfate species when its coverage over Ag/Al2O3 was increased. The sulfate species not only inhibited the formation of NO-3, but also suppressed the reaction of enolic species or acetate species with NO-3 to form -[KG-20x]NCO species. These behaviors are responsible for the deactivation of Ag/Al2O3 during the SCR of NOx by C3H6 in the presence of SO2.

Key words: silver, alumina, nitrogen oxide, sulfur dioxide, propene, selective catalytic reduction, in situ diffuse reflectance infrared Fourier transform spectroscopy, sulfate species