化工学报2016，Vol.67Issue(12)：5031-5039,9.DOI:10.11949/j.issn.0438-1157.20160953
MnOx/WO3/TiO2低温选择性催化还原NOx机理的原位红外研究
In situ FT-IR studies on low temperature NH3-SCR mechanism of NOx over MnOx/WO3/TiO2catalyst
摘要
Abstract
15% MnOx/5% WO3/ TiO2catalyst for low-temperature selective catalytic reduction of NOx was synthesized by an impregnation method. NH3-SCR mechanism was explored systematically and possible pathway was proposed throughin situ FT-IR study on microscopic transient and steady states under various conditions of single or mixed gas feed with multiple pre-treatment. The results revealed that NH3-SCR reaction over the 15%MnOx/5%WO3/TiO2catalyst proceeded mainly by the Eley-Rideal mechanism with the Langmuir- Hinshclwood pathway only at certain temperature. NH3 adsorbed on the Lewis acid sites of the catalyst surface was the main source of reductant; however, more NH+4adsorbed on the Brønsted acid sites of the catalyst surface involved in the NOx reduction with increase of reaction temperature. The adsorption and activation of NH3was key step for the whole SCR reaction. NO2 easily reacted with adsorbed NH3 with stronger affinity to catalyst surface than NO. The bidentate nitrate, which formed considerably at oxidation active centers of the catalyst by NO adsorption, didn’t participate in NH3-SCR reaction but obstructed adsorption and activation of NH3. O2could promote NH3-SCR by blocking formation of bidentate nitrate. The adsorption of NO and NH3 on the catalyst surface was competitive at room temperature, which NO adsorption was higher than NH3 at O2 absence. The absorbed NH3 could be massively activated and reacted with NOxupon temperature reached to 100℃.关键词
MnOx/WO3/TiO2催化剂/原位红外/NH3-SCR脱硝机理/制备/吸附/活化Key words
MnOx/WO3/TiO2 catalyst/in situ FT-IR/NH3-SCR mechanism/preparation/adsorption/activation分类
通用工业技术引用本文复制引用
廖永进,张亚平,余岳溪,李娟,郭婉秋,汪小蕾..MnOx/WO3/TiO2低温选择性催化还原NOx机理的原位红外研究[J].化工学报,2016,67(12):5031-5039,9.基金项目
国家自然科学基金项目（51306034）；江苏省重点研发计划项目（BE2015677）。@@@@supported by the National Natural Science Foundation of China(51306034) and the Key R & D Projects of Jiangsu Province (BE2015677) （51306034）
