催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (10): 843-848.

• 研究论文 • 上一篇    下一篇

新型MnOx催化剂用于低温NH3选择性催化还原NOx

唐晓龙1,郝吉明2,徐文国1,李俊华2   

  1. 1 北京理工大学化学物理研究所, 北京 1000812; 2 清华大学环境科学与工程系, 北京 100084
  • 收稿日期:2006-10-25 出版日期:2006-10-25 发布日期:2010-11-28

Novel MnOx Catalyst for Low-Temperature Selective Catalytic Reduction of NOx with NH3

TANG Xiaolong1, HAO Jiming2, XU Wenguo1, LI Junhua2   

  1. 1 The Institute for Chemical Physics, Beijing Institute of Technology, Beijing 100081, China; 2 Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China
  • Received:2006-10-25 Online:2006-10-25 Published:2010-11-28

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821

被引次数

127

摘要： 首次采用低温固相法制备了无载体MnOx催化剂并将其用于NOx的低温NH3选择性催化还原. 该催化剂为晶化度极低的混合锰氧化物,部分为粒径40～60 nm的棒状晶体颗粒,其余是更细小的无定形颗粒; 催化剂的BET比表面积为150.8 m2/g, 吸附能力较强, NOx吸附量可达138.27 μmol/g. 在模拟尾气试验条件下, MnOx催化剂的低温活性很高, 80 ℃时NOx转化率即可达到98.25%; 反应产物N2选择性高于96.6%; 当通入0.01%SO2和10%H2O后,由于竞争吸附导致NOx转化率有所下降,但仍可保持在70%左右,且不利影响在停止添加SO2和H2O后逐渐消失.

关键词: 锰氧化物, 低温选择性催化还原, 氮氧化物, 氨, 低温固相法

Abstract: A manganese oxide catalyst MnOx was prepared by the low-temperature solid phase reaction method and used for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. The X-ray diffraction results show that MnOx is a mixture of manganese oxides with poor crystallinity, which contains rodlike crystal particles (40～60 nm) and more fine amorphous particles. The BET specific surface area of the MnOx is 150.8 m2/g, more great than that of other unsupported catalysts ever reported, and thus its capability of adsorption is superior. In our experiments, the amount of adsorbed NOx reaches 138.27 μmol/g. The SCR results show that the MnOx is an efficient catalyst for the SCR of NOx at low temperature. A NOx conversion of 98.25% and product selectivity for N2 of 96.6% was obtained at 80 ℃. The addition of 0.01%SO2 and 10%H2O weakens the adsorption of NOx by competition on the catalyst surface, which decreases the NOx conversion to 70% after reaction for 2.5 h. The catalyst activity can be recovered after the removal of SO2 and H2O.

Key words: manganese oxide, low-temperature selective catalytic reduction, nitrogen oxide, ammonia, low-temperature solid phase reaction