SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (7): 1925-1934.DOI: 10.1016/j.cjche.2020.01.004

• Energy, Resources and Environmental Technology • 上一篇    下一篇

Overwhelming low ammonia escape and low temperature denitration efficiency via MnOx-decorated two-dimensional MgAl layered double oxides

Junqi Tian1, Yanqin Li1, Xia Zhou1, Yongbin Yao1, Denghao Wang1, Jianming Dan1, Bin Dai1, Qiang Wang2, Feng Yu1,3   

  1. 1 Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China;
    2 Environmental Functional Nanomaterials Laboratory, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China;
    3 Bingtuan Industrial Technology Research Institute, Shihezi University, Shihezi 832003, China
  • 收稿日期:2019-10-30 修回日期:2019-12-25 出版日期:2020-07-28 发布日期:2020-08-31
  • 通讯作者: Qiang Wang, Feng Yu
  • 基金资助:
    The work was supported by Science and Technology Innovation Talents Program of Bingtuan (No. 2019CB025), and Major Scientific and Technological Project of Bingtuan (No. 2018AA002).

Overwhelming low ammonia escape and low temperature denitration efficiency via MnOx-decorated two-dimensional MgAl layered double oxides

Junqi Tian1, Yanqin Li1, Xia Zhou1, Yongbin Yao1, Denghao Wang1, Jianming Dan1, Bin Dai1, Qiang Wang2, Feng Yu1,3   

  1. 1 Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China;
    2 Environmental Functional Nanomaterials Laboratory, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China;
    3 Bingtuan Industrial Technology Research Institute, Shihezi University, Shihezi 832003, China
  • Received:2019-10-30 Revised:2019-12-25 Online:2020-07-28 Published:2020-08-31
  • Contact: Qiang Wang, Feng Yu
  • Supported by:
    The work was supported by Science and Technology Innovation Talents Program of Bingtuan (No. 2019CB025), and Major Scientific and Technological Project of Bingtuan (No. 2018AA002).

摘要: Low temperature catalysts are attracting increasing attention in the selective catalytic reduction (SCR) of NO with NH3. MnOx-decorated MgAl layered double oxide (Mn/MgAl-LDO) was synthesized via a facile fast pour assisted co-precipitation (FP-CP) process. Compared to the Mn/MgAl-LDO obtained via slow drop assisted coprecipitation (SD-CP) method, the Mn/MgAl-LDO (FP-CP) has excellent activity. The Mn/MgAl-LDO (FP-CP) catalyst was shown to possess a high NO conversion rate of 76%-100% from 25 to 150 ℃, which is much better than the control Mn/MgAl-LDO (SD-CP) (29.4%-75.8%). In addition, the Mn/MgAl-LDO (FP-CP) offered an enhanced NO conversion rate of 97% and a N2 selectivity of 97.3% at 100 ℃; the NO conversion rate was 100% and the N2 selectivity was 90% at 150 ℃ with a GHSV of 60,000 h-1. The Mn/MgAl-LDO (FP-CP) catalyst exhibited a smaller fragment nano-sheet structure (sheet thickness of 7.23 nm). An apparent lattice disorder was observed in the HRTEM image confirming the presence of many defects. The H2-TPR curves show that the Mn/MgAl-LDO (FPCP) catalyst has abundant reducing substances. Furthermore, the enhanced surface acidity makes the NH3 concentration of the Mn/MgAl-LDO (FP-CP) catalyst lower than 100 ml·m-3 after the reaction from 25 to 400 ℃. This can effectively reduce the ammonia escape rate in the SCR reaction. Thus, the Mn/MgAl-LDO (FP-CP) catalyst has potential applications in stationary industrial installations for environmentally friendly ultra-low temperature SCR.

关键词: Layered double oxide, Fast pour assisted co-precipitation, Selective catalytic reduction, Low temperature catalytic, Ammonia escape

Abstract: Low temperature catalysts are attracting increasing attention in the selective catalytic reduction (SCR) of NO with NH3. MnOx-decorated MgAl layered double oxide (Mn/MgAl-LDO) was synthesized via a facile fast pour assisted co-precipitation (FP-CP) process. Compared to the Mn/MgAl-LDO obtained via slow drop assisted coprecipitation (SD-CP) method, the Mn/MgAl-LDO (FP-CP) has excellent activity. The Mn/MgAl-LDO (FP-CP) catalyst was shown to possess a high NO conversion rate of 76%-100% from 25 to 150 ℃, which is much better than the control Mn/MgAl-LDO (SD-CP) (29.4%-75.8%). In addition, the Mn/MgAl-LDO (FP-CP) offered an enhanced NO conversion rate of 97% and a N2 selectivity of 97.3% at 100 ℃; the NO conversion rate was 100% and the N2 selectivity was 90% at 150 ℃ with a GHSV of 60,000 h-1. The Mn/MgAl-LDO (FP-CP) catalyst exhibited a smaller fragment nano-sheet structure (sheet thickness of 7.23 nm). An apparent lattice disorder was observed in the HRTEM image confirming the presence of many defects. The H2-TPR curves show that the Mn/MgAl-LDO (FPCP) catalyst has abundant reducing substances. Furthermore, the enhanced surface acidity makes the NH3 concentration of the Mn/MgAl-LDO (FP-CP) catalyst lower than 100 ml·m-3 after the reaction from 25 to 400 ℃. This can effectively reduce the ammonia escape rate in the SCR reaction. Thus, the Mn/MgAl-LDO (FP-CP) catalyst has potential applications in stationary industrial installations for environmentally friendly ultra-low temperature SCR.

Key words: Layered double oxide, Fast pour assisted co-precipitation, Selective catalytic reduction, Low temperature catalytic, Ammonia escape