Promotion effect of urchin-like MnO x @PrO x hollow core-shell structure catalysts for the low-temperature selective catalytic reduction of NO with NH3

Shuyuan Cheng; Jing Shao; Bichun Huang; Jinkun Guan; Lusha Zhou

doi:10.1039/d0ra00668h

Promotion effect of urchin-like MnO _x @PrO _x hollow core-shell structure catalysts for the low-temperature selective catalytic reduction of NO with NH₃

RSC Adv. 2020 Apr 6;10(23):13855-13865. doi: 10.1039/d0ra00668h. eCollection 2020 Apr 1.

Authors

Shuyuan Cheng¹, Jing Shao¹, Bichun Huang^{1

2

3}, Jinkun Guan¹, Lusha Zhou¹

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre Guangzhou 510006 P. R. China cebhuang@scut.edu.cn.
² Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou Higher Education Mega Centre Guangzhou 510006 P. R. China.
³ The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre Guangzhou 510006 P. R. China.

Abstract

A MnO _x @PrO _x catalyst with a hollow urchin-like core-shell structure was prepared using a sacrificial templating method and was used for the low-temperature selective catalytic reduction of NO with NH₃. The structural properties of the catalyst were characterized by FE-SEM, TEM, XRD, BET, XPS, H₂-TPR and NH₃-TPD analyses, and the performance of the low-temperature NH₃-SCR was also tested. The results show that the catalyst with a molar ratio of Pr/Mn = 0.3 exhibited the highest NO conversion at nearly 99% at 120 °C and NO conversion greater than 90% over the temperature range of 100-240 °C. Also, the MnO _x @PrO _x catalyst presented desirable SO₂ and H₂O resistance in 100 ppm SO₂ and 10 vol% H₂O at the space velocity of 40 000 h^-1 and a testing time of 3 h test at 160 °C. The excellent low-temperature catalytic activity of the catalyst could ultimately be attributed to high concentrations of Mn⁴⁺ and adsorbed oxygen species on the catalyst surface, suitable Lewis acidic surface properties, and good reducing ability. Additionally, the enhanced SO₂ and H₂O resistance of the catalyst was primarily ascribed to its unique core-shell structure which prevented the MnO _x core from being sulfated.