TY - JOUR
T1 - A study on mn-fe catalysts supported on coal fly ash for low-temperature selective catalytic reduction of nox in flue gas
AU - Duan, Xiaoxu
AU - Dou, Jinxiao
AU - Zhao, Yongqi
AU - Rish, Salman Khoshk
AU - Yu, Jianglong
N1 - Funding Information:
Acknowledgments: The authors gratefully acknowledge the financial support of the Key R&D Funding Scheme of Liaoning Province (2017308008), Liaoning High-level Innovation Team Overseas Training Project (2018LNGXGJWPY-YB010), and ARC Linkage Project (LP160100540). The Talents Training Program of the University of Science and Technology Liaoning (2019RC12) is also acknowledged. The authors are grateful to Joy Omoriyekomwan and Joseph Appiah for assisting with manuscript writing.
Funding Information:
Funding: The work was carried out within a bilateral collaboration between the University of Science and Technology Liaoning and the University of Newcastle, which is financially supported by Key R&D Funding Scheme of Liaoning Province, China, grant no. 2017308008, Liaoning High-level Innovation Team Overseas Training Project, China, grant no. 2018LNGXGJWPY-YB010, and ARC Linkage Project, Australia, grant no. LP160100540.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/11/30
Y1 - 2020/11/30
N2 - A series of Mn0.15Fe0.05/fly-ash catalysts have been synthesized by the co-precipitation method using coal fly ash (FA) as the catalyst carrier. The catalyst showed high catalytic activity for low-temperature selective catalytic reduction (LTSCR) of NO with NH3 . The catalytic reaction experiments were carried out using a lab-scale fixed-bed reactor. De-NOx experimental results showed the use of optimum weight ratio of Mn/FA and Fe/FA, resulted in high NH3-SCR (selective catalytic reduction) activity with a broad operating temperature range (130–300◦C) under 50000 h−1 . Various characterization methods were used to understand the role of the physicochemical structure of the synthesized catalysts on their De-NOx capability. The scanning electron microscopy, physical adsorption-desorption, and X-ray photoelectron spectroscopy showed the interaction among the MnOx, FeOx, and the substrate increased the surface area, the amount of high valence metal state (Mn4+, Mn3+, and Fe3+), and the surface adsorbed oxygen. Hence, redox cycles (Fe3+ + Mn2+ ↔ Mn3+ + Fe2+; Fe2+ + Mn4+ ↔ Mn3+ + Fe3+) were co-promoted over the catalyst. The balance between the adsorption ability of the reactants and the redox ability can promote the excellent NOx conversion ability of the catalyst at low temperatures. Furthermore, NH3/NO temperature-programmed desorption, NH3/NO-thermo gravimetric-mass spectrometry (NH3/NO-TG-MS), and in-situ DRIFTs (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) results showed the Mn0.15Fe0.05 /FA has relatively high adsorption capacity and activation capability of reactants (NO, O2, and NH3) at low temperatures. These results also showed that the Langmuir–Hinshelwood (L–H) reaction mechanism is the main reaction mechanism through which NH3-SCR reactions took place. This work is important for synthesizing an efficient and environmentally-friendly catalyst and demonstrates a promising waste-utilization strategy.
AB - A series of Mn0.15Fe0.05/fly-ash catalysts have been synthesized by the co-precipitation method using coal fly ash (FA) as the catalyst carrier. The catalyst showed high catalytic activity for low-temperature selective catalytic reduction (LTSCR) of NO with NH3 . The catalytic reaction experiments were carried out using a lab-scale fixed-bed reactor. De-NOx experimental results showed the use of optimum weight ratio of Mn/FA and Fe/FA, resulted in high NH3-SCR (selective catalytic reduction) activity with a broad operating temperature range (130–300◦C) under 50000 h−1 . Various characterization methods were used to understand the role of the physicochemical structure of the synthesized catalysts on their De-NOx capability. The scanning electron microscopy, physical adsorption-desorption, and X-ray photoelectron spectroscopy showed the interaction among the MnOx, FeOx, and the substrate increased the surface area, the amount of high valence metal state (Mn4+, Mn3+, and Fe3+), and the surface adsorbed oxygen. Hence, redox cycles (Fe3+ + Mn2+ ↔ Mn3+ + Fe2+; Fe2+ + Mn4+ ↔ Mn3+ + Fe3+) were co-promoted over the catalyst. The balance between the adsorption ability of the reactants and the redox ability can promote the excellent NOx conversion ability of the catalyst at low temperatures. Furthermore, NH3/NO temperature-programmed desorption, NH3/NO-thermo gravimetric-mass spectrometry (NH3/NO-TG-MS), and in-situ DRIFTs (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) results showed the Mn0.15Fe0.05 /FA has relatively high adsorption capacity and activation capability of reactants (NO, O2, and NH3) at low temperatures. These results also showed that the Langmuir–Hinshelwood (L–H) reaction mechanism is the main reaction mechanism through which NH3-SCR reactions took place. This work is important for synthesizing an efficient and environmentally-friendly catalyst and demonstrates a promising waste-utilization strategy.
KW - Co-impregnation method
KW - Coal fly ash
KW - De-NO efficiency
KW - Low-temperature SCR
KW - MnFe/FA catalysts
UR - https://www.scopus.com/pages/publications/85097229757
U2 - 10.3390/catal10121399
DO - 10.3390/catal10121399
M3 - Article
AN - SCOPUS:85097229757
SN - 2073-4344
VL - 10
JO - Catalysts
JF - Catalysts
IS - 12
M1 - 1399
ER -