4.6 Article

Tuning the catalytic properties of La-Mn perovskite catalyst via variation of A- and B-sites: effect of Ce and Cu substitution on selective catalytic reduction of NO with NH3

Journal

RSC ADVANCES
Volume 12, Issue 35, Pages 22881-22892

Publisher

ROYAL SOC CHEMISTRY
DOI: 10.1039/d2ra04085a

Keywords

-

Funding

  1. National natural science foundation of China [52006016, 52104391]
  2. State scholarship fund - China scholarship [201808430112]
  3. Natural science foundation of Hunan province [2020JJ4098, 2021JJ40573]
  4. Key projects of scientific research project of Hunan Provincial Department of Education [21A0216]
  5. Changsha Municipal Natural Science Foundation [kq2014104]
  6. Young teachers growth plan project of CSUST [2019QJCZ044]
  7. Key laboratory of renewable energy electric technology of Hunan province [2016ZNDL005, 2018ZNDL004, 2020ZNDL001]
  8. 2022 Graduate research and innovation project at Changsha University of Science and Technology [CXCLY2022092]

Ask authors/readers for more resources

Perovskites with flexible structures and excellent redox properties are promising catalysts for denitration reactions. In this study, the effect of Ce and Cu substitution on the physicochemical properties of perovskite catalysts in an NH3-SCR system was investigated. The results showed that Ce substitution improved the denitration activity of LaMnO3 catalysts, while Cu substitution further enhanced the denitration activity. The higher denitration activity of La0.9Ce0.1MnO3 was primarily attributed to its larger surface area, which facilitated the adsorption of NH3 and NO. On the other hand, the improved denitration activity of La0.9Ce0.1Mn0.8Cu0.2O3 was due to the development of Cu active sites and Ce3+ content, which promoted redox reactions on the catalyst surface. The findings highlight the importance of appropriate cerium and copper substitution in enhancing the denitration activity of La-Mn perovskite catalysts.
Perovskites with flexible structures and excellent redox properties have attracted considerable attention in industry, and their denitration activities can be further improved with metal substitution. In order to investigate the effect of Ce and Cu substitution on the physicochemical properties of perovskite in NH3-SCR system, a series of La1-xCexMn1-yCuyO3 (x = 0, 0.1, y = 0, 0.05, 0.1, 0.2, 0.4) catalysts were prepared by citrate sol-gel method and employed for NO removal in the simulated flue gas, and the physical and chemical properties of the catalysts were studied using XRD, SEM, BET, XPS, DRIFT characterizations. The Ce substitution on A-site cation of LaMnO3 can improve the denitration activity of the perovskite catalyst, and La0.9Ce0.1MnO3 displays NO conversion of 86.7% at 350 degrees C. The characterization results indicate that the high denitration activity of La0.9Ce0.1MnO3 is mainly attributed to the larger surface area, which contributes to the adsorption of NH3 and NO. Besides, the appropriate Cu substitution on B-site cation of La0.9Ce0.1MnO3 can further improve the denitration activity of perovskite catalyst, and La0.9Ce0.1Mn0.8Cu0.2O3 displays the NO conversion of 91.8% at 350 degrees C. Although the specific surface area of La0.9Ce0.1Mn0.8Cu0.2O3 is lower than La0.9Ce0.1MnO3, the Cu active sites and the Ce3+ contents are more developed, making many reaction units formed on the catalyst surface and redox properties of catalyst improved. In addition, strong metal interaction (Ce4+ + Mn2+ + Cu2+ <-> Ce3+ + Mn3+/Mn4+ + Cu+) and high concentrations of chemical adsorbed oxygen and lattice oxygen both strengthen the redox reaction on catalyst surface, thus contributing to the better denitration activity of La0.9Ce0.1Mn0.8Cu0.2O3. Therefore, appropriate cerium and copper substitution will markedly improve the denitration activity of La-Mn perovskite catalyst. We also reasonably conclude a multiple reaction mechanism during NH3-SCR denitration process basing on DRIFT results, which includes the Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available