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<p>Comparison investigations for the low-temperature SCR of NO<sub><i>x</i></sub> with NH<sub>3</sub> of a series of rare earth metal-doped RE<sub>0.1</sub>Mn<sub>0.9</sub>O<sub><i>x</i></sub> (RE = Sm, Eu, La, and Gd) catalysts were carried out. Performance test results showed that the optimized Sm<sub>0.1</sub>Mn<sub>0.9</sub>O<sub><i>x</i></sub> catalyst exhibited the best catalytic activity (above 91.8% NO conversion at 60‒160&#xa0;°C) and remarkable SO<sub>2</sub> tolerance (maintaining 98.0% NO conversion at 120&#xa0;°C). Detailed characterization revealed that Sm doping greatly increased the amount of Mn<sup>4+</sup> ratio (69.21%), active oxygen O<sub>α</sub> ratio (49.88%), and total acid sites (0.57&#xa0;mmol/g), while also enhancing the specific surface area (139.7 m<sup>2</sup>/g) and promoting the optimal redox property over the catalyst. Both Eley‒Rideal (E‒R) and Langmuir‒Hinshelwood (L‒H) mechanisms occurred on Sm<sub>0.1</sub>Mn<sub>0.9</sub>O<sub><i>x</i></sub> catalysts, but the E‒R mechanism was dominated in the reaction. The redox properties and surface acidity of the Sm<sub>0.1</sub>Mn<sub>0.9</sub>O<sub><i>x</i></sub> were effectively preserved after exposure to SO<sub>2</sub>, thereby maintaining high NO conversion. The doping of Sm effectively suppressed the MnSO<sub>4</sub> formation and accelerated (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> decomposition, thus improving the SO<sub>2</sub> tolerance of the catalyst. In this work, Sm was selected as the optimal rare earth element to enhance the catalytic ability of MnO<sub><i>x</i></sub> catalysts through comparative investigations. The promotional mechanisms of Sm doping on the ability and SO<sub>2</sub> resistance of MnO<sub><i>x</i></sub> catalysts were also revealed. These findings provide valuable insights into the design of efficient and SO<sub>2</sub>-tolerant catalysts for low-temperature deNO<sub><i>x</i></sub> applications.</p>

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Comparative investigation of the rare earth elements-doped MnOx catalysts by exploring the low-temperature SCR performance and SO2 resistance

  • 期刊论文

  • 发表日期：

    2025年7月22日

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  • Shengyang Zhang,
  • Shengen Zhang,
  • Boyu Wu,
  • Chencheng Hong,
  • Zeyu yang,
  • Bo Liu,
  • Bolin Zhang

摘要

Comparison investigations for the low-temperature SCR of NOx with NH3 of a series of rare earth metal-doped RE0.1Mn0.9Ox (RE = Sm, Eu, La, and Gd) catalysts were carried out. Performance test results showed that the optimized Sm0.1Mn0.9Ox catalyst exhibited the best catalytic activity (above 91.8% NO conversion at 60‒160 °C) and remarkable SO2 tolerance (maintaining 98.0% NO conversion at 120 °C). Detailed characterization revealed that Sm doping greatly increased the amount of Mn4+ ratio (69.21%), active oxygen Oα ratio (49.88%), and total acid sites (0.57 mmol/g), while also enhancing the specific surface area (139.7 m2/g) and promoting the optimal redox property over the catalyst. Both Eley‒Rideal (E‒R) and Langmuir‒Hinshelwood (L‒H) mechanisms occurred on Sm0.1Mn0.9Ox catalysts, but the E‒R mechanism was dominated in the reaction. The redox properties and surface acidity of the Sm0.1Mn0.9Ox were effectively preserved after exposure to SO2, thereby maintaining high NO conversion. The doping of Sm effectively suppressed the MnSO4 formation and accelerated (NH4)2SO4 decomposition, thus improving the SO2 tolerance of the catalyst. In this work, Sm was selected as the optimal rare earth element to enhance the catalytic ability of MnOx catalysts through comparative investigations. The promotional mechanisms of Sm doping on the ability and SO2 resistance of MnOx catalysts were also revealed. These findings provide valuable insights into the design of efficient and SO2-tolerant catalysts for low-temperature deNOx applications.