Scholarlink

<p>Redox sites and acidic sites are the main active sites of bimetallic oxide catalysts used for selective catalytic oxidation of NH<sub>3</sub> (NH<sub>3</sub>-SCO). In this work, three MMoO<i>x</i> (M = Cr, Fe, and Mn) bimetallic oxides catalysts were prepared by simple grinding and calcination to investigate the effect of redox sites (M sites) on the NH<sub>3</sub>-SCO performance. The NH<sub>3</sub>-SCO test results showed that the activity of MMoO<i>x</i> is in the order of CrMoO<i>x</i> &gt; MnMoO<i>x</i> &gt; FeMoO<i>x</i>. The characterization results of H<sub>2</sub>-TPR, O<sub>2</sub>-TPD, NH<sub>3</sub>-TPD, and in situ DRIFTS proposed that the NH<sub>3</sub>-SCO reaction on MMoO<i>x</i> catalysts is proceed via i-SCR mechanism, and the formation of the intermediates of NH<sub>3</sub>-SCR reaction is the decisive reaction step. Owing to the excellent ability in promoting the formation of nitrate/nitrite species, CrMoO<sub><i>x</i></sub> and MnMoO<i>x</i> samples show much higher NH<sub>3</sub>-SCO activity than FeMoO<i>x</i> sample<i>.</i> CrMoO<sub><i>x</i></sub> can facilitate the formation of a large amount of –NH<sub>2</sub> species, which together with nitrate/nitrite species enhance the NH<sub>3</sub>-SCO reaction via i-SCR reaction route. Therefore, CrMoO<sub><i>x</i></sub> shows the highest NH<sub>3</sub>-SCO activity among the MMoO<i>x</i> catalysts. Through this work, the redox sites of bimetallic oxide catalysts are demonstrated as a vital role in inducing the formation of reaction-active intermediates, which highlight the importance of choosing the redox sites in designing NH<sub>3</sub>-SCO catalyst.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Regulating the redox sites of MMoOx (M = Mn, Fe, Cr) catalysts for highly efficient selective catalytic oxidation of NH3

  • 期刊论文

  • 发表日期：

    2025年6月26日

查看全文
  • Lan Hu,
  • Qiuyue Zhao,
  • Xinling Zhang,
  • Huipeng Li,
  • Cheng Bian,
  • Yiqing Zeng

摘要

Redox sites and acidic sites are the main active sites of bimetallic oxide catalysts used for selective catalytic oxidation of NH3 (NH3-SCO). In this work, three MMoOx (M = Cr, Fe, and Mn) bimetallic oxides catalysts were prepared by simple grinding and calcination to investigate the effect of redox sites (M sites) on the NH3-SCO performance. The NH3-SCO test results showed that the activity of MMoOx is in the order of CrMoOx > MnMoOx > FeMoOx. The characterization results of H2-TPR, O2-TPD, NH3-TPD, and in situ DRIFTS proposed that the NH3-SCO reaction on MMoOx catalysts is proceed via i-SCR mechanism, and the formation of the intermediates of NH3-SCR reaction is the decisive reaction step. Owing to the excellent ability in promoting the formation of nitrate/nitrite species, CrMoOx and MnMoOx samples show much higher NH3-SCO activity than FeMoOx sample. CrMoOx can facilitate the formation of a large amount of –NH2 species, which together with nitrate/nitrite species enhance the NH3-SCO reaction via i-SCR reaction route. Therefore, CrMoOx shows the highest NH3-SCO activity among the MMoOx catalysts. Through this work, the redox sites of bimetallic oxide catalysts are demonstrated as a vital role in inducing the formation of reaction-active intermediates, which highlight the importance of choosing the redox sites in designing NH3-SCO catalyst.