Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China.
J Hazard Mater. 2021 Mar 5;405:124223. doi: 10.1016/j.jhazmat.2020.124223. Epub 2020 Oct 9.
In order to enhance the catalytic activity of Mn-Ce oxide catalyst for the selective catalytic reduction of NO with NH (NH-SCR), W was introduced as a promoter. With the doping of W, the NO conversion over MnCeO catalyst above 150 °C was increased, and the NO production was significantly decreased. Even in the present of water vapour, MnCeWO still showed a good SCR activity. H-TPR and XPS results suggested that the doping of tungsten could inhibit the charge imbalance and reducibility, which would inhibit NO oxidation to NO over MnCeO. As a result, the NO conversion below 150 °C over MnCeWO was slightly lower than that over MnCeO. Since the NO production and the NH conversion during the NH oxidation of MnCeO were inhibited after the doping of W, the NO conversion above 150 °C over MnCeWO was higher than that over MnCeO. The transient reaction demonstrated that the doped W species on MnCeWO could inhibit the NO produced by the Langmuir-Hinshelwood mechanism. Kinetic study proved that ν over MnCeWO was obviously higher that over MnCeO, ν and ν over MnCeO were much higher than those of MnCeWO, which were consistent with the SCR activity.
为了提高 Mn-Ce 氧化物催化剂用于 NH（NH-SCR）选择性催化还原 NO 的催化活性，引入 W 作为促进剂。掺杂 W 后，MnCeO 催化剂在 150°C 以上的 NO 转化率增加，NO 生成量显著降低。即使存在水蒸气，MnCeWO 仍表现出良好的 SCR 活性。H-TPR 和 XPS 结果表明，掺杂钨可以抑制电荷不平衡和还原性，从而抑制 MnCeO 上的 NO 氧化为 NO。结果，MnCeWO 在 150°C 以下的 NO 转化率略低于 MnCeO。由于掺杂 W 后 MnCeO 上的 NH 氧化过程中的 NO 生成和 NH 转化率受到抑制，因此 MnCeWO 在 150°C 以上的 NO 转化率高于 MnCeO。瞬态反应表明，MnCeWO 上掺杂的 W 物种可以抑制由 Langmuir-Hinshelwood 机制产生的 NO。动力学研究证明，MnCeWO 上的 ν 明显高于 MnCeO，MnCeO 上的 ν 和 ν 远高于 MnCeWO，这与 SCR 活性一致。
