Alkali metal-resistant mechanism for selective catalytic reduction of nitric oxide over V2O5/HWO catalysts

Running Kang, Junyao He, Feng Bin, Baojuan Dou, Qinglan Hao, Xiaolin Wei, Kwun Nam Hui, Kwan San Hui

Research output: Contribution to journalArticlepeer-review

Abstract

A series of V 2O 5/HWO catalysts are prepared by hydrothermal and impregnation methods using different precursors, among which the V 2O 5/HWO-C catalyst exhibited the optimal NH 3-SCR performance. Compared to oxalic acid (O) and water (W), commercial bacterial cellulose (C) as a precursor can firstly achieve a more controllable synthesis to form hexagonal WO 3 (HWO) of V 2O 5/HWO-C catalyst. Various characterization (XRD, N 2-BET, TEM, SEM, XPS, EDX mapping, and NH 3/NO-TPD-MS) indicate that a higher specific surface area, abundant active oxygen and surface acidity result from the V 2O 5/HWO-C catalyst. The reason is that HWO-C has an excellent and smooth rod-shaped morphology, which promotes high dispersion of V 2O 5 on its surface. In situ IR results show that the SCR follows the Langmuir-Hinshelwood (L-H) mechanism, where absorbed NO x intermediate species are formed on the V 2O 5 and react with the NH 4 + and NH 3abs groups of V 2O 5 and HWO. After loading 1.75 wt% K +, the obtained K-V 2O 5/HWO-C catalyst exhibits effective resistance to K poisoning and SO 2, and retains 78 % NO x conversion efficiency at 360 °C after 10 h, attributed to the effective capture of K + (1.04 wt%) in HWO-C channels via a new pathway, although approximately 0.71 wt% K + are located on HWO-C external surface with weak bonding to V 2O 5.

Original languageEnglish
Article number121445
JournalFuel
Volume304
Early online date23 Jul 2021
DOIs
Publication statusPublished - 15 Nov 2021

Keywords

  • Alkali metal-resistant
  • Commercial bacterial cellulose
  • Poisoning
  • SCR reaction
  • V O /HWO catalyst

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