Catalytic decomposition of PCDD/Fs on a V2O5-WO3/nano-TiO2 catalyst: effect of NaCl
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The effect of NaCl addition on the properties, activity, and deactivation of a V2O5-WO3/nano-TiO2 catalyst was investigated during catalytic decomposition of gas-phase polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The extent of deactivation relates directly to the NaCl loading of the catalyst. Poisoning by sodium neutralizes acid sites, interacts strongly with active VOx species, and reduces the redox capacity of catalysts. In addition, NaCl is also a chlorine source and may actually accelerate the synthesis of new PCDD/Fs. Washing a catalyst with dilute sulfuric acid largely restores catalytic activity, breaking the interaction of Na+ ions and dispersed vanadia and removing Na from the catalyst surface. Consequently, catalyst acidity and redox capacity almost recover. Furthermore, sulfate residues react with surface adsorbed water to generate Brønsted acid sites, ensuing a surge of strong acidity of the catalysts.
KeywordsMSW Na poisoning Deactivation Regeneration PCDD/Fs Catalytic decomposition
- Bertinchamps F, Grégoire C, Gaigneaux EM (2006) Systematic investigation of supported transition metal oxide based formulations for the catalytic oxidative elimination of (chloro)-aromatics: Part I: Identification of the optimal main active phases and supports. Appl Catal B-Environ 66:1–9. https://doi.org/10.1016/j.apcatb.2006.02.011 CrossRefGoogle Scholar
- Debecker DP, Bouchmella K, Delaigle R, Eloy P, Poleunis C, Bertrand P, Gaigneaux EM, Mutin PH (2010) One-step non-hydrolytic sol-gel preparation of efficient V2O5-TiO2 catalysts for VOC total oxidation. Appl Catal B-Environ 94:38–45. https://doi.org/10.1016/j.apcatb.2009.10.018 CrossRefGoogle Scholar
- Larrubia MA, Gutierrez-Alejandre A, Ramirez J, Busca G (2002) A FT-IR study of the adsorption of indole, carbazole, benzothiophene, dibenzothiophene and 4,6-dibenzothiophene over solid adsorbents and catalysts. Appl Catal a-Gen 224:167–178. https://doi.org/10.1016/s0926-860x(01)00769-4 CrossRefGoogle Scholar
- Yang Y, Zhang S, Wang S, Zhang K, Wang H, Huang J, Deng S, Wang B, Wang Y, Yu G (2015) Ball milling synthesized MnOx as highly active catalyst for gaseous POPs removal: significance of mechanochemically induced oxygen vacancies. Environ Sci Technol 49:4473–4480. https://doi.org/10.1021/es505232f CrossRefGoogle Scholar