Development of a multi-active center catalyst in mediating the catalytic destruction of chloroaromatic pollutants: A combined experimental and theoretical study
| Autor: | Jialuo Yuan, Xiaole Weng, Shuaiying Zhai, Jingkun Chen, Zhongbiao Wu, Pengfei Sun |
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| Rok vydání: | 2020 |
| Předmět: |
Reaction mechanism
Chemistry Process Chemistry and Technology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Catalysis Dissociation (chemistry) 0104 chemical sciences Active center chemistry.chemical_compound Adsorption Chlorobenzene Desorption Electrophile 0210 nano-technology General Environmental Science |
| Zdroj: | Applied Catalysis B: Environmental. 272:119015 |
| ISSN: | 0926-3373 |
| DOI: | 10.1016/j.apcatb.2020.119015 |
| Popis: | In this article, we unveiled the feasibility of designing a multi-active center catalyst system for the efficient destruction of chlorinated organics. Cu-HZSM-5 catalysts modified by Nb were developed, which was subsequently utilized for the catalytic elimination of chlorobenzene (CB). The underlying reaction mechanisms, particularly H2O activation and Cl adsorption/desorption behaviors, were explored using in situ DRIFTS, H2O-TPD and Density Functional Theory (DFT) calculations. Experimental results indicated that Bronsted acidic HZSM-5 and Nb-OH provided sufficient H protons to react with Cl, forming the HCl at low temperature and facilitating the Cl desorption. H2O molecule preferentially adsorbed on Cu-Nb interfaces, followed by dissociation on Cu sites, which generated enriched hydroxyls to form HCl. Dissociated Cl preferentially adsorbed on Nb sites that protected the active Cu species and maintained the activation of gaseous O2, thereby hindering electrophilic chlorination to form more toxic polychlorinated byproducts. |
| Databáze: | OpenAIRE |
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