Modeling the Adsorption of NO and NH3 on Fe-SSZ-13 from First-Principles: A DFT Study
| Autor: | Kyle Groden, Jean-Sabin McEwen, Renqin Zhang, Emily S. Anderst |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Reducing agent General Chemical Engineering Inorganic chemistry Selective catalytic reduction General Chemistry 010402 general chemistry 01 natural sciences Industrial and Manufacturing Engineering 0104 chemical sciences Catalysis Ammonia chemistry.chemical_compound SSZ-13 Adsorption chemistry Density functional theory NOx |
| Zdroj: | Industrial & Engineering Chemistry Research. 57:13396-13405 |
| ISSN: | 1520-5045 0888-5885 |
| Popis: | As emission standards continue to tighten, there is a critical need for more selective and efficient methods to remove NOx from the exhaust of lean-burn engines. Currently, the predominant method employed for NOx removal is through selective catalytic reduction (SCR) using ammonia as a reducing agent. Typically, Fe- and Cu-exchanged CHA catalysts (Fe-SSZ-13 and Cu-SSZ-13) are used, but much less is known about Fe-SSZ-13 as compared to Cu-SSZ-13, which has been extensively characterized via experimental and computational techniques. In this work, density functional theory (DFT) calculations were performed to determine the most likely adsorption complexes that form within the six- or eight-membered rings (6MR or 8MR) of Fe-SSZ-13. We examine both Fe2+ (as [Fe(OH)]+) and Fe3+ (as [Fe(OH)]2+) as the possible active sites. Based on our results, the most energetically favorable site lies initially within the 6MR. However, with the addition of adsorbates, we find that the 8MR sites become more energetically favo... |
| Databáze: | OpenAIRE |
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