Copper Doping Promotion on Ce/CAC-CNT Catalysts with High Sulfur Dioxide Tolerance for Low-Temperature NH3–SCR
| Autor: | Xiaomi Meng, Lu Yao, Xia Jiang, Charles Q. Jia, Wenju Jiang, Pengchen Wang, Lin Yang |
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| Rok vydání: | 2021 |
| Předmět: |
Renewable Energy
Sustainability and the Environment General Chemical Engineering chemistry.chemical_element General Chemistry Redox Oxygen Catalysis law.invention chemistry.chemical_compound Adsorption chemistry law medicine Environmental Chemistry Calcination Lewis acids and bases Sulfur dioxide Nuclear chemistry Activated carbon medicine.drug |
| Zdroj: | ACS Sustainable Chemistry & Engineering. 9:987-997 |
| ISSN: | 2168-0485 |
| Popis: | The stumbling block to the ever-increasing need for improving air quality remains nitrogen oxides (NOₓ). The copper-introduced Ce/CAC-CNT (CuₓCe/CAC-CNTs) catalyst using the in situ-growth-prepared activated carbon and carbon-nanotube composite (CAC-CNT) carrier with high sulfur dioxide tolerance was successfully applied to low-temperature NH₃–SCR in this study. The findings indicate that the CuₓCe/CAC-CNTs obtained at a 0.2 Cu/Ce molar ratio and the calcination temperature of 450 °C showed the highest 100% NO conversion with 95.8% N₂ selectivity at 150 °C and 10 000 h–¹. The incorporation of Cu improved the Cu₀.₂Ce/CAC-CNTs in Lewis acid, lattice oxygen (31.99%), and Ce³⁺ (26.03%). The accelerated NH₃ adsorption on acid sites, the encouraging electron transfer by the Ce⁴⁺ + Cu⁺ ↔ Ce³⁺ + Cu²⁺ redox circle, and the more surface chemisorbed oxygen (Oᵦ) improved the catalytic activity of Cu₀.₂Ce/CAC-CNTs. The NH₃–SCR of Cu₀.₂Ce/CAC-CNTs largely follows the L–H mechanism, together with a certain degree of “Fast SCR.” The added Cu species effectively prevented surface SO₂ adsorption and oxidation, and the Cu₀.₂Ce/CAC-CNTs restored more than 94% SCR activity after 8 h of poisoning in 50 ppm SO₂ and 5 vol % H₂O. |
| Databáze: | OpenAIRE |
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