In Situ S-Doping Engineering for Highly Efficient NH3-SCR over Metal-Free Carbon Catalysts: A Novel Synergetic Promotional Mechanism.
Environ Sci Technol
; 58(1): 371-380, 2024 Jan 09.
Article
en En
| MEDLINE
| ID: mdl-38146194
ABSTRACT
Cyclic desulfurization-regeneration-denitrification based on metal-free carbon materials is one of the most promising ways to remove NOx and SO2 simultaneously. However, the impact of S-doping induced by the cyclic desulfurization and regeneration (C-S-R) process on the selective catalytic reduction (SCR) is not well understood. Herein, it is demonstrated that the C-S-R process at 500 °C induces in situ S-doping with a significant accumulation of C-S-C structures. NOx conversion was dramatically enhanced from 18.95% of the original sample to 84.55% of the S-doped sample. Density functional theory calculations revealed that the C-S-C structure significantly regulates the electronic structure of the C atom adjacent to the ketonic carbonyl group, thereby significantly altering the NH3 adsorption configuration with superior adsorption capacity. Moreover, S-doping induces an extra electron transfer between the N atom of the NH3 molecule and the C atom of the carbon plane, thereby promoting the activation of NH3 over the ketonic carbonyl group with a reduced energy barrier. This study elucidates a synergetic promotional mechanism between the ketonic carbonyl group and the C-S-C structure for SCR, offering a novel design strategy for high-performance heteroatom-doped carbon catalysts in industrial applications.
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01-internacional
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MEDLINE
Asunto principal:
Carbono
/
Amoníaco
Idioma:
En
Revista:
Environ Sci Technol
Año:
2024
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Article