In Situ S-Doping Engineering for Highly Efficient NH 3 –SCR over Metal-Free Carbon Catalysts: A Novel Synergetic Promotional Mechanism

作者：Xiao Zhu, Jin Yuan, Yue Peng, Jianjun Chen, Xing Yuan, Junhua Li · 发表于：Environmental Science & Technology · 年份：2023 · DOI：10.1021/acs.est.3c07628 · 被引用次数：24 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Catalytic Processes in Materials Science、Nanomaterials for catalytic reactions

Cyclic desulfurization–regeneration–denitrification based on metal-free carbon materials is one of the most promising ways to remove NO x and SO 2 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. NO x 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 NH 3 adsorption configuration with superior adsorption capacity. Moreover, S-doping induces an extra electron transfer between the N atom of the NH 3 molecule and the C atom of the carbon plane, thereby promoting the activation of NH 3 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.