Enhanced NO x Catalytic Reduction by NH 3 over Polymeric Sulfur Species in CeO 2 via Tailoring Ce–O Bonds

作者：Zehui Huang, Ziyi Fan, Zirui Yu, Ruihua Wang, Jingfang Sun, Xiuwen Wang, Weixin Zou, Lin Dong · 发表于：Inorganic Chemistry · 年份：2025 · DOI：10.1021/acs.inorgchem.5c03976 · 被引用次数：1 · 研究领域：Catalytic Processes in Materials Science、Gas Sensing Nanomaterials and Sensors、Advanced Photocatalysis Techniques

Sulfate-modified CeO 2 is one of the effective routes to improving the performance of NH 3 –SCR; however, tailoring sulfur species and their effect on the Ce–O bond and NO x removal remains challenging. Herein, we rationally designed an excellent sulfate-modified ceria-based NH 3 –SCR catalyst by tuning the sulfate species to tailor chemical bonds in CeO 2 . NO x conversion was dramatically enhanced from 40% (conventional sulfuric acid impregnated CeO 2 –S catalyst) to 100% of the synthesized CeO 2 -TDC at 250 °C. By using Ce L 3 -edge XANES with various characterizations and density functional theory calculations, it was found that, in addition to the sulfate species in CeO 2 –S and CeO 2 -TDC, the polymeric state sulfate was also observed in CeO 2 -TDC, which redistributed the electron density between Ce sulfate and reduced the Ce–O bond length. Moreover, the reaction processes of NH 3 to NH 4 + /*NH 2 and NO to monodentate nitrate were more facilitated on CeO 2 -TDC via the synergistic interactions of rich Lewis acidic Ce 4+, Brønsted acidic S–OH, and enhanced redox, thus achieving the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) pathways, whereas only the E–R mechanism was on the conventional CeO 2 –S. This work provides a novel strategy for designing highly efficient sulfate-modified NH 3 –SCR catalysts.