Hydrothermal Synthesis of a Ce–Zr–Ti Mixed Oxide Catalyst with Enhanced Catalytic Performance for a NH3‑SCR Reaction

• Published in: Langmuir Vol. 37; no. 51; pp. 14823 - 14832
• Main Authors: Tan, Yifeng, Li, Fan, Zhao, Bing, Chen, Wenlin, Tian, Mengkui
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.12.2021
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.1c02597

A series of mesoporous CeZrTiO x catalysts were prepared by a facile hydrothermal method. Compared with CeTiO x catalysts synthesized under the same conditions, the catalytic activity and anti-SO2 performance of the Ce1Zr1TiO x catalyst are greatly improved, and at the gas hourly space velocity (GHSV) of 60 000 h–1, the NO x removal efficiency is maintained at 90% in the temperature range of 290–500 °C. The catalytic effect of ZrO2 on the Ce–Ti catalyst NH3-SCR activity was elucidated through a series of characterizations. The results revealed that the doping of Zr could significantly improve and optimize the structure of Ce–Ti catalysts. At the same time, due to the doping of Zr, the synergistic effect between Ce and Zr in the CeZrTiO x catalyst can effectively increase oxygen mobility, total acid content, and surface adsorbed oxygen species and lead to a larger pore volume. In addition, the introduction of ZrO2 made the transformation of Ce4+ into Ce3+ more obvious, and the 2Ce4+ + Zr2+ ↔ 2Ce3+ + Zr4+ reaction greatly improved the reducibility of Ce1Zr1TiO x . Among them, the improvement of SCR performance and H2O/SO2 tolerance is due to the electronic interaction between Zr and Ce.