The synergistic effects between Ce and Cu in CuyCe1−yW5Ox catalysts for enhanced NH3-SCR of NOx and SO2 tolerance

• Published in: Catalysis science & technology 2019-01, Vol.9 (3), p.718-730
• Main Authors: Jian-Wen, Shi, Wang, Yao, Duan, Ruibin, Chen, Gao, Wang, Baorui, He, Chi, Niu, Chunming
• Format: Article
• Language: eng ; jpn
• Subjects: Ammonia; Catalysis; Catalysts; Cerium; Chemical synthesis; Copper; Manganese; Metal oxides; Nitrogen oxides; Selective catalytic reduction
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c8cy01949e

Manganese-based metal oxides are promising catalysts for the NH3-SCR (selective catalytic reduction) of NOx at low temperatures. However, manganese-based catalysts usually exhibit poor SO2 and H2O tolerance. In order to overcome the fatal shortcoming, non-manganese-based CuyCe1−yW5Ox catalysts (y = 0, 0.4, 0.5, 0.6, 1.0) are synthesized successfully by a standard co-precipitation method, and the catalytic performances of these catalysts are tested by the NH3-SCR of NOx. The results show that there are synergistic effects between Cu and Ce, which affect the CuyCe1−yW5Ox catalysts in many aspects, such as the specific surface area, the surface contents of Ce3+ and Cu2+, the reductive strength and the amount of weak and strong acid sites on the surface. Moreover, the synergistic effects also have an impact on the de-NOx mechanism of CuyCe1−yW5Ox catalysts, and finally decide their catalytic performances. Among all the CuyCe1−yW5Ox catalysts, the Cu0.5Ce0.5W5Ox catalyst shows the best catalytic de-NOx performance and good tolerance to SO2 and H2O poisoning. This work may provide a suggestion for the design of non-manganese-based SCR catalysts with the desired de-NOx performance and good SO2 tolerance by making use of the synergistic effects between different metal oxides.