Heteroatoms doped iron oxide-based catalyst prepared from zinc slag for efficient selective catalytic reduction of NO.sub.x with NH.sub.3

• Published in: International journal of coal science & technology Vol. 11; no. 1
• Main Authors: Liang, Jiale, Zhang, Yaojun, Chen, Hao, Liu, Licai, He, Panyang, Wu, Lei
• Format: Journal Article
• Language: English
• Published: Springer 01-12-2024
• Subjects: Ferric oxide; Iron compounds; Nitrogen oxide
• ISSN: 2095-8293
• DOI: 10.1007/s40789-023-00634-0

Excessive emissions of nitrogen oxides from flue gas have imposed various detrimental impacts on environment, and the development of deNO.sub.x catalysts with low-cost and high performance is an urgent requirement. Iron oxide-based material has been explored for promising deNO.sub.x catalysts. However, the unsatisfactory low-temperature activity limits their practical applications. In this study, a series of excellent low-temperature denitrification catalysts (Ha-FeO.sub.x/yZS) were prepared by acid treatment of zinc slag, and the mass ratios of Fe to impure ions was regulated by adjusting the acid concentrations. Ha-FeO.sub.x/yZS showed high denitrification performance (> 90%) in the range of 180-300 °C, and the optimal NO conversion and N.sub.2 selectivity were higher than 95% at 250 °C. Among them, the Ha-FeO.sub.x/2ZS synthesized with 2 mol/L HNO.sub.3 exhibited the widest temperature window (175-350 °C). The excellent denitrification performance of Ha-FeO.sub.x/yZS was mainly attributed to the strong interaction between Fe and impurity ions to inhibit the growth of crystals, making Ha-FeO.sub.x/yZS with amorphous structure, nice fine particles, large specific surface area, more surface acid sites and high chemisorbed oxygen. The in-situ DRIFT experiments confirmed that the SCR reaction on the Ha-FeO.sub.x/yZS followed both Langmuir-Hinshelwood (L-H) mechanism and Eley-Rideal (E-R) mechanism. The present work proposed a high value-added method for the preparation of cost-effective catalysts from zinc slag, which showed a promising application prospect in NO.sub.x removal by selective catalytic reduction with ammonia.