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【目的】为开发高效、环保的低温脱硝催化剂，解决燃煤电厂低负荷运行时烟气温度无法满足SCR脱硝催化剂最佳反应温度的问题，提升NH3选择性催化还原(NH3-SCR)反应的低温活性及抗中毒性能。【方法】本文采用共沉淀法和湿浸渍法设计并制备Mo改性的Ce-Zr固溶体(CexZr1-xO2)催化剂(Mo/CexZr1-xO2)，通过X射线粉末衍射(X-ray diffraction,XRD)、氢气程序升温还原(H_2-temperature-programmed reduction,H_2-TPR)、NH3程序升温脱附(NH_3-temperature programmed desorption,NH_3-TPD)等表征手段分析催化剂的结构、氧化还原能力及酸位分布。【结果】研究表明，Ce与Zr形成立方萤石结构的固溶体，显著增强了催化剂的氧化还原能力与比表面积，而MoO3的引入提供了关键的酸位点，协同促进NH3吸附活化。其中，Mo/Ce0.5Zr0.5O2(Mo/C5Z5)催化剂表现出最优性能：在200～350℃内NO转化率>90%,N2选择性高，且在含200μL/L SO2与5%H2O的苛刻条件下仍保持80%以上活性，抗硫抗水性能显著优于传统钒基催化剂。【结论】该研究为开发高效、环保的低温脱硝催化剂提供了新策略，为解决燃煤电厂低负荷运行条件下脱硝催化剂最佳活性与反应温度不匹配的问题提供了新思路，未来需进一步优化性能及长期稳定性以适应复杂烟气环境。
Abstract：[Objective] In order to develop an efficient and environmentally friendly low-temperature denitration catalyst and solve the problem that the flue gas temperature cannot meet the optimal reaction temperature of SCR denitration catalyst during low-load operation of coal-fired power plants, the low-temperature activity and anti-poisoning performance of NH3 selective catalytic reduction(NH_3-SCR) reaction were improved. [Methods] Mo-modified Ce-Zr solid solution(CexZr1-xO2) catalysts(Mo/CexZr1-xO2) were designed and prepared via the coprecipitation method and wet impregnation method. Characterization techniques such as XRD, H_2-TPR, and NH_3-TPD were used to analyze the structure, redox capacity, and acid site distribution of the catalysts. [Results] The results show that the formation of a cubic fluorite-structured solid solution by Ce and Zr significantly enhances the redox capacity and specific surface area of the catalyst, while the introduction of MoO3 provides key acid sites that synergistically promote NH3 adsorption and activation. Among them, the Mo/Ce0.5Zr0.5O2(Mo/C5Z5) catalyst exhibits optimal performance: NO conversion > 90% in the temperature range of 200～350 ℃, high N2 selectivity, and maintains over 80% activity at 250 ℃ under harsh conditions containing 200 μL/L SO2 and 5% H2O. Its sulfur and water resistance is significantly superior to traditional vanadium-based catalysts. [Conclusion] This study provides a new strategy for the development of efficient and environmentally friendly low-temperature denitration catalysts, and provides a new idea for solving the problem of mismatch between the optimal activity of denitration catalysts and reaction temperature under low-load operation conditions of coal-fired power plants. In the future, it is necessary to further optimize performance and long-term stability to adapt to complex flue gas environments.
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基本信息:
DOI：10.19944/j.eptep.1674-8069.2025.05.011
中图分类号:TQ426;X773
引用信息:
[1]赵勇刚,蔡彦迪,杜顺鑫,等.Mo/Ce_x Zr_(1-x)O_2催化剂的协同调控及其低温NH_3-SCR活性及抗中毒性能研究[J].电力科技与环保,2025,41(05):803-810.DOI:10.19944/j.eptep.1674-8069.2025.05.011.
基金信息:
国家自然科学基金项目（22272077）