Abstract

SSZ-13 zeolite was synthesized using four templates, and the synthesis conditions with choline chloride (CC) as template were optimized by dynamic stirring, fluoride-assisted and seed-assisted synthesis. Because the geometric dimensions of CC dimer (7.21 × 10.72 Å) and CHA cage (7.3 × 12 Å) matched closely, the crystallinity and specific surface area of sample synthesized using CC were higher than those of other samples (except for that of the sample synthesized using TMAdaOH). By adopting three improved methods, SSZ-13 samples with better crystallinity, higher specific surface area and more regular morphology could be synthesized in a shorter time (3–4 days). The sample prepared using fluoride-assisted method could achieve a similar crystallinity to the sample synthesized using TMAdaOH. The corresponding catalyst exhibited the best catalytic performance in the NH₃-SCR reaction, with 100% NO conversion from 150 to 550 °C. This performance was attributed to fluoride ions promoting the formation of CC dimers through charge attraction of SiF₆²⁻. Furthermore, by synthesis optimization, the more developed pore structure, stronger NH₃ adsorption capacity and lower CuO content of Cu-SSZ-13 were also important factors for the improved catalytic performance.

Graphic Abstract

中文翻译：

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针对NH 3 -SCR工艺优异性能的SSZ-13沸石有效合成策略。

摘要

用四个模板合成SSZ-13沸石，并通过动态搅拌，氟化物辅助和种子辅助合成优化了氯化胆碱（CC）为模板的合成条件。因为CC二聚体（7.21×10.72Å）和CHA笼（7.3×12Å）的几何尺寸紧密匹配，所以使用CC合成的样品的结晶度和比表面积要高于其他样品（样品除外）。 （使用TMAdaOH合成）。通过采用三种改进的方法，可以在更短的时间内（3-4天）合成具有更好的结晶度，更高的比表面积和更规则的形态的SSZ-13样品。使用氟化物辅助方法制备的样品可以实现与使用TMAdaOH合成的样品相似的结晶度。_3- SCR反应，在150至550°C时100％NO转化。该性能归因于氟离子通过SiF ₆ ^2-的电荷吸引促进CC二聚体的形成。此外，通过合成优化，Cu-SSZ-13的孔结构更发达，NH ₃吸附能力更强，CuO含量更低，也是提高催化性能的重要因素。

图形摘要