In-situ One-Pot Synthesis of Ti/Cu-SSZ-13 Catalysts with Highly Efficient NH3-SCR Catalytic Performance as Well as Superior H2O/SO2 Tolerability.

Autor: Wan, Jie, Chen, Jiawei, Shi, Yijun, Wang, Yiyan, Liu, Yanjun, Zhang, Jin, Wu, Gongde, Zhou, Renxian
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Zdroj: Catalysis Surveys from Asia; Dec2022, Vol. 26 Issue 4, p346-357, 12p
Abstrakt: Series of Ti/Cu-SSZ-13 zeolite catalysts with variable Ti content were prepared via convenient in-situ one-pot synthesizing strategy. Systematic evaluations of the NH3-SCR catalytic performance over the obtained catalysts were conducted. Results show that Ti/Cu-SSZ-13 with appropriate Ti content (in the current work Ti0.81/Cu2.15-SSZ-13) could serve as capable candidate for NH3-SCR application, as it exhibits highly efficient catalytic activity with expanded operation temperature window width from 140 to 540 °C, nearly 100% N2 selectivity, as well as superior tolerability against water vapor and SO2. Further structural/physicochemical characterizations demonstrate that the obtained Ti/Cu-SSZ-13 catalysts possess well-crystallized characteristic chabazite (CHA) structure. Isolated Cu2+ and monomeric Ti4+ are recognized as the primary active species, as the former mainly contributes to SCR reaction at low temperatures, while the latter are conducive for improving the high temperature SCR activity. Ti over doping would result in partial destruction of the zeolite structure, occupation of Cu2+ cation sites and formation of surface aggregated TiOx, thus leading to unsatisfactory NH3-SCR performances. Moreover, formation of agglomerated CuOx species during hydrothermal ageing and blockage of surface active sites by sulfate species formed during SO2 pretreatment are considered responsible for activity deterioration in the tolerability tests. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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