Nature of cerium on improving low-temperature hydrothermal stability of SAPO-34
来源期刊：JOURNAL OF RARE EARTHS2021年第5期
论文作者：Qingyun Wang Meiqing Shen Jianqiang Wang Chen Wang Jun Wang
文章页码：548 - 557
摘 要：To probe the function of Ce on enhancing low-temperature stability of SAPO-34,Ce/SAPO-34 with different Ce contents was prepared via one-pot method and further treated at 70℃ in 80% relative humidity for 24 h.The structural results prove that the one-pot synthesis is an effective way to introduce Ce（Ce <0.325 wt%） without influencing micro-structural and chemical composition.The lowtemperature hydrothermal stability of Ce/SAPO-34 is enhanced by Ce loading.More than 92% CHA structure and total acidity are maintained over 0.188 wt% Ce/SAPO-34,while only about 20% of that left on pure H/SAPO-34.As Ce exists as Ce3+at exchange sites on the surface of SAPO-34,the results of the linear relationship between protected surface acidity and structure/acidity conservation manifest that Ce3+ effectively hinders the structural collapse.This study provides new insight into surface acidity protection for solving the problem of low-temperature hydrothermal stability of SAPO-34.
Qingyun Wang1，Meiqing Shen1,2,3，Jianqiang Wang1，Chen Wang1,4，Jun Wang1
1. Key Laboratory for Green Chemical Technology of State Education Ministry,School of Chemical Engineering and Technology,Tianjin University2. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)3. State Key Laboratory of Engines,Tianjin University4. School of Environment and Safety Engineering,North University of China
摘 要：To probe the function of Ce on enhancing low-temperature stability of SAPO-34,Ce/SAPO-34 with different Ce contents was prepared via one-pot method and further treated at 70℃ in 80% relative humidity for 24 h.The structural results prove that the one-pot synthesis is an effective way to introduce Ce（Ce <0.325 wt%） without influencing micro-structural and chemical composition.The lowtemperature hydrothermal stability of Ce/SAPO-34 is enhanced by Ce loading.More than 92% CHA structure and total acidity are maintained over 0.188 wt% Ce/SAPO-34,while only about 20% of that left on pure H/SAPO-34.As Ce exists as Ce3+at exchange sites on the surface of SAPO-34,the results of the linear relationship between protected surface acidity and structure/acidity conservation manifest that Ce3+ effectively hinders the structural collapse.This study provides new insight into surface acidity protection for solving the problem of low-temperature hydrothermal stability of SAPO-34.
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