摘要
本文探讨了γAlF3的热稳定性和酸性以及活性组分Cr3+含量与活性的关系.考察了研制的AlF3基催化剂的活性、稳定性及再生性,并对催化剂反应前后的结构进行比较.结果表明,催化剂的强酸中心是HCFC133a氟化生成HFC134a的活性中心,催化剂晶格的氟离子参与了氟氯交换反应.AlF3基催化剂具有高的活性和稳定性,在350℃,经2400h连续运行后,催化剂的晶相结构及比表面积未发生明显的变化.催化剂有较高的热稳定性,在400℃反应800h催化剂仍具有一定的活性(30%).
Thermal stability and acidity of γ AlF 3, the effect of active component of Cr 3+ in the catalysts on their activity were investigated. The activity, stability and regeneration properties of AlF 3 based catalysts, and the change of structure of the catalysts before and after reaction are presented in this paper. It is suggested that the site of strong acidity is active centre for reaction of HCFC 133a with HF to form HFC 134a and fluoride ion in the catalyst lattice participates in F/Cl exchange reaction. The AlF 3 based catalyst exhibits good activity and stability, and its surface area and crystalline phase doesnt change after continuous run for 2400 h at 350℃. The catalyst exhibits higher thermal stability. It possesses a certain activity after reacting for 800 h at 400℃. The catalyst deactivated by coking can be regenerated by introducing air or a mixture of air and HF at 350℃.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1997年第5期388-391,共4页
基金
国家自然科学基金
关键词
四氟乙烷
氟化铬
HFC-134A
铬催化剂
Tetrafluoroethane, Aluminum fluoride, Chromic fluoride, Fluoride catalyst, Activity, Stability