Thermochemical reactions of ammonium-exchanged Y zeolite and its derivatives
Thermochemical reactions of ammonium-exchanged Y zeolite and its derivatives
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DOI：
10.1016/0021-9517(70)90174-0
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发表时间：
1970-08
影响因子：
7.3
通讯作者：
A. P. Bolton;M. Lanewala
中科院分区：
文献类型：
--
作者：
A. P. Bolton;M. Lanewala
采用红外、离子交换、热重、差热分析等方法研究了氨交换Y的热分解。构成热分解的脱氨和脱羟基反应显示在很大的温度范围内发生，并且在相当程度上重叠。在375℃时，95%的氨交换Y （SiO2al2o3摩尔比为5）完全脱胺，25%的脱羟基作用已经发生。沸石脱羟基化所需温度随SiO2al2o3摩尔比的增加而升高，随铵交换程度的增加而降低。本研究表明，氨交换Y脱胺得到的中间体与Y矿酸处理得到的中间体是同一种。氨交换Y的重构可以通过在脱羟基发生的整个温度范围内加水来实现，然后再加水。
The thermal decomposition of ammonium-exchanged Y was studied using infrared, ion exchange, thermogravimetric, and differential thermal analyses. The deammination and dehydroxylation reactions constituting the thermal decomposition are shown to take place over large temperature ranges and overlap to a considerable extent. At 375 °C, the temperature at which a 95% ammonium-exchanged Y having a SiO2Al2O3molar ratio of 5 is completely deamminated, 25% dehydroxylation has already occurred. The temperature required to dehydroxylate the zeolite increases with increasing SiO2Al2O3molar ratio and decreases with increasing extent of ammonium exchange. This study indicates that the intermediate derived by the deammination of ammonium-exchanged Y is the same species as that obtained by the mineral acid treatment of sodium Y. The reconstitution of ammonium-exchanged Y may be realized by adding water back to the dehydroxylated form over the entire temperature range the dehydroxylation takes place, prior to ammonia addition.