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天然沸石中阳离子被氢离子置换后对水及甲醇的吸附量增加,与离子交换量有关。离子半径较大的阳离子被较小的阳离子取代,导致4.5孔径的微孔增多。沸石从气相中吸附水在相对压力低于0.85时,吸附-脱附等温线近似或完全重合。刚性沸石中,部分晶格可被水分子松开,晶体保持不变但晶体孔穴增大。由于沸石微孔扩张,脱附等温线与原先的吸附等温线有所不同。滞后环的产生是因沸石肿胀所致,即使脱附完全仍可保持肿胀;脱附至原始状态后若再行吸附,将沿脱附等温线进行。根据偏差统计分析,沸石吸附水测定比表面的方法是适用的。
Natural zeolite cation hydrogen ions after the replacement of water and methanol adsorption increased, and the amount of ion exchange. Cations with larger ion radii are replaced by smaller cations, resulting in an increase in micropores of 4.5 pore size. Adsorption of zeolite from the gas phase at a relative pressure below 0.85, the adsorption-desorption isotherm nearly or completely coincide. Rigid zeolites, part of the lattice can be released by water molecules, the crystal remains unchanged but the crystal cavity increases. As zeolite micropore expansion, desorption isotherm with the original adsorption isotherm is different. The hysteresis loop is caused by the swelling of the zeolite, which can maintain the swelling even if the desorption is complete. If the desorption is carried out after the desorption to the original state, it will proceed along the desorption isotherm. According to statistical analysis of deviations, the method of determining the specific surface of zeolite adsorbed water is suitable.