摘要
采用重量法研究了温度为423 K3、73 K、343 K和323 K时对二甲苯在Silicalite-1分子筛上的吸附和脱附行为。结果表明,温度为323 K和343 K时吸附等温线出现了两个吸附平台。根据吸附等温线计算了热力学参数(吸附等容热、吉布斯自由能变、熵变和吸附相熵)。随着吸附量的增大,吸附等容热增大,吸附的吉布斯自由能变稍有下降,吸附熵变逐渐增大,吸附相的熵逐渐减小,分子间的相互作用逐渐增强。对吸附和脱附动力学进行了研究,发现在吸附量大约为4 m.(u.c.)-1时,扩散系数出现了峰值。
Adsorption and desorption of p-xylene on Silicalite-1 at 423 K, 373 K, 343 K and 323 K were studied using intelligent gravimetric analyzer （IGA）. The results showed that the isotherms at temperatures of 323 K and 343 K had two adsorption plateaus. Adsorption heat, free enthalpy change, entropy change and entropy of adsorbed phase at different adsorbed quantity were calculated from the adsorption isotherms. With increase in adsorbed quantity, adsorption heat increased, free enthalpy change declined slightly, adsorption entropy increased, entropy of adsorbed phase decreased and interaction between the molecules increased. Kinetics for the adsorption and desorption were studied. A peak value for diffusion coefficient appeared at about 4 m·（u. c. ）^-1.
出处
《工业催化》
CAS
2005年第11期66-70,共5页
Industrial Catalysis
基金
国家自然科学基金(20476042)
