This work addresses spreading pressure dependence of real adsorbed solution theory (RAST) for mixed-gas adsorption equilibria using generalized Langmuir (gL) isotherm. Considering vacant sites as an integral part of competitive multicomponent adsorption on a constant adsorbent surface area, the gL isotherm properly accounts for surface heterogeneity and loading, adsorbate composition, and temperature dependence. We show the spreading pressure dependence of adsorbate activity coefficient expression in the RAST framework can be generated from the gL isotherm. The procedure is illustrated with a spreading pressure dependent adsorption nonrandom two-liquid activity coefficient model, and the results are validated for ten binary mixed-gas adsorption equilibria systems including two highly nonideal azeotropic systems.

这项工作使用广义朗缪尔 (gL) 等温线解决了混合气体吸附平衡的真实吸附溶液理论 (RAST) 的扩散压力依赖性。考虑到空位是恒定吸附剂表面积上竞争性多组分吸附的一个组成部分，gL 等温线正确地解释了表面异质性和负载、吸附物组成和温度依赖性。我们证明了 RAST 框架中吸附质活度系数表达式的扩散压力依赖性可以从 gL 等温线生成。该过程用扩散压力依赖性吸附非随机双液活度系数模型进行说明，并针对包括两个高度非理想共沸系统在内的十个二元混合气体吸附平衡系统验证了结果。