Isosteric enthalpies for hydrogen adsorbed on nanoporous materials at high pressures

摘要: A sound understanding of any sorption system requires an accurate determination the enthalpy adsorption. This is a fundamental thermodynamic quantity that can be determined from experimental data and its correct calculation extremely important for heat management in adsorptive gas storage applications. It especially relevant hydrogen storage, where porous regarded as competing alternative to more mature methods such liquid compressed gas. Among most common calculate isosteric enthalpies literature are virial equation Clausius–Clapeyron equation. Both have drawbacks, example, arbitrary number terms assumption ideal behaviour Although some researchers calculated adsorption using excess amounts adsorbed, it arguably applications may also thermodynamically consistent use absolute since Gibbs partition, not phase. In this paper virial, Clapeyron equations two materials—activated carbon AX-21 metal-organic framework MIL-101. shown these example materials only used at low coverage, hydrogen’s deviates high pressures. The require care, highly dependent on selecting appropriate parameters. systematic study different parameters was performed that, case, seems give better approximations exact than with 10 variable