Saturation properties of a supercritical gas sorbed in nanoporous materials

摘要: The description of experimental gas adsorption data in terms an accurate model is key to understand the mechanism and its limits. As a basic feature such should predict correctly conditions under which saturation occurs. However, absence bulk condensation properties for supercritical adsorbate this matter remains open discussions. In study, decreasing region excess hydrogen isotherms measured down 50 K used determine adsorbed phase volume, density pressure corresponding saturation. method developed these measurements addresses challenges very low temperature at high pressure. Therefore, modifications specially made cryostat conjunction with Sievert apparatus reach stability (±10 mK) 40 are presented. approach implemented on novel nanoporous materials UMCM-1 NOTT-112 over 50–77 0–40 bar. derived found be consistent Dubinin–Astakhov model. Importantly, volume also compares well pore obtained from Ar porosimetry. provide physical basis calculate absolute enthalpies, project ultimate capacity conceptual material maximized specific surface area. present findings additional evidence that common view adsorption, it assumed no liquid formed only possible involves monolayer coverage, does not hold many materials.