Determination of the enthalpy of adsorption of hydrogen in activated carbon at room temperature

摘要: Abstract The development of high-performance materials for hydrogen storage by adsorption requires detailed understanding the adsorbate-adsorbent interactions, e.g., enthalpy ΔH, which measures interaction strength. determination ΔH a weakly adsorbing gas such as in carbonaceous porous material is difficult experimentally, normally requiring measuring two cryogenic isotherms. Here we demonstrate calculation based on ca. room temperature isotherms at 273 K and 296 K using Clausius-Clapeyron equation. This an estimation volume adsorbed film (~40%, ~12% total pore 77 K, 296 K, respectively) obtained from fits excess to Ono-Kondo model with auxiliary use fixed point corresponding saturation density (estimated 100 ± 20 g/L) appears be remarkably sample independent, i.e., property adsorbate. calculated ΔH = 8.3 ± 0.4 kJ/mol excellent agreement low-coverage ΔH. methodology hereby proposed facilitates reliable calculations temperatures weakly-adsorbing gases.