Molar entropies at 80 K of sub-monolayer nitrogen films adsorbed on graphite from heat capacity measurement

摘要: The heat capacity of nitrogen adsorbed on an exfoliated graphite (Grafoil GTA) has been measured between 3 and 80 K at surface coverages of [Formula: see text] The molar entropies are determined at 80 K. The effect of energetic heterogeneity of the graphite surface seems to be much less than that expected from the measurements of heats of adsorption. The isosteric heat of adsorption at zero coverage qst(0), for a hypothetical homogeneous graphite surface is estimated to be 9.8 kJ mol−1 at 80 K, which is in good agreement with that obtained from simulations performed at 75 K, 9.9 kJ mol−1.