Theory for melting anomalies in adsorbate systems

Melting anomalies, observed in a variety of adsorbate systems such as N₂, Ar or CH₄ on TiO₂ and H₂O absorbed in coal, Al₂0₃, zeolite, or porous glass, are shown to be manifestations of the melting characteristics of small molecular clusters. The theoretical results show not only that melting is a continuous phenomenon for small aggregates, but that for clusters consisting of ten to twenty molecules, melting may commence at temperatures considerably lower than the bulk melting point. Comparison between the theory and experimental data yields excellent agreement.