Adsorption Enthalpy Determination on Silica-Supported Metallic Nanoparticles

Abstract

A new specific method to measure adsorption enthalpy on supported metallic nanoparticles has been developed. This method is based on gas chromatography measurements, and it allows the calculation of adsorption enthalpies on metallic nanoparticles while neglecting the effect of the supporting particle. In this paper, we discuss the specific case of the adsorption of benzene on the surface of silica-supported gold nanoparticles. The results show a good correlation with similar values found in the literature.

Mass Transport of Volatile Molecules in Porous Materials: Evaporation–Condensation Phenomena Described by NMR Diffusometry

“…This results in the following expression for the apparent diffusion constant D normale = italicp normalL D normalL + italicp normalV_int D normalV_int + italicp normalV_ext D normalV_ext considering that italicp normalL = 1 − italicp normalV_ext − italicp normalV_int This latter expression is equivalent to neglecting any adsorption effects, which are, conversely, a known fact for aromatic molecules on silica. However, in light of the weak interaction of benzene with silica, surface diffusion is likely to contribute minimally to mass transport, particularly in the presence of fast-moving vapor-phase molecules.…”