Abstract
High-resolution 13C and 1H NMR measurements on methyl acrylate adsorbed on silica and TiCl4-modified silica are reported. In both cases, samples with methyl acrylate adsorbed at equilibrium pressures of 38 or 2 Torr, then desorbed under vacuum have been studied. NMR spectra of both nuclei show clearly the adsorption of the methyl acrylate on unmodified silica and on the TiCl4-modified silica. Our results indicate the existence of two adsorbed species which demonstrates the existence of two types of acid sites on the TiCl4-modified silica. We also characterized the effect of adsorption on the methyl acrylate molecules.