ИСТИНА

NMR spectroscopy of adsorbed organophosphorus probe molecules is a promising method for studying the acid properties of zeolite catalysts. According to the literature data, a number of such molecules has already been tested: trimethylphosphine (TMP), oxides of trimethylphosphine (TMPO) and its homologues such as tri-n-butyl- (TBPO) and tri-n-octyl- (TOPO) phosphine. However, most of the proposed techniques allow only a qualitative characterization of acidity in zeolites, as it is not possible to introduce a given number of probe molecules into the sample. Therefore, this study was aimed at developing an approach for the quantitative determination of acid sites in zeolites based on 31P MAS NMR spectroscopy.