Cation/proton interactions and acid strengths in salts of 12-tungstophosphoric acid prepared from 1A, 1B and 3B monovalent cations

Abstract

The substitution of the protons in 12-tungstophosphoric acid by 1A, 1B and 3B monovalent cations leads to increases in surface area, the introduction of micropore structures and alterations in the interactions experienced by the protons, as well as the expected decreases in the concentration of protons. The resultant changes in the distribution of acidic strengths and the effect of changes in the preparative stoichiometry and the nature of the cation have been assessed from proton MAS NMR and NH3 TPD measurements and correlated with the catalytic activities in the dehydration of 1-, 2- and tert-butanol on stoichiometric and nonstoichiometric compositions of the aforementioned solids.