A new method for the NMR-spectroscopic measurement of the deprotonation energy of surface hydroxyl groups in zeolites

A new 1 H MAS NMR-spectroscopic method for the determination of the deprotonation energy Δ E DP of surface hydroxyl groups in zeolites is described. This method is based on the measurement of the induced 1 H NMR chemical shift Δδ caused by the interaction between the surface hydroxyl groups and weakly basic probe molecules such as C 2 Cl 4 or CO. The new 1 H MAS NMR-spectroscopic method is compared with the formerly established methods based on the measurement of the induced wavenumber shift Δν of the O−H stretching vibration caused by the adsorption of weakly basic probe molecules [1] or on the measurement of the 1 H NMR chemical shift δ H in activated samples [2,3].