Evaluation of Brønsted acidity and proton topology in Zr- and Hf-based metal–organic frameworks using potentiometric acid–base titration

Potentiometric acid–base titration is introduced as a method to evaluate pK_a values (Brønsted acidity) of protons present in the nodes of water stable Zr₆- and Hf₆-based metal–organic frameworks (MOFs), including UiO-type MOFs, NU-1000, and MOF-808.