considerable current interest. The hydrolysis of the nerve-agent simulant methylparaoxon,
as catalyzed by UiO-66 and UiO-67, was examined as a function of pH. Surprisingly, even
though typical phosphate–ester hydrolysis mechanisms entail nucleophilic attack of the
simulant by aqueous hydroxide, the rate of hydrolysis accelerates as the solution pH is
lowered. The unexpected behavior is attributed to a pH-dependent composition change …