Thermally induced migration of a polyoxometalate within a metal–organic framework and its catalytic effects

Abstract

The polyoxometalate (POM), H₃PW₁₂O₄₀, was postsynthetically incorporated into the metal–organic framework (MOF), NU-1000. The POM@MOF composite, PW₁₂@NU-1000, was activated under mild conditions, resulting in a material whose diffraction pattern and spectroscopic properties differ from the same material heated at elevated temperatures. These discrepancies, corroborated by difference envelope density analyses, were attributed to the POM residing either in the mesoporous or microporous channels of NU-1000. As a testament to the importance of catalyst accessibility, the POM's locational change also induced a change in the composite's rate and selectivity toward oxidizing 2-chloroethyl ethyl sulfide.