Vanadium Catalyst on Isostructural Transition Metal, Lanthanide, and Actinide Based Metal–Organic Frameworks for Alcohol Oxidation

The understanding of the catalyst–support
interactions has
been an important challenge in heterogeneous catalysis since the supports
can play a vital role in controlling the properties of the active
species and hence their catalytic performance. Herein, a series of
isostructural mesoporous metal–organic frameworks (MOFs) based
on transition metals, lanthanides, and actinides (Zr, Hf, Ce, Th)
were investigated as supports for a vanadium catalyst. The vanadium
species was coordinated to the oxo groups of the MOF node in a single-ion
fashion, as determined by single-crystal X-ray diffraction, diffuse
reflectance infrared Fourier transform spectroscopy, and diffuse reflectance
UV–vis spectroscopy. The support effects of these isostructural
MOFs were then probed using the aerobic oxidation of 4-methoxybenzyl
alcohol as a model reaction. The turnover frequency was found to be
correlated with the electronegativity and oxidation state of the metal
cations on the supporting MOF nodes, highlighting an important consideration
when designing catalyst supports.