Synthesis, structural characterization, and catalytic performance of a vanadium-based metal-organic framework (COMOC-3)

摘要

A vanadium 2,6-naphthalenedicarboxylate, V ~(III)(OH)(O _2C-C _(10)H _6-CO _2)·H _2O, denoted as COMOC-3as (COMOC = Center for Ordered Materials, Organometallics and Catalysis, Ghent University), has been synthesized under hydrothermal conditions by means of both a solvothermal and a microwave synthesis procedure. The structure shows the topology of an aluminium 2,6-naphthalenedicarboxylate, the so-called MIL-69 (MIL = Materials of the Institute Lavoisier). After calcination at 250 °C in air, the V ~(III) center was oxidized to V ~(IV) with the structure of V ~(IV)O(O _2C-C _(10)H _6-CO _2) (COMOC-3). The oxidation process was verified by cyclic voltammetry and EPR spectroscopy. The crystallinity was investigated by variable-temperature XRD. The title compound is stable against air and moisture. The catalytic performance of COMOC-3 was examined in the liquid-phase oxidation of cyclohexene. COMOC-3 exhibited similar catalytic performance to MIL-47 [VO(O _2C-C _6H _4-CO _2)]. The compound is reusable and maintains its catalytic activity through several runs.