Abstract
The encapsulation of polyoxomolybdic cobalt (CoPMA) and polyoxomolybdic acid (PMA) within the Zr-based metal-organic frameworks (Zr-MOFs) of UiO-bpy (connected by 2,2′-bipyridine-5,5′-dicarboxylic acid linkers) and UiO-67 (connected by 4,4′-biphenyldicarboxylic acid linkers) has been achieved by direct solvothermal synthesis. Relatively high content of polyoxometalate (POM) clusters (ranging from 12 to 15 wt % loading) could be introduced to the cages of Zr-MOFs to form uniform hybrid composites of POM@Zr-MOFs. The catalytic properties of these composites were investigated for the olefins epoxidation with H2O2 or molecular O2 as oxidant. Among them, the catalyst CoPMA@UiO-bpy showed the highest catalytic activity and stability for cyclooctene epoxidation with H2O2 as oxidant and could also act as efficient heterogeneous catalyst for the oxidation of styrene and 1-octene with O2 as oxidant and tert-butyl hydroperoxide (t-BuOOH) as initiator. The excellent catalytic performance of the hybrid composite CoPMA@UiO-bpy should be mainly attributed to the uniform distribution of POM clusters within the size-matched cages of Zr-MOFs, as well as the multiple interactions between the CoPMA clusters and the functional groups (bipyridine and Zr-OH) located in the framework of UiO-bpy.
Original language | English |
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Pages (from-to) | 3624-3631 |
Number of pages | 8 |
Journal | ACS Sustainable Chemistry and Engineering |
Volume | 7 |
Issue number | 3 |
DOIs | |
Publication status | Published - 4 Feb 2019 |
Externally published | Yes |
Keywords
- Epoxidation
- Olefin
- Polyoxomolybdic cobalt
- Solvothermal synthesis
- Zr-MOF