Ag-NPs embedded in two novel Zn 3 /Zn 5 -cluster-based metal-organic frameworks for catalytic reduction of 2/3/4-nitrophenol.

By utilizing symmetrical pentacarboxylate ligands, 3,5-di(2',5'-dicarboxylphenyl)benzoic acid (H5 L1) and 3,5-di(2',4'-dicarboxylphenyl)benzoic acid (H5 L2), two novel porous Zn-MOFs, [Zn5 (μ3 -H2 O)2 (L1)2 ]·3DMA·4H2 O (CTGU-3) and [Zn3 (μ3 -OH)L2(H2 O)3 ]·H2 O (CTGU-4) have been synthesized under solvothermal conditions. CTGU-3 and CTGU-4 exhibit 3D microporous frameworks with flu and dia topologies and possess unique secondary building units [Zn5 (μ3 -H2 O)2 (RCO2 )6 ] and [Zn3 (μ3 -OH)(RCO2 )3 ], respectively. Such porous systems create a unique space or surface to accommodate Ag nanoparticles (Ag NPs), which could efficiently prevent Ag NPs from aggregation and leaching. In this work, two new Ag@Zn-MOF composites, denoted as Ag@CTGU, have been successfully fabricated through solution infiltration, for the reduction of nitrophenol. Compared with CTGU-4, CTGU-3 shows enhanced catalytic efficiency toward the reaction when it is used as a catalyst support of Ag NPs. Moreover, gas sorption and luminescence properties of two compounds were also investigated.