Bimetallic Co/Zn zeolitic imidazolate framework ZIF-67 supported Cu nanoparticles: An excellent catalyst for reduction of synthetic dyes and nitroarenes

In this study, a sub-class of microporous crystalline metal organic frameworks (MOFs) with zeolite-like configurations, i.e., zeolitic imidazolate frameworks of single node ZIF-67 and binary nodes ZIF-Co/Zn are used as the supports to develop Cu nanoparticles based nanocatalysts. Their catalytic activities are comparatively evaluated where Cu(x)@ZIF-Co/Zn exhibits better performances than Cu(x)@ZIF-67 in the reduction of synthetic dyes and nitroarenes. For instance, the Cu(0.25)@ZIF-Co/Zn catalyst shows an excellent reaction rate of 2.088 x 10(-2) s(-1) and an outstanding activity of 104.4 s(-1) g(cat)(-1) cat for the reduction of methyl orange. The same catalyst also performs an exceptional catalytic activity in the hydrogenation of p-nitrophenol to p-aminophenol with the activity of 216.5 s(-1) g(cat)(-1) . A synergistic role of unique electronic properties rising from the direct contact of Cu NPs with the bimetallic nodes ZIF-Co/Zn, higher surface area of support, appropriate Cu loading and maintainable micro porous frameworks with higher thermal and hydrolytic stability collectively enhances the catalytic activity of Cu (x)@ZIF-Co/Zn. Moreover, this catalyst shows excellent stability and recyclability, which can retain high conversion after reuse for 10 cycles.

Automated summary

In this study, microporous crystalline metal organic frameworks (MOFs) with zeolite-like configurations, ZIF-67 and ZIF-Co/Zn, are used as supports to develop Cu nanoparticles based nanocatalysts. The Cu(x)@ZIF-Co/Zn catalyst exhibits better performances in reducing synthetic dyes and nitroarenes compared to Cu(x)@ZIF-67. The exceptional catalytic activity is attributed to the synergistic role of unique electronic properties, higher surface area of support, appropriate Cu loading, and maintainable micro porous frameworks. Moreover, the catalyst shows excellent stability and recyclability, retaining high conversion after 10 cycles of reuse.