Metal organic framework‐capsulated CoCu nanoparticles for the selective transfer hydrogenation of nitrobenzaldehydes: engineering active armour by half‐way injection method

A novel armour-type composite of metal organic framework-capsulated CoCu nanoparticles with Fe3O4 core (Fe3O4@SiO2-NH2-CoCu@UiO-66) has been designed and synthesized by the half-way injection method, which successfully serves as an efficient and recyclable catalyst for the selective transfer hydrogenation. In this half-way injection approach, the pre-synthetic Fe3O4@SiO2-NH2-CoCu was injected into the UiO-66 precursors solution halfway through the MOF budding period. The formed MOF armour could play a role of providing momentous additional catalytic sites besides CoCu nanoparticles, protecting CoCu nanoparticles and improving the catalyst stability, thus facilitating the selective transfer hydrogenation of nitrobenzaldehydes into corresponding nitrobenzyl alcohols in high selectivity (99%) and conversion (99%) rather than nitro group reduction products. Notably, this method achieves the precise assembly of MOF-capsulated composite, and the ingenious combination of MOF and nanoparticles exhibits excellent catalytic performance in the selective hydrogen transfer reaction, implementing a "1+1>2" strategy in catalysis.