Metal–Organic Framework‐Encapsulated CoCu Nanoparticles for the Selective Transfer Hydrogenation of Nitrobenzaldehydes: Engineering Active Armor by the Half‐Way Injection Method

A novel armor‐type composite of metal–organic framework (MOF)‐encapsulated CoCu nanoparticles with a 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 precursor solution halfway through the MOF budding period. The formed MOF armor could play a role of providing significant 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 a MOF‐encapsulated 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. Greater than the sum of its parts: An armor‐type composite of metal–organic framework (MOF)‐encapsulated CoCu nanoparticles with a Fe3O4 core was designed and synthesized by a novel half‐way injection method. The resulting Fe3O4@SiO2‐NH2‐CoCu@UiO‐66 serves as an efficient and recyclable catalyst for the selective transfer hydrogenation of nitrobenzaldehydes in high selectivity (99 %). This novel method and ingenious combination of MOF and nanoparticles implements a “1+1>2” strategy in catalysis.