It is desirable to design non-precious metal nano-catalysts with high stability and catalytic performance for fine chemicals production. This work reports a method for the preparation of cobalt metal and cobalt oxide cores confined within nanoporous nitrogen-doped hollow carbon capsules. Core-shell structured Zn/Co-ZIF@polymer materials are fabricated through the facile coating polymer strategy on the surface of zeolitic imidazolate frameworks (ZIF). Subsequently, hydrothermal treatment and confined pyrolysis was used to prepare a series of ZnnCo5-nOx@carbon particles. Advanced Science, 2019, 6, in press (Corresponding author)
The result shows that the strong interaction between the cobalt nanoparticles and the surrounding carbon shell are greatly enhanced by the presence of Zn within the Co structure, which provide positive synergistic effects and serve to better disperse the Co particles. Moreover, the specific surface area and Co particle size have been optimized through finely tuning the original Zn content in ZIF particles, thus enhancing overall catalytic activity. The yolk-shell structured Zn4Co1Ox@carbon hollow capsules were shown to be a highly active and selective catalyst (selectivity >99%) for hydrogenation of nitrobenzene to aniline. Furthermore, Zn4Co1Ox@carbon hollow particles show superior catalytic stability, and no deactivation after 8 cycles of reaction. The hollow Co-CoOx@N-C capsules may shed the light for green and sustainable catalytic process for fine chemicals production.
