MOF-on-MOF-derived core-shell structural Co/N co-doped porous carbon supported ultrafine Ru nanoparticles for boosting hydrogen evolution

Abstract

The development of efficient and cost-effective heterogeneous catalysts is crucial for promoting hydrogen production from ammonia borane (AB) hydrolysis. In this study, a MOF-on-MOF core-shell structure (ZIF-67@MOF-74) with a regular dodecahedral morphology was developed and then converted into a core-shell Co/N co-doped porous carbon (NC₁@NC₂) via a one-step carbonization process. Subsequently, ruthenium nanoparticles (Ru NPs) were uniformly dispersed on the heterogeneous interfaces of this core-shell structural carrier, creating a unique sandwich-like configuration, NC₁@Ru@NC₂. The interaction at the heterogeneous interface enhances the charge transfer and modulates the interfacial charge state, which not only firmly anchors the Ru NPs but also precisely optimizes their electronic structure. The core-shell design can further improve the dispersion and protection of Ru NPs, leading to a significant increase in the exposed metal site density (EMS). Therefore, the resulting catalyst demonstrates excellent catalytic activity and stability in AB hydrolysis, with an initial turnover frequency (TOF) of 408.9 min^–1 at 25 °C and 70.9% activity retention after ten cycles. This innovative catalyst preparation approach achieves Ru-based catalysts with core-shell structure, which provides a promising strategy for developing high-performance catalysts for AB hydrolysis with enhanced cycling stability.