Surface property and spatial confinement engineering for achieving Ru nanoclusters on O/N-doped hollow carbon towards enhanced hydrogen production

Supported metal nanoclusters (NCs) have become highly attractive in catalytic applications because of their maximum atom utilization with superior catalytic property. The main challenge in fabricating metal NC catalysts is their low binding strength with carriers, which induces transformation of metal NCs to large nanoparticles. In this study, a facile, effective, and eco-friendly synthetic strategy for O/N-doped hollow carbon (ONC) is developed through direct steaming commercial Vulcan carbon in nitric acid vapour. The strong binding strength between abundant O/N functional groups of hollow structure of carbon matrix and Ru precursors enables the production of highly dispersed Ru NCs on ONC (Ru/ONC). The achieved Ru/ONC with highly distributed Ru NCs (1.69 nm in diameter) exhibits a significant activity improvement for catalytic AB dehydrogenation compared with Ru/C without modification. High turnover frequencies of 556 and 1837 min-1 (with NaOH) are achieved under the optimal conditions, surpassing most of previous developed Ru catalysts. Homogenously distributed Ru NCs with rich surface-active sites and the O/N functional groups of hollow structured carbon induced fast mass transfer are responsible for the superior activity. The facile strategy shows great application prospects for the preparation of efficient supported metal catalysts by modifying the structure and surface properties of carbon carriers.