It is of great importance to develop selective and stable metal catalysts for the aqueous levulinic acid hydrogenation, yet challenging. Herein, we report a yolk-structured sing atom catalyst (SAC) with amine-modified Ru-1/Fe3O4 core and periodic mesoporousorganosilica (PMO) shell, synthesized by a core-shell dual stabilization strategy. The Ru single atoms (0.76 wt%) are inserted into the oxygen vacan-cies of spheric Fe3O4, and stabilized by the amine groups from 1,6-hexanediamine. The hollow PMO sphere is hydrophobic, that affords a strong barrier for interior Ru-1/Fe3O4 core, and the shell mesopore (4.2 nm) along with the cavity enhances the porosity of the resultant catalyst. As expected, the amine promoted Ru-1/Fe3O4 core in the hollow PMO shell (denoted as N-Ru-1/Fe3O4@void@PMO), proves to be highly selective and stable for the aqueous levulinic acid (LA) hydrogenation under harsh conditions (pH approximate to 1), giving gamma-valerolactone (GVL), a biomass-derived platform molecule with wide applications in the preparation of renewable chemicals and liquid transportation fuels. The elaborately fabricated catalyst is highly efficient, delivering 98.9% of selectivity to GVL and 99.0% of LA conversion in acidic water. And a high turnover frequency of 1084 h(-1) is achieved and this catalyst can be cycled 7 times without apparent drop of GVL yield and LA conversion. The amine-stabilized Ru single sites, acid-resistant Fe3O4 circled by the hydrophobic shell, and the enhanced porosity of catalyst, are responsible for the excellent catalytic performance of N-Ru-1/Fe3O4@void@PMO in acidic water. (C) 2020 Elsevier Inc. All rights reserved.