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 Ru₁/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 vacancies 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 Ru₁/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 Ru₁/Fe₃O₄ core in the hollow PMO shell (denoted as N-Ru₁/Fe₃O₄@void@PMO), proves to be highly selective and stable for the aqueous levulinic acid (LA) hydrogenation under harsh conditions (pH ≈ 1), giving γ-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-Ru₁/Fe₃O₄@void@PMO in acidic water.

开发用于乙酰丙酸水溶液加氢的选择性和稳定的金属催化剂是非常重要的，但是具有挑战性。在本文中，我们报道了一种通过胺-壳双重稳定化策略合成的，具有胺改性的Ru ₁ / Fe ₃ O ₄核和周期性介孔有机硅（PMO）壳的蛋黄结构单原子催化剂（SAC）。Ru单原子（0.76 wt％）插入到球形Fe ₃ O ₄的氧空位中，并由1,6-己二胺中的胺基稳定。中空的PMO球是疏水的，为内部Ru ₁ / Fe ₃ O ₄提供了强大的屏障核和壳中孔（4.2 nm）以及空腔增强了所得催化剂的孔隙率。正如预期的那样，中空PMO壳中的胺促进的Ru ₁ / Fe ₃ O ₄核（表示为N-Ru ₁ / Fe ₃ O ₄ @ void @ PMO）对乙酰丙酸水溶液具有高度的选择性和稳定性。 （LA）在苛刻条件下（pH≈1）进行氢化，得到γ-戊内酯（GVL），这是一种生物质衍生的平台分子，在制备可再生化学品和液体运输燃料中具有广泛的应用。精心制作的催化剂具有很高的效率，在酸性水中对GVL的选择性为98.9％，对LA的转化率为99.0％。并具有1084小时的高周转频率达到^-1，并且该催化剂可以循环7次而GVL产率和LA转化率没有明显下降。胺稳定的Ru单点，疏水壳环绕的耐酸Fe ₃ O ₄以及增强的催化剂孔隙率，是N-Ru ₁ / Fe ₃ O ₄ @ void @ PMO在甲醇中优异的催化性能的原因。酸性水。