<p>Nickel-based catalysts show potential for the hydrogenation of styrene under mild conditions, but their active metallic sites are susceptible to oxidation during storage and handling, leading to severe deactivation, which limits their practical application. Herein, through a surface-modification strategy, we developed a Cr-modified Ni catalyst featuring a vacancy-rich NiCr₂O₄ layer, in which the oxygen vacancies capture and confine oxygen at the surface, preventing the oxidation of the metallic Ni⁰ core. The optimized Ni₃Cr₁@C catalyst achieves &gt; 99.9% ethylbenzene yield in styrene hydrogenation under mild conditions. It retains full activity after thermal oxidation at 150&#xa0;°C, whereas the unmodified Ni@C catalyst loses over 93% of its activity. Furthermore, the catalyst maintains &gt; 99.9% yield after six months of storage in ambient air, in stark contrast to the ~ 50% activity loss observed for the unmodified counterpart. This work provides a design principle for developing oxidation-resistant, non-noble metal catalysts that combine high activity with long-term stability.</p> Graphical Abstract <p></p>