Due to the high energy needed to break the N ≡ N bond (945 kJ mol⁻¹), a key step in ammonia production is the activation of dinitrogen, which in industry requires the use of transition metal catalysts such as iron (Fe) or ruthenium (Ru), in combination with high temperatures and pressures. Here we demonstrate a transition-metal-free catalyst—potassium hydride-intercalated graphite (KH_0.19C₂₄)—that can activate dinitrogen at very moderate temperatures and pressures. The catalyst catalyses NH₃ synthesis at atmospheric pressure and achieves NH₃ productivity (µmol_NH3 g_cat⁻¹ h⁻¹) comparable to the classical noble metal catalyst Ru/MgO at temperatures of 250–400 °C and 1 MPa. Both experimental and computational calculation results demonstrate that nanoconfinement of potassium hydride between the graphene layers is crucial for the activation and conversion of dinitrogen. Hydride in the catalyst participates in the hydrogenation step to form NH₃. This work shows the promise of light metal hydride materials in the catalysis of ammonia synthesis.

由于破坏 N ≡ N 键所需的高能量 (945 kJ mol ^-1 )，氨生产中的关键步骤是二氮的活化，这在工业中需要使用过渡金属催化剂，例如铁 (Fe) 或钌 (Ru)，与高温和高压相结合。在这里，我们展示了一种不含过渡金属的催化剂——氢化钾插层石墨 (KH _0.19 C ₂₄ )——它可以在非常适中的温度和压力下激活二氮。该催化剂在大气压下催化NH _{3合成并实现NH 3}产率（µmol _NH3 g _cat ^-1  h ^-1) 在 250–400 °C 和 1 MPa 的温度下与经典的贵金属催化剂 Ru/MgO 相当。实验和计算结果都表明，石墨烯层之间氢化钾的纳米限制对于二氮的活化和转化至关重要。催化剂中的氢化物参与氢化步骤以形成NH ₃。这项工作显示了轻金属氢化物材料在氨合成催化中的前景。