Catalytic hydrogenation is one of the backbones of the chemical industry. Controlling the reaction behaviour of the activated hydrogen species over oxide-supported metal catalysts is essential. Aside from the expected addition to substrates, the activated hydrogen species would also destroy the active structures. Here we show that, with the assistance of alkali cations, the atomically dispersed Ru(iii) on Al₂O₃ exhibits enhanced performance in the hydrogenation of a broad range of substrates. The alkali cations facilitate the hydrogenation mediated by heterolytic hydrogen species, which not only restrain the hydride species from migrating to interfacial oxygen, thus suppressing the reduction and aggregation of ruthenium, but also stabilize the negatively charged transition states and intermediates through enhanced Columbic attraction. Distinctively, an inverse H/D isotope effect related to H₂ splitting as the rate-determining step over the atomically dispersed ruthenium-catalysed hydrogenation is predicted and confirmed.

催化加氢是化学工业的骨干之一。在氧化物负载的金属催化剂上控制活化氢物种的反应行为至关重要。除了预期的底物添加之外，活化的氢物质还将破坏活性结构。在这里我们表明，借助碱金属阳离子，原子分散的Ru（iii）在Al ₂ O _3上在广泛的底物氢化中表现出增强的性能。碱金属阳离子促进了由杂氢原子介导的加氢，这不仅抑制了氢化物原子迁移至界面氧，从而抑制了钌的还原和聚集，而且还通过增强的哥伦布吸引力来稳定了带负电的过渡态和中间体。独特地，预测并证实了与H ₂分解有关的逆H / D同位素效应，该氢分解是原子分散的钌催化的氢化反应的速率确定步骤。