The size and geometry of supported metal ensembles have a substantial influence on their catalytic efficacy and are pivotal in the design of effective heterogeneous catalysts. Here we developed a straightforward electronic and structural engineering strategy to create supported single atomic-layered, low-nuclearity palladium catalysts. This atomically dispersed Pd catalyst possesses unique synergistic geometric and electronic effects and nearly full metal availability to the reactant, exhibiting excellent catalytic activity (turnover frequency of 12480 h⁻¹) and yield (>99%) in the hydrogenation of levulinic acid to 1,4-pentanediol under mild conditions, a reaction of importance for conversion of biomass to renewable chemicals. Theoretical calculations reveal that the high catalytic activity results from the cooperation of adjacent Pd atoms, high d-band center, and strong electronic metal-support interactions, thus guaranteeing efficient activation of reactant and facilitating the subsequent ring-opening step. The present work sheds light on the elegant design of low-nuclearity metal cluster catalysts with structure sensitivity to maximize the catalytic efficiency at the atomic scale.

负载型金属整体的尺寸和几何形状对其催化效率有重大影响，并且在有效多相催化剂的设计中起着关键作用。在这里，我们开发了一种简单的电子和结构工程策略来创建支持的单原子层、低核钯催化剂。这种原子分散的 Pd 催化剂具有独特的协同几何和电子效应，对反应物几乎全金属可用性，表现出优异的催化活性（转换频率为 12480 h ^-1) 和在温和条件下将乙酰丙酸氢化为 1,4-戊二醇的产率 (>99%)，这是将生物质转化为可再生化学品的重要反应。理论计算表明，高催化活性源于相邻Pd原子、高d带中心和强电子金属-载体相互作用的协同作用，从而保证了反应物的有效活化并促进了后续的开环步骤。目前的工作阐明了具有结构敏感性的低核金属簇催化剂的优雅设计，以最大限度地提高原子尺度的催化效率。