Single-atom catalysts show a promising future in many reactions even though great challenges still remain such as facile synthesis and long stability. In this work, a single-atom Pd catalyst attached to a designed N₈ Lewis base species (Pd₁-N₈/CNT) is synthesized with cyclic voltammetry (CV) method. The catalyst demonstrates long stability and enhanced C₂H₄ selectivity in selective hydrogenation of acetylene at 40 °C. CV is carried out in a three-electrode setup with PdO/CNT as the working electrode in NaN₃ solution. HAADF-STEM confirms single-atom Pd sites are successfully isolated. XPS measurements and Bader charge calculations indicate N₈ is effectively synthesized on CNT substrate after CV treatment while single-atom Pd is stabilized by attaching to the end N of N₈. Acetylene-temperature programed desorption (C₂H₂-TPD) and density functional theory (DFT) calculations suggest C₂H₂ favors the π bonding on single Pd atom, while H₂ dissociates on the N atom (next to Pd) instead of conventionally on Pd. The synergistic effect favors C₂H₄ formation but prevents full hydrogenation of acetylene to C₂H₆. This work opens up a new perspective to design and synthesize more selective catalysts with isolated single-atom sites.

单原子催化剂在许多反应中都显示出有希望的未来，尽管仍然存在巨大的挑战，例如合成容易和长期稳定性。在这项工作中，通过循环伏安法（CV）合成了附着在设计的N ₈ Lewis碱物种（Pd ₁ -N ₈ / CNT）上的单原子Pd催化剂。该催化剂在40°C下乙炔选择性加氢中显示出长期稳定性和增强的C ₂ H ₄选择性。CV在三电极设置中以PdO / CNT作为工作电极在NaN ₃溶液中进行。HAADF-STEM确认成功分离了单原子Pd位点。XPS测量和Bader费用计算表明N ₈CV处理后，可在CNT基板上有效地合成Pn，同时通过连接到N ₈的N端来稳定单原子Pd 。乙炔程序升温脱附（C ₂ H ₂ -TPD）和密度泛函理论（DFT）计算表明，C ₂ H ₂倾向于单个Pd原子上的π键，而H _2则在N原子上解离（Pd旁边）而不是通常在Pd上。协同作用有利于C ₂ H _4的形成，但是阻止了乙炔完全氢化为C ₂ H ₆。这项工作为设计和合成具有孤立单原子位点的更具选择性的催化剂开辟了新的视角。