Abstract：
Precise control over the size, species, and breakthrough of the activity-selectivity trade-off are great challenges for sub-nano non-noble metal catalysts. Here, for the first time, a \"multiheteroatom induced SMSI + in situ P activation\" strategy that enables high stability and effective construction of sub-2 nm metal sites for optimizing selective hydrogenation performance is developed. It is synthesized the smallest metal phosphide clusters (<2 nm) including from unary to ternary non-noble metal systems, accompanied by unprecedented thermal stability. In the proof-of-concept demonstration, further modulation of size and species results in the creation of a sub-2 nm site platform, directionally achieving single atom (Ni1), Ni1+metal cluster (Ni1+Nin), or novel Ni1+metal phosphide cluster synergistic sites (Ni1+Ni2Pn), respectively. Based on thorough structure and mechanism investigation, it is found the Ni1+Ni2Pn site is motivated to achieve electronic structure self-optimizing through synergistic SMSI and site coupling effect. Therefore, it speeds up the substrate adsorption-desorption kinetics in semihydrogenation of alkyne and achieves superior catalytic activity that is 56 times higher than the Ni1 site under mild conditions. Compared to traditional active sites, this may represent the highly effective integration of atom utilization, thermal stability, and favorable site requirements for chemisorption properties and reactivities of substrates.
摘要：
精确控制尺寸，物种,活性-选择性权衡的突破是亚纳米非贵金属催化剂面临的巨大挑战。这里,第一次,开发了“多杂原子诱导的SMSI原位P活化”策略，该策略可实现高稳定性和有效构建亚2nm金属位点，以优化选择性加氢性能。它是合成最小的金属磷化物簇（<2nm），包括从一元到三元非贵金属系统，伴随着前所未有的热稳定性。在概念验证演示中，尺寸和物种的进一步调节导致创建亚2nm站点平台，定向实现单原子(Ni1)，Ni1+金属簇(Ni1+Nin),或新的Ni1+金属磷化物簇协同位点（Ni1+Ni2Pn），分别。基于深入的结构和机制研究，发现Ni1Ni2Pn位点通过协同SMSI和位点耦合效应来实现电子结构的自优化。因此,它加快了炔烃半氢化中的底物吸附-解吸动力学，并在温和条件下实现了比Ni1位点高56倍的优异催化活性。与传统的活跃网站相比，这可能代表了原子利用的高度有效集成，热稳定性，以及对底物的化学吸附特性和反应性的有利场所要求。
