Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo, Japan.
Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan.
Nat Chem. 2023 Jul;15(7):940-947. doi: 10.1038/s41557-023-01234-w. Epub 2023 Jun 8.
The surfaces of metal nanoclusters, including their interface with metal oxides, exhibit a high reactivity that is attractive for practical purposes. This high reactivity, however, has also hindered the synthesis of structurally well-defined hybrids of metal nanoclusters and metal oxides with exposed surfaces and/or interfaces. Here we report the sequential synthesis of structurally well-defined {Ag} nanoclusters in the cavity of ring-shaped molecular metal oxides known as polyoxometalates. The {Ag} nanoclusters possess exposed silver surfaces yet are stabilized both in solution and the solid state by the surrounding ring-shaped polyoxometalate species. The clusters underwent a redox-induced structural transformation without undesirable agglomeration or decomposition. Furthermore, {Ag} nanoclusters showed high catalytic activity for the selective reduction of several organic functional groups using H under mild reaction conditions. We believe that these findings will serve for the discrete synthesis of surface-exposed metal nanoclusters stabilized by molecular metal oxides, which may in turn find applications in, for example, the fields of catalysis and energy conversion.
金属纳米团簇的表面，包括其与金属氧化物的界面，表现出很高的反应活性，这在实际应用中很有吸引力。然而，这种高反应活性也阻碍了具有暴露表面和/或界面的金属纳米团簇和金属氧化物结构明确的混合体的合成。在这里，我们报告了在称为多金属氧酸盐的环状分子金属氧化物的腔中顺序合成结构明确的{Ag}纳米团簇。{Ag}纳米团簇具有暴露的银表面，但在溶液中和固态中均由周围的环状多金属氧酸盐稳定。这些团簇在没有不良团聚或分解的情况下经历了氧化还原诱导的结构转变。此外，{Ag}纳米团簇在温和的反应条件下，对使用 H 选择性还原几种有机官能团表现出高催化活性。我们相信这些发现将有助于通过分子金属氧化物稳定的表面暴露的金属纳米团簇的离散合成，这反过来可能在例如催化和能量转换等领域得到应用。
