The development of catalysts able to assist industrially important chemical processes is a topic of high importance. In view of the catalytic capabilities of small metal clusters, research efforts are being focused on the synthesis of novel catalysts bearing such active sites. Here we report a heterogeneous catalyst consisting of Pd₄ clusters with mixed-valence 0/+1 oxidation states, stabilized and homogeneously organized within the walls of a metal–organic framework (MOF). The resulting solid catalyst outperforms state-of-the-art metal catalysts in carbene-mediated reactions of diazoacetates, with high yields (>90%) and turnover numbers (up to 100,000). In addition, the MOF-supported Pd₄ clusters retain their catalytic activity in repeated batch and flow reactions (>20 cycles). Our findings demonstrate how this synthetic approach may now instruct the future design of heterogeneous catalysts with advantageous reaction capabilities for other important processes.

中文翻译：

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MOF驱动的负载钯簇的合成，具有对卡宾介导的化学反应的催化活性

能够辅助工业上重要的化学过程的催化剂的开发是非常重要的主题。考虑到小金属簇的催化能力，研究工作集中在合成具有这种活性位点的新型催化剂上。在这里，我们报告了一种非均相催化剂，该催化剂由具有混合价0 / +1氧化态的Pd ₄簇组成，在金属-有机骨架（MOF）的壁中稳定且均匀地组织。在卡宾介导的重氮乙酸酯反应中，所得的固体催化剂性能优于最新的金属催化剂，产率高（> 90％），周转率最高（达100,000）。此外，MOF支持的Pd ₄团簇在重复的间歇和流动反应（> 20个循环）中保持其催化活性。我们的发现表明，这种合成方法现在如何指导未来对具有重要反应能力的非均相催化剂的设计。