Abstract Carbon-based materials are attractive in heterogeneous catalysis. In addition to be an ideal support for catalytic active species, carbon can form a protecting layer for non-noble metal nanoparticles (NPs) to prevent them from being oxidized. However, the synthesis of carbon supported non-noble metal NPs, with an even distribution of these transition metal NPs coated by a carbon shell, is still challenging. In this work, carbon supported metallic Co NPs coated by a graphitic carbon layer (C/Co@C) was successfully synthesized via calcinating of Co-MOF-74 at 1000 °C. The highly selective semi-hydrogenation of aromatic alkynes with NaBH4 to produce aromatic alkenes was realized over the as-obtained C/Co@C, in which the graphitic carbon layer acts like a “one-way valve” to allow BH4− to flow through, while preventing the larger size aromatic alkyne from entering the carbon shell to avoid its excessive hydrogenation. This work highlights the important role of using MOFs as precursor to prepare stable supported metal NPs for heterogeneous catalysis.

中文翻译：

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MOF 衍生的 C/Co@C 具有“单向阀”状石墨碳层，用于芳香炔烃的选择性半氢化

摘要 碳基材料在多相催化方面具有吸引力。除了作为催化活性物质的理想载体外，碳还可以为非贵金属纳米粒子 (NP) 形成保护层，以防止它们被氧化。然而，碳负载的非贵金属纳米颗粒的合成，这些过渡金属纳米颗粒的均匀分布被碳壳包覆，仍然具有挑战性。在这项工作中，通过在 1000°C 下煅烧 Co-MOF-74，成功合成了由石墨碳层 (C/Co@C) 包覆的碳负载金属 Co NPs。在所获得的 C/Co@C 上实现了芳香炔烃与 NaBH4 的高度选择性半氢化以生产芳香烯烃，其中石墨碳层充当“单向阀”以允许 BH4− 流过, 同时防止较大尺寸的芳烃进入碳壳，避免其过度氢化。这项工作强调了使用 MOF 作为前体制备稳定的负载金属纳米颗粒用于多相催化的重要作用。