Monodispersed ultrafine bimetallic palladium–cobalt alloy nanoparticles (Pd_xCo_y) are prepared and immobilized on hollow carbon capsules (HCCs). Studies on the effect of metal composition on the catalytic activity of the Pd_xCo_y reveal that the nanoparticulate alloy with the atomic composition of Pd₃₆Co₆₄ is more active than the Co and Pd monometallic nanoparticles in the transfer hydrogenation of carbonyl compounds. The composition of the catalyst and its alloy formation are extensively characterized, and a variety of ketones and aldehydes are hydrogenated successfully with excellent yield and high turnover number (TON), displaying the ability of the synthesized ultrafine Pd₃₆Co₆₄ bimetallic nanoalloy to attain and retain both high catalytic activity and stability. This catalytic system is heterogeneous, stable and does not require additives for activation. Other advantages include milder reaction conditions (does not use gaseous hydrogen), low metal content (0.17 mol %) for a catalytic transfer hydrogenation reaction, functional group tolerance, environmentally benign nature, and reusability.

中文翻译：

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中空碳胶囊上的超细双金属PdCo合金纳米颗粒：羰基化合物转移加氢的高效多相催化剂

制备了单分散的超细双金属钯-钴合金纳米颗粒（Pd _x Co _y），并将其固定在中空碳囊（HCC）上。对金属成分对Pd _x Co _y催化活性的影响的研究表明，在羰基化合物的转移加氢反应中，具有Pd ₃₆ Co ₆₄原子组成的纳米颗粒合金比Co和Pd单金属纳米颗粒具有更高的活性。广泛地表征了催化剂的组成及其合金形成，成功地以优异的收率和高周转率（TON）对多种酮和醛进行了氢化，显示了合成超细钯的能力。₃₆ Co ₆₄双金属纳米合金可实现并保持高催化活性和稳定性。该催化体系是多相的，稳定的，不需要用于活化的添加剂。其他优点包括较温和的反应条件（不使用气态氢），催化转移氢化反应的低金属含量（0.17 mol％），官能团耐受性，环境友好性和可重复使用性。