Co–Cu Nanoparticles: Synthesis by Galvanic Replacement and Phase Rearrangement during Catalytic Activation

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• 作者：Raquel Nafria ; Aziz Genç ; Maria Ibáñez ; Jordi Arbiol ; Pilar Ramírez de la Piscina ; Narcís Homs ; Andreu Cabot
• 刊名：Langmuir
• 出版年：2016
• 出版时间：March 8, 2016
• 年：2016
• 卷：32
• 期：9
• 页码：2267-2276
• 全文大小：780K
• ISSN：1520-5827

文摘

The control of the phase distribution in multicomponent nanomaterials is critical to optimize their catalytic performance. In this direction, while impressive advances have been achieved in the past decade in the synthesis of multicomponent nanoparticles and nanocomposites, element rearrangement during catalyst activation has been frequently overseen. Here, we present a facile galvanic replacement-based procedure to synthesize Co@Cu nanoparticles with narrow size and composition distributions. We further characterize their phase arrangement before and after catalytic activation. When oxidized at 350 °C in air to remove organics, Co@Cu core–shell nanostructures oxidize to polycrystalline CuO-Co₃O₄ nanoparticles with randomly distributed CuO and Co₃O₄ crystallites. During a posterior reduction treatment in H₂ atmosphere, Cu precipitates in a metallic core and Co migrates to the nanoparticle surface to form Cu@Co core–shell nanostructures. The catalytic behavior of such Cu@Co nanoparticles supported on mesoporous silica was further analyzed toward CO₂ hydrogenation in real working conditions.