title: Co-Cu Nanoparticles: Synthesis by Galvanic Replacement and Phase Rearrangement during Catalytic Activation.
abstract: 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.
authors.affiliation: Catalonia Institute for Energy Research, IREC, 08930 Sant Adrià del Besos, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Nafria
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.|Metallurgy and Materials Engineering Department, Faculty of Engineering, Bartin University , 74100 Bartin, Turkey.
authors.forename: Aziz
authors.initials: A
authors.lastname: Genç
authors.affiliation: Catalonia Institute for Energy Research, IREC, 08930 Sant Adrià del Besos, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Ibáñez
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.|Institució Catalana de Recerca i Estudis Avançats, ICREA, 08010 Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.affiliation: Departament de Química Inorgànica and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , 08028 Barcelona, Spain.
authors.forename: Pilar Ramírez
authors.initials: PR
authors.lastname: de la Piscina
authors.affiliation: Catalonia Institute for Energy Research, IREC, 08930 Sant Adrià del Besos, Spain.|Departament de Química Inorgànica and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , 08028 Barcelona, Spain.
authors.forename: Narcís
authors.initials: N
authors.lastname: Homs
authors.affiliation: Catalonia Institute for Energy Research, IREC, 08930 Sant Adrià del Besos, Spain.|Institució Catalana de Recerca i Estudis Avançats, ICREA, 08010 Barcelona, Spain.
authors.forename: Andreu
authors.initials: A
authors.lastname: Cabot