title: Large stability and high catalytic activities of sub-nm metal (0) clusters: implications into the nucleation and growth theory.
abstract: Clusters are stable catalytic species, which are produced during the synthesis of nanoparticles (NPs). Their existence contradicts the thermodynamic principles used to explain the formation of NPs by the classical nucleation and growth theories (NGTs). Using chemical and electrochemical methods we will show that depending on the experimental conditions one can produce either Ag clusters or Ag NPs. Moreover, using already prepared Ag clusters one can observe the disappearance of the usual induction period observed for the kinetics of NP formation, indicating that clusters catalyze the formation of NPs. Taking these data together with some previous examples of cluster-catalyzed anisotropic growth, we derived a qualitative approach to include the catalytic activities of clusters into the formation of NPs, which is incorporated into the NGT. Some qualitative conclusions about the main experimental parameters, which affect the formation of clusters versus NPs, as well as the catalytic mechanism versus the non-catalytic one, are also described.
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Piñeiro
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain; Technische Universität Berlin, Institut für Chemie, 10623 Berlin, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Buceta
authors.affiliation: NANOGAP, Milladoiro (Ames), E-15895 A Coruña, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Calvo
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Shahana
authors.initials: S
authors.lastname: Huseyinova
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Cuerva
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Pérez
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: Domínguez
authors.affiliation: Physical Chemistry Department, Faculty of Chemistry, and NANOMAG Laboratory, Research Technological Institute, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain. Electronic address: malopez.quintela@usc.es.
authors.forename: M Arturo
authors.initials: MA
authors.lastname: López-Quintela
keywords: Cluster catalysis; Cluster synthesis; Nanoparticle synthesis; Nucleation and growth mechanisms