The desire to fabricate materials with well defined, controllable properties and structures, on the nanometre scale, coupled with the flexibility afforded by intermetallic materials, has generated interest in bimetallic alloy clusters or "nanoalloys" [1,2]. One of the major reasons for interest in nanoalloy particles is the fact that their chemical and physical properties may be tuned by varying the composition and atomic ordering, as well as the size of the clusters. Their surface structures, compositions and segregation properties are of interest as they are important in determining chemical reactivity, and especially catalytic activity.

I will start by introducing the field of nanoalloys and reasons for studying them. I will then describe the model (the Gupta many-body potential) and the methodologies (Genetic Algorithms and systematic optimization studies of geometric shell clusters) that we have used to study the structures and segregation properties of nanoalloys to study a variety of nanoalloy systems, such as Pd-Pt, Pd-Au and Cu-Ag. The results of recent DFT calculations on these nanoalloys will also be presented, along with results of chemisorption studies of small molecules on pure metal clusters and nanoalloys and the effect of a MgO substrate on the geometry and chemical ordering of AuPd nanoalloys.

[1] "Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles" R. Ferrando, J. Jellinek and R. L. Johnston, Chem. Rev. 2008, 108, 845-910. [2] Faraday Discussion 138: "Nanoalloys - From Theory to Application" Faraday Disc. 2008, 138.

Short biography: Professor Roy L. Johnston

Roy Johnston is Professor of Computational Chemistry and Deputy Head of School. He is the School's Director of Research, Chair of the Postgraduate Research Committee of the College of Engineering and Physical Sciences and represents the College on the University's Graduate School Management Board. He is also a member of the Research Computing Management Board. Career:

2006 Professor of Computational Chemistry, University of Birmingham
2003 Reader in Computational Chemistry, University of Birmingham
2002 Senior Lecturer in Chemistry, University of Birmingham
1995 Lecturer in Inorganic Chemistry, University of Birmingham.
1989-95 Royal Society University Research Fellow, University of Sussex.
1988-89 NATO Postdoctoral Fellow, University of Arizona (U.S.A.) in the group of Professor Dennis L. Lichtenberger.
1987-88 NATO Postdoctoral Fellow, Cornell University (U.S.A.) in the group of Professor Roald Hoffmann.
1983-86 DPhil, University of Oxford (under supervision of Dr. D. Michael P. Mingos), Thesis: "Theoretical Studies of Polyhedral Molecules".
1979-83 BA Hons. (I) in Chemistry, St. Catherine's College, University of Oxford.

Roy's research spans the fields of computational nanoscience and nature-inspired computation. Examples include the study of elemental and bimetallic clusters, the application of genetic and other nature-inspired algorithms to optimisation problems in chemistry and physics (e.g. protein folding, self-assembly, nanoparticle structure optimisation and structure solution from powder X-ray diffraction data), and developing techniques for visualising and analysing the complexity of energy landscapes. He is a Fellow of the Royal Society of Chemistry and is a past secretary of the RSC Theoretical Chemistry Group.