Inter-American Materials Collaboration (CIAM): Structural and Electronic characteristics of nanoclusters with catalytic properties

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Abstract Proposal Title: Inter-American Materials Collaboration (CIAM): Structural and Electronic Characteristics of Nanoclusters with Catalytic Applications Proposal Number: CTS-0502951 Principal Investigator: Enrique Iglesia Institution: University of California-Berkeley Analysis (rationale for decision): This project addresses the preparation, characterization, and surface reactivity of clusters of nanometer size containing one or two types of metal atoms. These materials are useful because of their ability to bind molecules and to increase the rate of their chemical transformations. The research will address how the rate and selectivity of C-H bond activation is influenced by the size and the composition of these clusters. The activation of C-H bonds in small molecules is a critical step in the formation of H2 suitable as an energy carrier in fuel cells, of carbon nanotubes useful in microelectronic devices and electrodes, and of H2-CO mixtures suitable for the production of fuels and chemicals. In these processes, methane, ubiquitous in natural gas and containing one of strongest C-H bonds in nature, reacts on surfaces with O2, CO2, or H2O molecules to form these products. This collaboration will bring together essential skills and expertise in complementary aspects of the physics and chemistry of small clusters with important details of surface reactivity not yet fully understood. These combined efforts aim to bring unprecedented details to the knowledge of structure-function relations for nanometer-sized metal clusters with chemically reactive surfaces. More specifically, the studies will explore the nature of small metal clusters at the conditions in which they function as catalysts, which often perturb their structure and surface composition from those prevalent at much lower temperatures in unreactive environments and which can also lead to surface mobility and to nearly amorphous exposed surfaces. These properties of small catalytic clusters at reactive conditions will permit assessment of the fidelity of cluster models currently used in molecular simulations of surface reactions and to provide more faithful representations of such clusters if so required. This research effort crosses disciplinary boundaries between the physics and chemistry communities to probe some of most relevant issues in the production of fuels, the use of energy, and the sustainable manufacturing of essential chemicals. The approach and methods developed and used will impact broadly on-going progress in the atomic-level characterization of surfaces in small structures and will assess the need to include fast dynamics of surfaces in small clusters within theoretical descriptions of their electronic properties and chemical reactivity. The collaboration proposed builds intellectual bridges among complementary groups in Argentina, U.S., and Brazil in areas that are critical to the scientific and economic growth of two emerging economies with significant human and natural resources and potential.