Chemistry, Department of


First Advisor

Professor Xiao Cheng Zeng

Date of this Version

Fall 11-30-2018


A DISSERTATION Presented to the Faculties of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Chemistry, Under the Supervision of Professor Xiao Cheng Zeng. Lincoln, Nebraska: December 2018

Copyright (c) 2018 Navneet Singh Khetrapal


In bulk form, gold is a well-known noble metal. However, gold nanoparticles exhibit remarkable catalytic behavior towards various types of chemical reactions. These catalytic properties are highly dependent upon the size and shape and therefore knowledge of the geometries of these nanoparticles is of prime importance. The main goal of this dissertation is, therefore, going to be towards the elucidation of the structures of novel gold clusters using a combined experimental and theoretical approach and subsequent modeling to explore the binding of simple substrates like carbon monoxide with gold clusters. The theoretical method used to study the structural evolution of these nanoparticles involves global optimization. Basin-hopping (BH) algorithm in conjugation with Density Functional Theory (DFT) has been extremely successful in exploring the potential energy surface of novel pure and mixed gold clusters. The combination of photoelectron spectroscopy with theoretical methods is an important tool for studying the various types of pure as well as alloy gold nanoclusters. Apart from the structure elucidation of medium-sized gold nanoclusters and small-sized gold-aluminum alloy clusters, this method has also enabled us to unravel new geometries of medium-sized gold nanoclusters when they bind to small molecule substrates such as carbon monoxide and therefore help in better understanding of the catalytic activities and in illustrating the reaction pathways.

Adviser: Xiao Cheng Zeng