Aluminum Cluster Anion Reactivity: Applications in Energetic Materials and Catalysts

Open Access
Author:
Woodward, William Henry Hunter
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
July 15, 2011
Committee Members:
  • Castleman, Dissertation Advisor
  • Albert Welford Castleman Jr., Committee Chair
  • Nicholas Winograd, Committee Member
  • John B Asbury, Committee Member
  • Richard A Yetter, Committee Member
Keywords:
  • cluster deposition
  • aluminum
  • clusters
  • cluster reactivity
Abstract:
The research presented in this dissertation focuses on the size-selective properties of aluminum clusters and their applications in catalysis and energetic materials. As the size of metals approaches the molecular regime, their properties begin to differ from the bulk. In fact, individual clusters exhibit different properties as even a single atom is added or removed. Some of these clusters display characteristics similar to elements of the periodic table, giving rise to a “3-D periodic table.” Additionally, some clusters demonstrate characteristics that are unique from any element, which is desirable for use in a variety of applications including catalysis and energetic materials. It is the goal of this research to study these clusters in detail in order to one day construct a material which maintains these desirable properties. Specifically, the resistance of specific aluminum clusters to reaction with oxygen is explored, and it is discussed how this could lead to the use of aluminum cluster-based solids in combustible materials. Additionally, recent research has led to the discovery of a unique form of aluminum cluster reactivity wherein polar bonds are catalytically broken. It is discussed how this mechanism could be used to generate hydrogen from water/alcohol or cleave high-energy carbonyl bonds. The possibility of a “cluster-assembled material” would imply that material properties could be selectively tailored to fit the needs of the application, which would give rise to a whole new field of solid-state physical chemistry.