Trends in single transition metal atom/oxide support interactions from density functional theory

Open Access
Author:
O'Connor, Nolan J
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Michael Janik, Thesis Supervisor
  • Michael Janik, Honors Advisor
  • Robert Rioux, Faculty Reader
Keywords:
  • DFT
  • Metal Oxide
  • Single atom catalyst
  • catalysis
Abstract:
Density Functional Theory (DFT) is used to identify predictions of metal atom binding on oxide surfaces. These supported single metal atoms offer intriguing properties as heterogeneous catalysts. Typically supported on oxide surfaces, single-atom catalysts (SACs) offer enhanced reactivity and selectivity while maximizing dispersion of the expensive active metal component. However, single metal atoms are susceptible to sintering, a process by which the atoms agglomerate into larger, more thermodynamically stable nanoparticles. The loss of active sites from such agglomeration compromises the SAC’s high reactivity. Stronger interfacial binding between the atom and oxide support reduces the rate of sintering and thereby results in smaller, more dispersed nanoparticles. Herein, we employ DFT to demonstrate that strong interfacial binding is correlated with inherent properties of the metal and support: namely, the metal’s oxide formation energy and the support’s reducibility. DFT is used to further elucidate the electronic structure effects that govern metal-support binding strength. Finally, we report an empirical screening tool for determining thermodynamically stable combinations of metals and oxide supports.