Synthesis and Characerization of Catalysts and Electrocatalysts Using Combinatorial Methods

Open Access
Author:
Ramanathan, Ramnarayanan
Graduate Program:
Materials
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
July 27, 2005
Committee Members:
  • Thomas E Mallouk, Committee Chair
  • Chunshan Song, Committee Member
  • Digby D Macdonald, Committee Member
  • Darrell Velegol, Committee Member
Keywords:
  • split pool
  • electrocatalysis
  • combinatorial chemistry
  • catalysis
  • physical intuition
  • directed sorting
Abstract:
Thesis Advisor: Thomas E. Mallouk This thesis documents attempts at solving three problems. Bead-based parallel synthetic and screening methods based on matrix algorithms were developed. The method was applied to search for new heterogeneous catalysts for dehydrogenation of methylcyclohexane. The most powerful use of the method to date was to optimize metal adsorption and evaluate catalysts as a function of incident energy, likely to be important in the future, should availability of energy be an optimization parameter. This work also highlighted the importance of order of addition of metal salts on catalytic activity and a portion of this work resulted in a patent with UOP LLC, Desplaines, Illinois. Combinatorial methods were also investigated as a tool to search for carbon-monoxide tolerant anode electrocatalysts and methanol tolerant cathode electrocatalysts, resulting in discovery of no new electrocatalysts. A physically intuitive scaling criterion was developed to analyze all experiments on electrocatalysts, providing insight for future experiments. We attempted to solve the CO poisoning problem in polymer electrolyte fuel cells using carbon molecular sieves as a separator. This approach was unsuccessful in solving the CO poisoning problem, possibly due to the tendency of the carbon molecular sieves to concentrate CO and CO2 in pore walls.