Date of Award

5-31-2018

Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry/Physical/Analytical Chemistry

First Advisor

Jason R. Green

Second Advisor

Bala Sundaram

Third Advisor

Michelle Foster

Abstract

There is increasing evidence that emissions from burning fossil fuels drive climate change, necessitating a global transition to cleaner sources of energy, like hydrogen. However, many fundamental problems remain unsolved regarding the complex chemistry of combustion, with potential implications for the overall efficient utilization and safe storage of this fuel. For example, while hydrogen is an energy-dense, clean, and renewable energy carrier, it also has a propensity to auto-ignite and has a wide flammability range. These are ultimately macroscopic consequences of the microscopic reaction events. More efforts are needed to create robust theoretical frameworks that translate between these levels of description. The main focus of this dissertation will be novel theoretical methods that give a new perspective on explosion limits – the pressure/temperature boundaries that divide explosive and nonexplosive chemistry. From several kinetic mechanisms that model the non-equilibrium pathways of hydrogen oxidation, the explosion limits can be determined by the coexistence of two competing reactive phases in an ensemble of simulated trajectories. This novel perspective of chemical explosions is independent of the fuel and could have wider applicability beyond hydrogen. In addition to discussing new theoretical frameworks for explosion limits, this document also includes research conducted with cutting-edge reactive molecular dynamics. The ability to simulate the atomistic dynamics of reactive processes could be an indispensable tool, but as of now, more benchmarking is required. This dissertation highlights some of the steps taken towards validation of a reactive molecular dynamics force field and showcase the results of hydrogen combustion simulations with this atomistic model.

Comments

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