Our group focuses on understanding reactions on metal oxide surfaces in complex media, from gaseous to liquid environments. Our current interest is measuring fundamental surface reactions on iron interfaces. Iron oxide is an earth-abundant metal oxide that plays a large role in heterogeneous catalytic processes and environmental reactions in soils, atmospheric particulate reactions and corrosion mechanisms. We aim to connect fundamental surface chemical reactions that are prevalent in heterogeneous catalysis to understanding complex surface reactions in environmental science.
1. Surface Chemistry of Oxidation and Corrosion
In this project we aim to understand the mechanisms of the initial stages of surface corrosion and redox reactions that drive surface environmental chemistry, electrochemical and catalysis processes. Reactions on iron are measured at the gas/solid and liquid/solid interface using vacuum and ambient spectroscopy and microscopy. We connect surface chemistry at multiple interfaces in solution with morphology changes at the air/liquid/solid interface. We use PM-IRRAS at the air/liquid/solid interface, AFM, and XPS to investigate these redox reactions.
2. Iron Surface Chemistry and Catalysis
Chemical Transformations and Reactions on Iron Oxide Surfaces and Interfaces. We measure fundamental reactions on earth-abundant materials, from surface chemical reactions and the restructuring of the surface at the gas/solid interface.
3. Designing Tailored Metal Oxide Nano and Mesostructures on Functionalized Surfaces for Next-generation Heterogeneous Catalysts and Semiconductors. (previous project)
We use surface functionalization as active area sites for metal and metal oxide structures using area selective deposition (ASD). Oxidation of the surface of 2D materials lead to various functional groups that act as reactive sites with atomic layer deposition (ALD) metal-organic precursors to grow metal oxide materials with unique surface morphologies. This project uses a bottom-up approach for selective growth of nano- and mesoscale materials for tailored growth of heterogeneous catalysts.
1) Bridging the materials gap: How do reactions change with size and crystal structure? We design and grow metal oxide nano and meso-sized structures and compare surface reactions with pristine single crystal surfaces to address these issues.
2) Bridging the pressure and phase gap: How do we connect reactions under controlled conditions (ultra-high vacuum) with ambient pressure conditions and reactions in the condensed phase, in complex environments? The variables that change in these scenarios are oxygen pressure, relative humidity, and chemical concentration. We have the capability to measure reactions at the gas/solid and liquid/solid interface to cross boundaries and measure reactions at interfaces.
3) Bridging the chemical gap: We aim to connect what is known of catalytic reactions and apply this knowledge to measuring and understanding complex environmental processes. By measuring fundamental surface reactions, we apply learned knowledge of simplistic single crystal surfaces to complex systems.
Our plan encompasses designing model systems using bottom-up surface chemical approaches by surface functionalization of well-defined surfaces and growing tailored metal oxide structures using molecular level controlled deposition processes. These new materials that vary in size and crystal structure will then be used as model systems to compare to reaction on well-defined crystalline surfaces to study chemical reactions at the gas/solid and liquid/solid interface.
Our strategy will connect fundamental surface chemical reactions on model and complex metal oxide materials that will uncover critical reactions addressing energy and environmental challenges.