UC Merced

Many chemical reactions occurring at aqueous interfaces show different kinetics and thermodynamics than the same reactions occurring in the bulk. The nature of these chemical reactions is central in understanding environmental, industrial, and biological processes; but remains incompletely understood due to its complexity and experimental difficulties in tuning and characterizing reactions at aqueous interfaces. In this dissertation, different experimental approaches are utilized to generate large, well-characterized aqueous interfaces for kinetic studies of chemical reactions. Chapter 1 introduces deviations of chemistry at aqueous interfaces that can alter physiochemical properties of chemical processes. In chapter 2, I study mechanistic rate accelerations of organic reactions at the organic-water interface and find that free OH groups of interfacial water molecules play an essential role in catalysis. In chapter 3, I revisit the effects of electric fields at the air-water interface of water microdroplets on directly converting water into hydrogen peroxide which is thermodynamically unfavorable in solution. Contrast to previous reports, no hydrogen peroxide production is observed in water microdroplets when tuning the electric fields at droplet surfaces. In chapter 4, I discuss claims of spontaneous hydrogen peroxide formation at the air-water interface and pinpoint potential experiments that can help to clarify them. Chapter 5 is the conclusion of the work presented in this dissertation.