UC Berkeley

The American Chemical Society defines Green Chemistry in terms of a visionary set of principles that encourage rethinking of the material and chemical economy to reduce waste, decrease hazard, and innovate towards a sustainable future. While Green Chemistry, like all chemistry, is ultimately an empirical science, computational efforts lend significant support to implementation of greener frameworks. The present work is divided into two parts, each describing work in first-principles quantum chemistry to address pressing problems in Green Chemistry. The first concerns the development of predictive models for catalysis applications, specifically the carbon dioxide reduction reaction (CO2RR). In this, we utilize high-level electronic structure theory to analyze the nature of the metal--carbon monoxide (M-CO) chemistry, the fundamental interaction in the electrocatalytic CO2RR. In this, we provide detailed description of the physical and chemical contributions toward M-CO bonding, significantly deepening understands of these bonds. We also characterize errors associated with the use of pseudopotentials for modeling relevant chemical systems, finding that these represent an often overlooked but significant inhibitor to accurate systems modeling. The second part of this work examines the mechanism of action for p-phenylenediamine (PPD) antidegradants, which are ubiquitous in tire manufacturing globally. While these compounds protect rubber against degradation due to surface ozone (O3), one of their key transformation products is acutely toxic to aquatic life. Through application of modern density functional theory, we determine a detailed mechanism for the ozonation of these compounds, which was hitherto absent from the literature. This mechanism also provides key insights into the particularly high O3 reactivity of PPDs, and could help guide future efforts to identify non-toxic alternatives for tire manufacturing.