Degree

Doctor of Philosophy (PhD)

Department

Chemical Engineering

Document Type

Dissertation

Abstract

Selective activation of C–O, C–H, and C–C bonds underpins biomass upgrading, alkane functionalization, and CO₂ conversion. Despite their importance, the electronic factors governing catalytic performance remain incompletely understood, and many industrial processes still rely on empirical trends or material-specific observations. This dissertation addresses this gap by applying density functional theory (DFT), thermodynamic decomposition, and electronic-structure analysis to identify unifying principles of reactivity across transition-metal phosphides, vanadate oxides, copper-based electrocatalysts, and mixed IrO₂–RuO₂ layers. This work examines how charge transfer, orbital localization, and ligand-induced perturbations control reaction pathways in diverse catalytic systems. C–O bond scission in 2-methyltetrahydrofuran (MTHF) and methanol was studied across isostructural transition metals and their phosphide analogues, revealing that phosphorus incorporation consistently shifts selectivity toward hindered C–O activation. Thermodynamic surrogate reactions and constrained-orbital DFT (CO-DFT) show that this shift arises from weakened CH(b) π interactions and enhanced stabilization of transition states associated with tertiary C–O cleavage. C–H activation in C₁–C₃ alkanes on V₂O₅ and Mg-vanadates was analyzed using methyl-addition energies, demonstrating that Mg incorporation modifies lattice flexibility and local oxygen character to systematically tune hydrocarbon reactivity. The dissertation also investigates doped Cu electrocatalysts for CO₂ reduction. Quasi-atomic orbital charge analysis quantifies how P, Sn, and Se dopants polarize Cu active sites and promote selectivity toward C₂+ products, while reconstructed surface models reveal how these effects evolve under reaction conditions. Adsorption studies on single-layer IrO₂, RuO₂, and mixed Ir–Ru oxide films further demonstrate that ligand effects and electronic redistribution dominate viii trends in N₂ and O binding. Computational alchemy and population analyses decompose adsorption-induced charge rearrangements into contributions from metal sites and subsurface oxygen, clarifying how mixed-metal oxides tune adsorption energetics. Overall, this dissertation demonstrates that consistent application of electronic-structure tools provides a unified framework for interpreting reactivity trends across chemically distinct catalytic materials. These insights offer practical computational strategies for understanding catalytic behavior and guiding the design of improved materials for biomass conversion, hydrocarbon activation, and electrochemical CO₂ reduction.

Date

1-14-2026

Committee Chair

Plaisance, Craig

Download

Share

COinS