Tug of War between Epoxidation and Ketonization in Electrochemical Alkene Oxidation: Pulling the Rope for Ketonization

Author: Jiang, Chenyu

Year: 2026

Degree: Dissertation (Ph.D.)

Advisor: Manthiram, Karthish

Committee Members: See, Kimberly; Stoltz, Brian M.; Goddard, William A., III; Manthiram, Karthish

Option: Chemistry

Abstract

The electrochemical oxidation of organic molecules utilizing renewable electricity has emerged as a sustainable alternative to energy-intensive thermal processes in the chemical industry. This thesis investigates electrochemical oxygen-atom transfer reactions to transform alkenes into value-added products using water as the oxygen source under ambient conditions, with a focus on understanding and controlling the competing pathways between epoxidation and ketonization. Using MnOx as a model electrocatalyst in acetonitrile/water blended electrolytes, a substrate-scope study and complementary kinetic and operando spectroscopic investigations revealed that ketone/epoxide selectivity is influenced by an interplay of alkene electronics, catalyst oxidation states, and the reaction conditions. In particular, ketonization was demonstrated to be selective at lower water content, coinciding with a less oxidized catalyst. Such insights were employed in screening and optimization of Pd-based bimetallic electrocatalysts for the selective ketonization of 1-butene to 2-butanone in aqueous electrolytes, a transformation with industrial relevance that remains underexplored electrochemically. Among the compositions evaluated, bimetallic Pd–Cu catalysts were found to be active for this transformation. Structural and spectroscopic characterization demonstrated that alloying Pd with Cu generates a metallic alloy phase that is preserved under oxidative electrochemical conditions, which is proposed to be responsible for the superior ketonization activity and selectivity. This work establishes key factors governing ketone/epoxide selectivity in alkene electro-oxidation and illustrates the significance of metallic catalyst character in achieving selective ketonization, expanding the product scope and providing a foundation for the rational catalyst design for alkene electro-oxidation.