Electrocatalysis, which can store electrical energy from renewable sources like solar and wind in chemical bonds, is an attractive solution to activating abundant small molecule precursors. In particular, the oxygen reduction reaction (ORR) plays important roles in both biological energy conversion and next-generation energy technologies. Stemming from continuous efforts to mimic biological active sites for O<sub>2</sub> storage, transport, and activation, porphyrinic complexes with iron, cobalt, and manganese active sites have been studied extensively as molecular catalysts for the ORR. Inspired to explore alternatives, we have developed rigid bipyridine- and terpyridine-based ligand frameworks, as well as flexible tripodal ligand frameworks, which support Mn, Fe, and Co metal centers during the ORR. Although the ligand frameworks differ in terms of conjugation, they all show sensitivity to non-covalent hydrogen-bonding interactions and proton transfer reactions in the inner-coordination sphere, which can be modulated by the use of redox mediators and secondary-sphere modifications to the ligand framework. The resulting performance for the ORR can be tuned both in terms of activity and selectivity for water or hydrogen peroxide.

Earth abundant non-porphyrinic molecular transition metal catalysts for dioxygen reduction

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.