Year: 2026
Type: preprint
Abstract: Iron-metalated nitrogen-doped carbon (Fe-N-C) materials rival platinum-based electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells, and O2 reduction is proposed to occur at atomically dispersed Fe atoms coordinated by nitrogen within the graphitic material (FeNx). In recent years, similar catalysts have been shown to be effective for aerobic oxidation of organic substrates, often under non-aqueous conditions that are very different from electrocatalytic ORR conditions. Such reactions have been the focus of limited mechanistic attention, and little is known about the active sites and/or catalyst features that contribute to improved activity. Here, we investigate Fe-NC-catalyzed aerobic oxidation of hydroquinone to benzoquinone and two other organic reactions. The FeNx site density is found to have little influence over catalytic activity. Instead, we find that the basicity of nitrogen atoms in the Fe-N-C surface is the dominant feature that correlates with catalytic activity, with diagnostic insights gained from binding isotherm measurements with pivalic acid. Fe-N-C catalytic activity is shown to correlate directly with the pivalic acid binding constant (Kads) across a series of different catalysts. These insights provide a valuable foundation for future development and optimization of improved aerobic oxidation catalysts.
Source: ChemRxiv
Institution: University of Wisconsin–Madison
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7214754494