(509cg) The Role of Oxygen-Containing Functional Groups of Carbon Surfaces

Oxygen-containing functional groups (OCFGs) on carbon surfaces impact catalytic performance in ways that are not well understood.^[1,2] For example, the hydrophilicity and acidity-basicity of carbon materials could be controlled and these can change reactivity. Notably, some of the acidic OCFGs could act as Brønsted acid sites^[3,4]. Currently, the characterization of acidic OCFGs on carbon surfaces is challenging. Furthermore, the effect of the microenvironment of carbon-based catalysts on catalytic performance remains poorly understood.

In this study, we apply probe molecules to conduct alcohol dehydration and investigate the acidic OCFGs (Brønsted acid sites) of a diverse library of materials we synthesize. Those probe molecules undergo acid-catalyzed elimination reactions and are sensitive to the acidic OCFGs on carbon surfaces. Comprehensive XPS characterization, machine learning, as well as operando XPS characterization are coupled with kinetics to identify the acidic OCFGs on carbon surfaces and correlate structure and specifically OCFGs with the observed reactivity.