Elucidating structure-properties relations for the design of highly selective carbon-based HMF sorbents

Abstract

5-Hydroxymethyl furfural (HMF) production from fructose dehydration in DMSO with various catalytic systems has shown superior selectivity and high yields. Yet, the subsequent need for energy-intensive separation of HMF from HMF/fructose/DMSO mixtures challenges the practical feasibility of this process. Microporous carbon materials have shown promise as substrates for alternative adsorption-based separations, but the origin of HMF selectivity and adsorption capacity, and thereby structure-properties relations enabling rational design of enhanced sorbents, has remained elusive. Through systematic quantification of the functionality and texture of various commercial (BP2000, Norit1240) and synthetic carbons (three-dimensionally ordered macroporous carbons; mesoporous carbons), we link, for the first time, adsorption capacity and HMF adsorption selectivity to two tunable materials properties of the carbon sorbents: microporosity and oxygenate functionality (i.e., carbon polarity). In the process, we exploit these newly elucidated structure-properties relations for realizing a class of synthetic carbons with sub-micron particulate morphology that achieve more than 60% higher selectivity and more than 20% higher capacity for HMF over fructose as compared to the best performing commercial product, BP2000. (C) 2013 Elsevier Inc. All rights reserved.