Reaction Mechanism and Kinetics of the Liquid-Phase Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

Abstract

2,5-Furandicarboxylic acid (FDCA), which is currently prepared by catalyzing the oxidation of 5-hydroxymethylfurfural (HMF), is a biobased platform compound with broad market prospects. Herein, a detailed free-radical chain reaction mechanism consisting of both main and side reaction pathways was proposed to describe the liquid-phase air oxidation process of 5hydroxymethylfurfural to 2,5-furandicarboxylic acid over a Co/ Mn/Br catalyst. The higher reactivity of the hydroxymethyl group than the aldehyde group for HMF oxidation was first explained according to the retardation effect of alcohols on free-radical reactions and the reactive activity of active hydrogen on the two substituents of HMF. Considering the low stability of HMF, the possible side reactions including condensation, decarboxylation, decarbonylation, and ring-opening for HMF oxidation were further investigated. Subsequently, to obtain more reliable model parameters, a lumped kinetic scheme was developed considering only the formation of important and detectable reactants, intermediates, and products. Since the total reaction rate is not sensitive to the reactant concentration, a fractional kinetic model was adopted to correlate the experimental results and evaluate the kinetic parameters.

Kinetic Modeling of Homogenous Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

“…22 Specifically, Avantium has successfully utilized the MC process to produce FDCA at its pilot demonstration factory in Geleen, The Netherlands. 23 and economically viable to oxidize HMF to FDCA using MC, which is essential for an industrial application. The resonance energy of the furan ring (17 kcal/mol) is less than that of the benzene ring (36 kcal/mol), 24 so HMF is more likely to undergo ring-opening and combustion side reactions to generate maleic acid (MA), fumaric acid (FA), and CO x compared to PX.…”

Advances and future trends in selective oxidation catalysis: a critical review

“…Various alternative routes for the production of adipic acid are also discussed with merits and demerits in the literature. 112,108,113–143 Table 1 gives an idea about the various types of catalyst used and its activity for the cyclohexane oxidation.…”

“…221 Scheme 2 Catalytic mechanism scheme for the free-radical oxidation of 5-HMF to FDCA over Co/Mn/Br catalyst. 118 Catalysis Science & Technology Mini review catalyst was found selective for the oxidation of hydrocarbons using TNHP and O 2 /sacrificial aldehyde as oxidants. 115 In 2007, Lignier et al reported free-radical chain mechanism of gold-catalyzed hydrocarbon oxidation in liquid phase.…”

“…116 Later in 2015, catalytic free radical mechanism was studied for Au-Pd/MgO catalyst in the oxidation of cyclohexane. 117 Recently, Chen et al 118 presented the classical free-radical mechanism for the oxidation of 5-hydroxymethylfurfural (HMF) to furan dicarboxylic acid (FDCA) over Co/Mn/Br catalyst where the sequential process involved oxidation of alcohols to aldehydes and aldehydes to acids (Scheme 2).…”

Conversion of Glucose to 5-Hydroxymethylfurfural in Deep Eutectic Solvent of Choline Chloride–Chromium Chloride

“…Among biobased chemicals, 5-hydroxymethylfurfural (HMF) has gained the most attention because it is in the top “10 + 4” list . Moreover, HMF-derived chemicals such as 2,5-dimethylfuran, 2,5-furan dicarboxylic acid, and levulinic acid are widely used in different fields. In previous studies, using fructose as a feedstock could provide the most promising HMF yield, , but high fructose price makes this route uneconomical.…”