Titanium Oxide‐Confined Manganese Oxide for One‐Step Electrocatalytic Preparation of 2,5‐Furandicarboxylic Acid in Acidic Media

Abstract

The electrochemical conversion of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA) is an attractive strategy for producing sustainable substitutes for petroleum‐derived polymers. Developing acidic electrocatalysis system is of great significance for the separation of FDCA and improves the efficiency of the whole electrolyzer, which is limited by the availability of effective catalysts. Here, we report a TiOx@MnOx electrocatalyst, which can obtain FDCA precipitation in one‐step in acidic media. The TiOx@MnOx catalyst with the active MnOx species confined in the acid‐resistant TiOx nanowires, and obtained a consistent yield of FDCA precipitation in the continuous conversion of 100 mM HMF (∼24 % under the stoichiometric charge). Electrochemical impedance analyses and electrolysis experiments revealed that the catalytic performance of TiOx@MnOx is related to the concentration of HMF. Further research found that the electrolyzer, electrolysis potential, reaction temperature, and HMF concentration affect the yield and FE of FDCA. This work demonstrates TiOx@MnOx is a practical and inexpensive catalyst for the sustainable synthesis of FDCA in an acidic electrocatalysis system.

Electro‐ and Photocatalytic Oxidative Upgrading of Bio‐based 5‐Hydroxymethylfurfural

“…To improve the efficiency of FDCA large‐scale production, further efforts should be made to enhance the catalytic activity and durability of MnO x ‐based catalysts. TiO x @MnO x catalyst was prepared by confinement of MnO x in TiO x nanowire framework, which showed excellent stability and electrocatalytic activity in an acidic medium [92] . The integration of electrocatalytic HMF‐to‐FDCA oxidation with hydrogen production under acidic conditions is a very promising strategy, which also provides an interesting reference for research in the relevant fields.…”

Alloy‐Driven Efficient Electrocatalytic Oxidation of Biomass‐Derived 5‐Hydroxymethylfurfural towards 2,5‐Furandicarboxylic Acid: A Review

“…Unfortunately, although this pattern was different from the conventional chemically catalyzed HMF oxidation process, this study did not probe in depth the mechanism of the effect of substrate concentration on the reaction activity. Considering that the large‐scale production of FDCA required a significant amount of HMF, Gao et al [84] . also investigated the effect of substrate concentration on the electrocatalytic oxidation of HMF.…”

“…Nevertheless, MA is an ideal biomass-derived platform molecule, which provides a new pathway for the electrochemical value-added conversion of HMF under acidic media. Inspired by this study, Gao et al [84] prepared a TiO x nanowire framework-constrained MnO x electrocatalyst by rational design of the electrocatalyst geometry to improve the catalytic activity and durability of MnO x -based catalysts, achieving the one-step preparation and separation of the target product FDCA by large-scale electrochemical oxidation of HMF in acidic media. However, there are still few studies to achieve efficient HMF electrocatalytic oxidation to generate FDCA under an acidic environment up to now.…”

“…Unfortunately, although this pattern was different from the conventional chemically catalyzed HMF oxidation process, this study did not probe in depth the mechanism of the effect of substrate concentration on the reaction activity. Considering that the large-scale production of FDCA required a significant amount of HMF, Gao et al [84] also investigated the effect of substrate concentration on the electrocatalytic oxidation of HMF. 20, 50, and 100 mm HMF were selected for electrocatalytic oxidation, and the results were shown in Figure 15a, where the FDCA yield increased first and then decreased slightly when the substrate concentration was gradually increased.…”

One‐Pot Synthesis of 2,5‐Furandicarboxylic Acid from 2‐Furoic Acid by a Pd‐catalyzed Bromination–Hydroxycarbonylation Tandem Reaction in Acetate Buffer

“…In the literature, there are three main routes for the synthesis of 2,5‐FDCA as summarized in Scheme 1 . Route‐I involves oxidation of 5‐(hydroxymethyl) furfural (HMF) to 2,5‐FDCA through a number of thermal‐catalytic,[ 4 , 5 , 6 , 7 , 8 , 9 , 10 ] electrocatalytic, [11] photocatalytic [12] and biocatalytic[ 13 , 14 , 15 ] processes. Thereinto, sequential oxidation of the two functional groups (formyl and hydroxyl) bound to the furan ring leads to the formation of 2,5‐FDCA.…”