NiV Layered Double Hydroxide for Efficient and Scalable Electrochemical Oxidation of 5-Hydroxymethylfurfural to High-Purity 2,5-Furandicarboxylic Acid

Electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a promising pathway for chemical synthesis, yet challenges remain in catalyst efficiency, product purity, and scalable implementation. In this study, NiV layered double hydroxide (LDH) was explored as a highly effective catalyst for electrochemical HMF oxidation. The incorporation of V significantly stabilized the Ni³⁺ state, promoted strong HMF adsorption, and accelerated the oxidation of key intermediates, notably improving the catalytic performance. Consequently, NiV LDH achieved high FDCA yields (>95%) even at a low potential of 1.35 V vs RHE. Electrochemical analyses, including steady-state linear sweep voltammetry and current deconvolution studies, revealed that NiV LDH uniquely facilitated rapid aldehyde oxidation, particularly for the rate-determining intermediate 5-formyl-2-furancarboxylic acid (FFCA). Furthermore, a single-pass electrolyzer configuration was developed to effectively mitigate base-induced degradation and maintain high FDCA purity. Using a 100 cm² electrolyzer, this system continuously produced FDCA at a production rate of 62 g day^–1 over 40 h, delivering purity levels comparable to those of commercial FDCA. These findings present an efficient, scalable approach for high-purity FDCA synthesis, substantially advancing the practical implementation of electrochemical biomass valorization.