Efficient electrolysis of 5-hydroxymethylfurfural to the biopolymer-precursor furandicarboxylic acid in a zero-gap MEA-type electrolyzer

Replacement of today's established chemical production processes by "green" sustainable alternatives has become a scientific priority. The oxidative conversion of 5-hydroxymethylfurfural (5-HMF) to the biopolymer component 2.5-furandicarboxylic acid paired with green electrolytic hydrogen production is a promising emerging green process. Here, we present a family of active selective and stable interlayer anion-tuned NiX (X = Fe, Mn, Co, V) bimetallic-layered, double-hydroxide catalysts for the selective oxidation of 5-HMF to 2.5-furandicarboxylic acid in a zero-gap MEA-type electrolyzer. We report that tuning the structural interlayer distance of the catalyst by anion exchange gives rise to previously unachieved catalytic performance for the anodic production of the biopolymer building block. Operando differential electrochemical mass spectrometry analysis reveals the electrode window for the perfectly selective HMF conversion. The role of the catalyst dopants, their real surface areas, the stability of the catalytic interface, and aspects of its favorable techno-economics are discussed.