Biomass Valorization via Paired Electrosynthesis Over Vanadium Nitride‐Based Electrocatalysts

TLDR

Paired electrosynthesis can generate value‑added products at both electrodes in a cost‑effective manner. The study aims to develop paired electrosynthesis technologies for biomass utilization and energy conversion. The authors fabricated 3D vanadium nitride and Pd/VN hollow nanospheres that enable simultaneous electrocatalytic oxidation and hydrogenation of HMF, with theoretical analysis attributing VN’s superior ECO activity to a lower d‑band center that promotes HMF chemisorption. VN achieved ≥98 % HMF conversion, ≥96 % FDCA selectivity, and ≥84 % faradaic efficiency, while Pd/VN reached ≥90 % HMF conversion, ≥88 % DHMTHF selectivity, and ≥86 % faradaic efficiency, and their integration into a membrane electrode assembly indicates promise for large‑scale biomass conversion.

Abstract

Abstract Paired electrosynthesis is a promising technology with the potential to generate value‐added products at both electrodes in a cost‐effective manner. Herein, 3D vanadium nitride (VN) and Pd/VN hollow nanospheres are successfully fabricated and coupled to carry out simultaneous electrocatalytic oxidation (ECO) and electrocatalytic hydrogenation (ECH) of 5‐hydroxymethylfurfural (HMF) into 2, 5‐furandicarboxylic acid (FDCA) and 2,5‐bishydroxymethyl‐tetrahydrofuran (DHMTHF), respectively. VN shows excellent ECO performance with high HMF conversion (≥98%), FDCA selectivity (≥96%), and faradaic efficiency (≥84%) after a stability test, and Pd/VN achieves high ECH selectivity for DHMTHF at ≥88% and an HMF conversion of ≥90%, with a faradaic efficiency of ≥86%. VN and Pd/VN incorporated into a membrane electrode assembly in a paired electrolysis system shows potential for large‐scale biomass conversion and upgrading. Theoretical calculations reveal that the higher performance of VN for the production of ECO can be attributed to its lower d‐band center level relative to the Fermi level compared to that of V 2 O 5 , which favors HMF chemisorption and activation. This study paves the way for developing paired electrosynthesis technologies with the potential for biomass utilization and energy conversion.