Ligand-Induced Morphological Engineering and Electronic Modulation of CoCu Bimetallic Catalysts for Efficient HMF Electrooxidation

Abstract

Developing efficient non-precious-metal catalysts for 5-hydroxymethylfurfural (HMF) electrooxidation is of great significance for sustainable and green chemical synthesis. Herein, we report a facile, one-step electrodeposition of a 2,6-naphthalenedicarboxylic acid (2,6-NDA)-coordinated CoCu bimetallic catalyst. The 2,6-NDA ligand not only enables morphological engineering, endowing the 2,6-NDA-CoCu catalyst with a dense and crack-free nanosheet surface that significantly increases the electrochemically active surface area, but also induces interfacial electronic reconstruction via its strong electron-withdrawing effect, thereby modulating the local electron density at the metal centers. This favorable coordination environment facilitates the oxidation of cobalt sites to high-valence states, which substantially enriches the high-activity species on the catalyst surface. Electrochemical evaluations demonstrate that the optimized 2,6-NDA-CoCu catalyst exhibits exceptional activity for 5-hydroxymethylfurfural oxidation (HMFOR), delivering an impressive current density of 800 mA cm⁻² at 1.46 V (vs. RHE). At 1.45 V, the catalyst achieves an HMF conversion of 98.23%, a Faradaic efficiency of 95.85%, and an FDCA yield of 96.33%. Furthermore, the system maintains robust stability over multiple cycles, with both yield and efficiency exceeding 94%. This work provides a rational paradigm for designing high-performance electrocatalysts via ligand-induced electronic engineering for advanced biomass electrolysis.