Electronegativity-Mediated Modulation of Cobalt Sites to Promote CoOOH Formation for 5-hydroxymethylfurfural Electrocatalytic Oxidation

Abstract

Cobalt-based catalysts have been reported to electrocatalyze the oxidation of 5-hydroxymethylfurfural (HMFOR) to high-value-added chemicals. However, generating highly active Co3+OOH at low potential remains a grand challenge. In this paper, we describe the electronegative metal-doped cobalt metal-organic frameworks (Co-MOFs) that facilitate the formation of Co3+OOH for efficient HMFOR. Electrochemical measurements and in situ characterization reveal that the introduction of electronegative metals and the use of MOF facilitate cobalt oxidation and enhance hydroxyl adsorption, thereby promoting C–OH bond activation and yielding more free water, contributing to the HMFOR performance. The obtained CoNi-BDC delivers a low potential of 1.14 V vs RHE at 10 mA cm–2 and a high current density of 560 mA cm–2 at 1.48 V vs RHE, with a Faradaic efficiency (FE) of 95% for 2,5-furandicarboxylic acid (FDCA), and favorable cycling stability. The work provides insight into promoting Co3+OOH formation for advancing the electrocatalytic conversion of biomass.