Ce-doped NiOOH generated through the electrocatalytic self-reconstruction of Ce-doped Ni-MOFs for the efficient electrooxidation of 5-hydroxymethylfurfural

Abstract

In this study, nickel foam-supported Ce-doped NiOOH nanosheets were obtained via the electrocatalytic self-reconstruction of Ce-doped Ni-BDC (where BDC stands for a terephthalic acid linker) metal–organic frameworks (MOFs). The NiCe(10%)-MOF after cyclic voltammetry (CV) activation (named NiCe(10%)-MOF-CV) showed better performance in the oxygen evolution reaction (OER) and 5-hydroxymethylfurfural oxidation reaction (HMFOR) compared with Ni-MOF-CV. It also exhibited a more satisfactory current density (153.15 mA cm⁻²) compared with Ni-MOF-CV (87.7 mA cm⁻²) in the HMFOR at 1.5 V_RHE, and after 20 successive cycles, it still exhibited a satisfactory HMF conversion rate (100%), 2,5-furanodicarboxylic acid (FDCA) yield (98.6%) and faradaic efficiency (99.8%) at 1.44 V_RHE. The excellent HMFOR performance of NiCe(10%)-MOF-CV was attributed to the strong electron interaction between Ce and Ni, the enhanced adsorption of OH* and HMF, and the reduced energy barrier of the rate-determining step. Finally, the HMFOR mechanism was explored, with an aim to provide guidance for the future designs of electrocatalysts.