Modulation of surface properties of metal organic framework-derived carbon substrates through vacancy defects for high-value biomass conversion.

Enhancing the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2, 5-furandicarboxylic acid (FDCA) by modulating the surface properties of metal-organic framework-derived (MOF-derived) carbon substrates is an efficient approach. In this work, we successfully fabricated high-performance catalysts for the electrocatalytic oxidation reaction of HMF (HMFOR) to FDCA by introducing sulfur vacancies on NiFe alloy nanoparticle loaded MOF-derived carbon materials. The experimental results show that the use of MOF-derived carbon to support NiFe alloys can inherit the microporous and mesoporous structures of MOF precursors, provide a larger specific surface area, and can effectively limit the agglomeration of NiFe nanoparticles during pyrolysis, providing more active sites. Furthermore, the introduction of sulfur vacancies can lower the reconstruction energy barrier of the NiFe alloy, thereby facilitating the reconstruction of Ni into NiOOH with catalytic activity. The catalytic performance of the prepared catalysts exhibit excellent HMF conversions (100 %), FDCA yield (96.2 %) and Faraday Efficiency (96 %). Density functional theory (DFT) calculations indicate that 5-Hydroxymethyl-2- furancarboxylic acid (HMFCA) is the preferred pathway for the reaction and that the potential limiting step in the overall reaction is the oxidation of 5-formyl-2-furancarboxylic acid (FFCA) to FDCA. This work is expected to provide a unique perspective for improving the catalytic activity of non-precious metal nickel-based catalysts and high value conversion of biomass products.