Ru nanoparticle decorated Ni(OH)2 nanosheets for highly efficient electrochemical synthesis of 2,5-furandicarboxylic acid: experimental and theoretical studies

Abstract

Electrocatalytic oxidation of biomass derivative 5-hydroxymethylfurfural (HMF) is a promising route to produce high value-added 2,5-furandicarboxylic acid (FDCA). The development of high-performance electrocatalysts for the HMF oxidation reaction (HMFOR) is important for electrochemical synthesis of FDCA. Herein, Ru nanoparticle (RuNP) decorated Ni(OH)₂ nanosheet arrays were synthesized on nickel foam (NF), which can serve as a self-supporting electrode for high-efficiency electrocatalysis of HMFOR. The RuNPs-Ni(OH)₂/NF can achieve a current density of 40 mA cm⁻² at a low potential of 1.35 V (vs. RHE), and a yield of FDCA close to 99.4% is obtained. Benefiting from the loading effect of Ru nanoparticles, the yield rate of FDCA for RuNPs-Ni(OH)₂/NF is as high as 36.51 mg h⁻¹ cm⁻², which is 26 times that of Ru-free Ni(OH)₂/NF. Besides the high catalytic activity and excellent selectivity, the RuNPs-Ni(OH)₂/NF also has good stability for electrochemical synthesis of FDCA. Theoretical calculations reveal that Ru decoration on Ni(OH)₂ can promote the surface reconstruction of the catalyst to generate high-valence reactive Ni species for HMFOR, reduce the adsorption energy of HMF, enhance the electronic interactions between HMF and the catalyst, and accelerate the kinetic process of HMFOR. This study not only develops a high-performance electrocatalyst for electrochemical synthesis of FDCA but also profoundly clarifies the catalytic mechanism of HMFOR.