Large-diameter hexagonal NiCo bimetallic oxides micron sheets for synergistic electro-synthesis of THFDCA

Tetrahydrofuran-2,5-dicarboxylic acid (THFDCA) is a bio-based cyclic dicarboxylic acid with greater flexibility and biosafety than the renowned 2,5-furandicarboxylic acid (FDCA), but its synthesis is limited to thermochemical methods with only several reports. This study pioneers an electrocatalytic strategy for the efficient synthesis of THFDCA via the oxidation of tetrahydrofuran dimethanol (THFDM). By constructing NiCo bimetallic oxides micron sheets on nickel foam (NiCoMS/NF) through controlled pyrolysis of a metal-organic framework (MOF)-like precursor, we achieved a remarkable THFDM conversion of 99.0 % and THFDCA yield up to 98.2 %, surpassing all reports on thermocatalytic oxidation as we know. In-depth analysis revealed that the synergistic effect between NiO and Co3O4 contributes to the high catalytic performance. In-situ Raman and rotating ring-disk electrode (RRDE) techniques were employed to discuss the reaction mechanism and the inhibitory effect on oxygen evolution reaction (OER). This study not only provides a paradigm-shifting, groundbreaking strategy for the synthesis of the flexible cyclic dicarboxylic acid derived from furanic biomass but also offers deep insights into the synergistic effects of electrocatalysts.