Numerous active sites in self-supporting Co₃O₄ nanobelt array for boosted and stabilized 5-hydroxymethylfurfural electro-oxidation

Constructing an efficient electrocatalyst for the oxidation of 5-Hydroxymethylfurfural (HMF) to 2,5-furan dicarboxylic acid (FDCA) is highly desirable in achieving biomass conversion. Generally, there are two strategies to enhance the electrocatalyst's activity: increasing the number of active site or increasing the intrinsic activity of each active site. Compared with the latter, the former is usually ignored in the HMF oxidation reaction (HMFOR), but it is very critical for practical applications. Herein, we fabricate a self-supporting three-dimensional porous Co3O4 nanobelt array decorated on nickel foam (P-Co3O4 -NBA@NF) electrode with numerous active sites. Benefiting from the unique structural feature, P-Co3O4 -NBA@NF electrode demonstrates nearly 100% of HMF conversion efficiency, 96.9% of FDCA selectivity, and 97.0% of Faraday efficiency. Notably, it can also deliver remarkable long-term stability over 30 continuous cycles. These exceptional features position P-Co3O4 -NBA@NF as one of the promising electrocatalysts reported thus far for HMFOR.