Highly Ordered Conductive Metal‐Organic Frameworks with Chemically Confined Polyoxometalate Clusters: A Dual‐Functional Electrocatalyst for Efficient H ₂ O ₂ Synthesis and Biomass Valorization

Abstract

Abstract The design of bifunctional and high‐performance electrocatalysts that can be used as both cathodes and anodes for the two‐electron oxygen reduction reaction (2e − ORR) and biomass valorization is attracting increasing attention. Herein, a conserved ligand replacement strategy is developed for the synthesis of highly ordered conductive metal‐organic frameworks (Ni‐HITP, HITP = 2, 3, 6, 7, 10, 11‐hexaiminotriphenylene) with chemically confined phosphotungstic acid (PW 12 ) nanoclusters in the nanopores. The newly formed Ni−O−W bonds in the resultant Ni‐HITP/PW 12 electrocatalysts modulate the electronic structures of both Ni and W sites, which are favorable for cathodic 2e − ORR to H 2 O 2 production and anodic 5‐hydroxymethylfurfural oxidation reaction (HMFOR) to 2, 5‐furandicarboxylic acid (FDCA), respectively. In combination with the deliberately retained conductive frameworks and ordered pores, the dual‐functional Ni‐HITP/PW 12 composites enable a H 2 O 2 production rate of 9.51 mol g cat −1  h −1 and an FDCA yield of 96.8% at a current density of 100 mA cm −2 /cell voltage of 1.38 V in an integrated 2e − ORR/HMFOR system, significantly improved than the traditional 2e − ORR/oxygen evolution reaction system. This work has provided new insights into the rational design of advanced electrocatalysts and electrocatalytic systems for the green synthesis of valuable chemicals.