Methanol Electroreforming Coupled to Green Hydrogen Production over Bifunctional NiIr-Based Metal-Organic Framework Nanosheet Arrays

Abstract The conventional water electrolysis system is seriously restricted by the sluggish kinetics of anodic oxygen evolution reaction. Electroreforming of organic substances coupling with electrochemical hydrogen evolution is an innovative strategy to achieve energy-saving co-generation of value-added chemicals and hydrogen. Herein, NiIr-based metal‐organic framework (MOF) nanosheet arrays are in situ grown on Ni foam (NiIr-MOF/NF) and employed as a bifunctional self-supported electrocatalyst to oxidize small organic molecules of methanol to the value-added chemical formate while efficiently facilitating hydrogen production. The constructed co-electrolytic system based on HER-methanol oxidation reaction (MOR) bifunctional NiIr-MOF/NF electrocatalyst possesses ultra-high energy conversion efficiency for electrochemically assisted overall water splitting, with a low cell voltage of only 1.39 V to achieve the current density of 10 mA cm−2. Especially, the Faradaic efficiencies of the cathode and anode could both reached nearly 100% for H2 and formate generated in 1 M KOH containing 4 M methanol.