Lattice Oxygen Leaching Induced Amorphous/Crystalline Heterostructured MnOx/Ni9S8 Nanoarrays Construction for Efficient Methanol Electro-Reforming at Large Current Density.

Electrocatalytic reforming of methanol into highvalue-added formate is regarded as a promising alternative to alkaline oxygen evolution reaction with sluggish reaction kinetics. However, it holds huge challenges for the practical application of conventional nickel-based catalysts under industrial-level current density. Herein, the amorphous/crystalline heterostructured oxygen vacancy-rich MnOx/Ni9S8 nanoarrays induced by lattice oxygen leaching are constructed for efficient methanol oxidation reaction (MOR). The MnOx/Ni9S8 exhibits an extremely low potential of 1.55 V (vs. RHE) at an industrial-grade current density of 1 A cm-2, together with a 96.76% Faradaic efficiency of formate. A membrane-free MnOx/Ni9S8 || MnOx/Ni9S8 cell for MOR || HER delivers electrocatalytic activity that requires merely a cell voltage of 1.57 V for 100 mA cm-2, yielding a 95.66% Faradaic efficiency while maintaining continuous electrolysis for 150 h. The systematic studies manifest that the coupling of amorphous/crystalline interfaces and numerous oxygen vacancies not only modulates electron distribution and accelerates the generation of active sites NiIII-OOH, but also enhances the adsorption capacity for OH- and methanol, thereby boosting overall performance. This work demonstrates an efficient lattice oxygen leaching-induced strategy for industrial-level methanol electro-reforming to formate, providing a new prototype for valorization of biomass into high-value chemicals and production of hydrogen energy.