The anodic electrooxidation of ethanol to value-added acetate is an excellent example of replacing the oxygen evolution reaction to promote the cathodic hydrogen evolution reaction and save energy. Herein, we present a colloidal strategy to produce Ni-Fe bimetallic alloy nanoparticles (NPs) as efficient electrocatalysts for the electrooxidation of ethanol in alkaline media. Ni-Fe alloy NPs deliver a current density of 100 mA·cm⁻² in a 1.0 M KOH solution containing 1.0 M ethanol merely at 1.5 V vs. reversible hydrogen electrode (RHE), well above the performance of other electrocatalysts in a similar system. Within continuous 10 h testing at this external potential, this electrode is able to produce an average of 0.49 mmol·cm⁻²·h⁻¹ of acetate with an ethanol-to-acetate Faradaic efficiency of 80%. A series of spectroscopy techniques are used to probe the electrocatalytic process and analyze the electrolyte. Additionally, density functional theory (DFT) calculations demonstrate that the iron in the alloy NPs significantly enhances the electroconductivity and electron transfer, shifts the rate-limiting step, and lowers the energy barrier during the ethanol-to-acetate reaction pathway.

Rational design and synthesis of non-precious-metal catalyst plays an important role in improving the activity and stability for oxygen reduction reaction (ORR) but remains a major challenge. In this work, we used a facile approach to synthesize iron nanoparticles encapsulated in nitrogen-doped porous carbon materials (Fe@N-C) from functionalized metal-organic frameworks (MOFs, MET-6). Embedding Fe nanoparticles into the carbon skeleton increases the graphitization degree and the proportion of graphitic N as well as promotes the formation of mesopores in the catalyst. The Fe@N-C-30 catalyst showed the excellent ORR activity in alkaline solutions (E₀ = 0.97 V vs. RHE, E_1/2 = 0.89 V vs. RHE). Moreover, the Fe@N-C-30 catalyst exhibited better methanol resistance and long-term stability when compared to commercial Pt/C. The superior ORR performance could be attributed to the combination of high electrochemical surface area, relative high portion of graphitic-N, unique porous structures and the synergistic effect between the encapsulated Fe particles and the N-doped carbon layer. This work provides a promising method to construct efficient non-precious-metal ORR catalyst through MOFs.