FeS Decorated Nickel Iron Hydroxide with Regulated Coordination Environment towards Improved Methanol Oxidation Reaction

Abstract

Methanol oxidation reaction (MOR) has garnered extensive attention as a pivotal technology for the synthesis of high value-added products. However, the high selectivity of methanol oxidation products into high-value formic acid needs precise control of the reaction pathway and the reconstruction of Ni. Herein, a microbial corrosion strategy was employed to construct Ni(Fe)(OH)₂ -FeS nanosheets. The constructed Ni(Fe)(OH)₂-FeS electrode exhibits superior MOR performance, which achieves 1.378 V vs. RHE@10 mA cm^-2 with a Tafel slope of 21 mV dec^-1 . Density functional theory calculations indicate the introduced S^2- enable modulate the d-band center and coordination environment of Ni Sites. Furthermore, this effect can promote the buildup of *OH at the active site, thus increasing the local *OH concentration around the electrode surface. Moreover, the anion S^2- promotes the surface reconstruction of the Ni(Fe)(OH)₂ , and enhances the Ni-O bond in Ni(Fe)OOH-FeS, thereby optimizing adsorption and binding energy of intermediate, which significantly enhance MOR performance. This innovative design facilitates the controlled conversion of the *CHO intermediate to HCOOH by enhancing the CO-free pathway, which demonstrates significant potential in fostering the sustainable advancement of the interdisciplinary fusion between biology and clean energy technologies.