Accessing Strain Engineered V‐Fe(O)OH from Prussian Blue Analogue Precatalyst for Efficient Anodic Oxidation Reactions

Abstract

AbstractPrussian blue analogues (PBAs) are promising precatalysts to access active metal oxyhydroxide [M(O)OH] phases for anodic oxidation reactions (AORs). In this study, we have introduced a d‐d electron complementation strategy to fine‐tune the electronic features of a VOFe‐PBA precatalyst. Spectroscopic studies revealed the altered coordination and electronic features of the VOFe‐PBA precatalyst compared to the FeFe‐PBA counterpart. The electrochemical activation of the VOFe‐PBA precatalyst led to the formation of a strained V‐Fe(O)OH active catalyst. Notably, V‐Fe(O)OH demonstrated exceptional performance, requiring a potential of only 1.56 V versus RHE for oxygen evolution reaction (OER) and 1.42 V versus RHE for iodide oxidation reaction (IOR) at a current density of 100 mA cm−2, significantly outperforming the Fe(O)OH. When employed in IOR‐assisted water splitting, V‐Fe(O)OH achieved an energy efficiency of 60% compared to overall water splitting. In‐situ Raman studies reflected the potential dependent generation of active reaction intermediates, which participated in IOR to produce iodate. Mechanistic investigations suggested the involvement of a lattice oxygen mechanism (LOM) facilitated by a proton‐decoupled electron transfer (PDET) pathway.