Evaluating the impact of anodic oxidation reactions on water splitting using Prussian blue analog-derived metal-(oxy)hydroxides

Abstract

Prussian blue analog (PBA)-derived Fe–Co(O)OH showed improved anodic oxidation of a series of organic and inorganic compounds without the interference from the oxygen evolution reaction.

Metal–organic frameworks (MOFs) for hybrid water electrolysis: structure–property–performance correlation

“…In a recent study from our group, we explored a series of AORs with a MOF-based Fe-Co(O)OH active catalyst. 156 The XPS and XAS study showed that the active Fe-Co(O)OH catalyst had dominant Co 3+ and Fe 3+ species, which played a crucial role in giving excellent performance for AORs. Moreover, excellent conversion and selectivity were observed for all the AORs with industrial-level current density.…”

“…Consequently, the creation of this highly stable active catalyst enhances the stability of MOFs for anodic oxidation reactions. 40,156 The following steps are involved in the electrocatalytic oxidation of organic and inorganic substrates: 72,79,131,132 the substrates' adsorption onto the active catalyst surface is the first step, followed by hydroxyl addition, electron transfer (oxidation), and deprotonation (proton decoupling). For the most part, anodic oxidation follows these common processes.…”

“…Different oxidation products from the same substrate are also produced depending on the quantity of electrons transported. 38,156 Fig. 11 Based on the literature reports, metal-oxyhydroxide M(O)OH is the real active catalyst for different anodic oxidation reactions.…”

“…38 Following AOR, powder X-ray diffraction (PXRD) studies may reveal peaks in the 2y range of 11-151, corresponding to the M(O)OH interlayer spacing. 156 In some cases, following AOR, the surface-active catalyst is primarily amorphous. Infrared spectroscopy (IR) after AOR shows peaks corresponding to -OH and M-O species, indicating the formation of M(O)OH.…”

“…Moreover, MOFs face several hurdles when used for AORs, including achieving high faradaic efficiency and scalability for industrial applications. 156 Most MOFs do not provide high faradaic efficiency at large current densities. Table 1 clearly expresses that most MOFs do not reach industrial-level current density in a two-electrode system.…”