Phase Equilibrium Regulation in ZIF-67-Derived Electrocatalysts: Degradation Mechanism and Stability Enhancement for Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) like ZIF-67 are promising electrocatalysts due to their tunable structures and porosity, but their instability in aqueous electrolytes requires a deeper understanding. This study investigates the structural evolution and degradation mechanism of ZIF-67 during the oxygen evolution reaction (OER) in alkaline media. Using atomic-resolution identical-location transmission electron microscopy, we reveal its transformation pathway: ZIF-67 first converts to Co(OH), then progressively evolves into catalytically active CoOOH and inactive CoO species, ultimately establishing a dynamic three-phase equilibrium under operational conditions.

Solidophobic Surface for Electrochemical Extraction of High-Valued Mg(OH) Coupled with H Production from Seawater.

A significant challenge in direct seawater electrolysis is the rapid deactivation of the cathode due to the large scaling of Mg(OH). Herein, we synthesized a Pt-coated highly disordered NiCu alloy (Pt-NiCu alloy) electrode with superior solidophobic behavior, enabling stable hydrogen generation (100 mA cm, >1000 h durability) and simultaneous production of Mg(OH) (>99.0% purity) in electrolyte enriched with Mg and Ca.

Progress in Anode Stability Improvement for Seawater Electrolysis to Produce Hydrogen.

Seawater electrolysis for hydrogen production is a sustainable and economical approach that can mitigate the energy crisis and global warming issues. Although various catalysts/electrodes with excellent activities have been developed for high-efficiency seawater electrolysis, their unsatisfactory durability, especially for anodes, severely impedes their industrial applications. In this review, attention is paid to the factors that affect the stability of anodes and the corresponding strategies for designing catalytic materials to prolong the anode's lifetime.

Ag Nanoparticle-Induced Surface Chloride Immobilization Strategy Enables Stable Seawater Electrolysis.

Although hydrogen gas (H ) storage might enable offshore renewable energy to be stored at scale, the commercialization of technology for H generation by seawater electrolysis depends upon the development of methods that avoid the severe corrosion of anodes by chloride (Cl ) ions. Here, it is revealed that the stability of an anode used for seawater splitting can be increased by more than an order of magnitude by loading Ag nanoparticles on the catalyst surface. In experiments, an optimized NiFe-layered double hydroxide (LDH)@Ag electrode displays stable operation at 400 mA cm in alkaline saline electrolyte and seawater for over 5000 and 2500 h, respectively.

Concerning the stability of seawater electrolysis: a corrosion mechanism study of halide on Ni-based anode.

The corrosive anions (e.g., Cl) have been recognized as the origins to cause severe corrosion of anode during seawater electrolysis, while in experiments it is found that natural seawater (~0.

Tafel Analysis Guided Optimization of Zn-O-C Catalysts for the Selective 2-Electron Oxygen Reduction Reaction in Neutral Media.

The lack of characterizations of the adsorption capability toward intermediates during reactions causes difficulties in determining the structural optimization principle of the catalysts for the 2-electron oxygen reduction reaction (2e ORR). Here, a Tafel-θ method is proposed to evaluate the surface coverage (θ) of important intermediates (*OOH and *OH) on the material surface and further help optimize the catalyst. With the assistance of Tafel-θ analysis, a Zn nanoparticle incorporated oxygen-doped carbon (Zn-O-C) catalyst with high 2e ORR performance (onset of ∼0.

The Critical Role of Additive Sulfate for Stable Alkaline Seawater Oxidation on Nickel-Based Electrodes.

Seawater electrolysis to produce hydrogen is a critical technology in marine energy projects; however, the severe anode corrosion caused by the highly concentrated chloride is a key issue should be addressed. In this work, we discover that the addition of sulfate in electrolyte can effectively retard the corrosion of chloride ions to the anode. We take nickel foam as the example and observe that the addition of sulfate can greatly improve the corrosion resistance, resulting in prolonged operating stability.