The world’s shift to the production of energy from sustainable sources requires the development of large energy storage. One of the best methods to store surplus energy produced from environmentally friendly methods is as elemental hydrogen, using electrolysis in alkaline electrolyzers. Currently, this technology is hampered by the sluggish oxygen evolution reaction (OER), which limits its overall efficiency and durability. One of the most popular directions is to develop cheap, durable, and active platinum-group-metal-free (PGM-free) catalysts. In this category, the benchmark catalyst is NiFeOOH. Here, synthetic, electrochemical, spectroscopic, and theoretical methods were used to design, synthesize, and investigate novel PGM-free catalysts with enhanced durability and activity. Using an easy and cheap one-step synthetic precipitation method, titanium atoms in various amounts were introduced in the NiFeOOH structure, forming Ni x Fe y Ti z OOH. One of these compounds (Ni:Fe:Ti = 85.75:7.70:6.55) shows a very low overpotential on GC (400 mV, at a current density of 10 mA/cm2) and high current density (27.9 mA cm–2) at a potential of 1.8 V vs RHE. This is a higher activity toward the OER in comparison to the benchmark catalyst; in addition, the compound has higher stability at prolonged exposure to high potentials.

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Trimetallic double hydroxide NiFeCo−OH is prepared by coprecipitation, from which three different catalysts are fabricated by different heat treatments, all at 350 °C maximum temperature. Among the prepared catalysts, the one prepared at a heating and cooling rate of 2 °C min−1 in N2 atmosphere (designated NiFeCo−N2‐2 °C) displays the best catalytic properties after stability testing, exhibiting a high current density (9.06 mA cm−2 at 320 mV), low Tafel slope (72.9 mV dec−1), good stability (over 20 h), high turnover frequency (0.304 s−1), and high mass activity (46.52 A g−1 at 320 mV). Stability tests reveal that the hydroxide phase is less suitable for long‐term use than catalysts with an oxide phase. Two causes are identified for the loss of stability in the hydroxide phase: a) Modeling of the distribution function of relaxation times (DFRT) reveals the increase in resistance contributed by various relaxation processes; b) density functional theory (DFT) surface energy calculations reveal that the higher surface energy of the hydroxide‐phase catalyst impairs the stability. These findings represent a new strategy to optimize catalysts for water splitting.

Herein, the mass‐transfer mechanism of flash sintering during the transient stage is examined using an in‐house‐made flash and quench (FQ) system. Visual findings of samples during and after FQ experiments and high‐resolution electron microscopy are given. Many new observations regarding the flash‐sintering nature are presented and discussed. Samples that underwent FQ experiments either show no sign of sintering or local sintering and grain growth due to a hotspot. These findings aid in untying of the two phenomena. Electron microscopy imaging of flash and quenched samples shows atypical microstructures. Such microstructural anomalies include sintering, massive grain growth, and visual findings on the surface. These findings establish flash sintering as a set of phenomena, caused by an abrupt and local increase in temperature (a “flash event”), where only one of which is sintering.

Flash sintering is under research to allow fast, cost‐effective and energy efficient sintering of ceramics. In article, number http://doi.wiley.com/10.1002/adem.202001499, by Yoed Tsur and co‐workers, an in‐house‐made system is constructed for quenching flash sintered samples at mid‐experiment. The system is helpful in further revealing the nature of the phenomenon. The results untie the link between flash and sintering. (Cover design: Nofar Laor)