The cover art is attributed to a paper entitled “Generation and Reaction of Benzyl Triflates by Anodic Oxidation of Toluenes” by Dr. Yosuke Ashikari et al. as an Editor’s Choice. This study presents a highly original electrochemical strategy that enables the selective generation and utilization of benzyl triflates via the anodic two-electron oxidation of toluenes. By conducting the oxidation at −78 °C in a divided H-type cell, the authors successfully accumulated benzyl triflates as stable benzyl-cation equivalents, a species directly confirmed for the first time by low-temperature NMR analysis. Subsequent reactions with alcohols, thiols, and amines proceeded smoothly to afford benzylic ethers and thioethers under mild, activator-free conditions, effectively suppressing the overoxidation issues inherent to conventional benzylic C–H functionalization.

The cover art symbolizes this concept by depicting lightning as the driving electrochemical energy, the divided cell environment, and various molecular species drifting within the “triflate pool,” illustrating the accumulation and reactivity of the anodically generated intermediates. This work offers a valuable and innovative platform for C–H bond functionalization using electrochemically generated cationic intermediates.

Direct functionalization of benzylic C–H bonds provides an attractive route to access valuable benzylic derivatives, but selective oxidation remains challenging due to overoxidation of the desired products. Herein, we report a new electrochemical strategy for the generation and utilization of benzyl triflates. In this study, benzyl triflates were successfully generated from two-electron oxidation of toluenes, and their formation was directly confirmed by NMR spectroscopy. The anodically generated triflates were subsequently converted into benzylic ethers and thioethers. This approach suppresses overoxidation by generating cationic intermediates under nucleophile-free conditions, which can then be selectively transformed.

This study investigates silicon as a promising anode material for future all-solid-state lithium-ion batteries. However, when lithium insertion and extraction are repeated near the maximum capacity, the associated volumetric expansion and contraction cause structural degradation, leading to accelerated deterioration of charge-discharge cycle performance. To fundamentally address this issue, this study analyzes the basic chemical and mechanical properties of Li–Si alloys (Li_xSi; 0 < x ∼ 5) using first-principles calculations. In particular, this study evaluates the chemical potential—which has not been thoroughly investigated before—as well as the bulk modulus, including compositions and polymorphs that had not been previously studied. The analysis shows that, the chemical potential becomes as high as +75 kJ mol⁻² when the composition ratio approaches the maximum one of 4.4 in Li–Si alloys. This is consistent with the fact that no Li–Si alloys with a composition beyond this ratio have been observed. In addition, the calculations revealed that the chemical potential takes positive values at several points before reaching the maximum composition, suggesting that lithium insertion into the silicon anode may not proceed smoothly in these cases. Regarding the bulk modulus, this study finds that it generally decreases with increasing lithium content, consistent with previous reports. However, in the case of LiSi, which has three different polymorphs, significant variation in the bulk modulus is observed. Furthermore, by calculating the volumetric expansion during lithium insertion, including compositions not previously examined, this study finds that the volume expansion is approximately proportional to the lithium composition ratio which is in agreement with earlier studies, although the slope of the increase varies slightly.

Bilirubin oxidase (BOD) is a widely used enzyme for biofuel cell cathodes. When suitably oriented, BOD can transfer electrons directly to electrodes. The BOD variant used herein orients favorably on negatively charged surfaces. In this work, the effectiveness of low-molecular-weight organic compounds in increasing the amount of BOD oriented for direct electron transfer on MgOC electrodes is examined.

The long-promised lifespan of alkaline water electrolysis is due to its stable power system. However, when used for hydrogen production with renewable energy, electrode degradation caused by an intermittent power supply must be predicted. In alkaline water electrolysis, where all cells are connected in series, intermittent shutdowns create a reverse current. This results in the reduction of anode material during the stopping time, and the repeated oxidation-reduction process due to intermittent power causes degradation. Electrodes coated with thermally decomposed electrocatalysts on a nickel substrate have demonstrated high durability in industrial alkaline electrolysis applications. However, their durability decreases when exposed to reverse currents due to the detachment of the catalyst layer. In this study, we aimed to improve durability and catalytic performance by using stepwise temperature control during the coating heat treatment and reducing the annealing duration. This two-step process formed an intermediate NiO_x-rich layer between the catalyst and substrate. This might strengthen interfacial adhesion and improve the durability of the catalyst layer. However, at high temperatures, as the heat treatment time increases, the intermediate oxide layer becomes more pronounced, subsequently increasing the NiO proportion. The low electrical conductivity of NiO leads to increased resistance and decreased initial performance. The most appropriate heat treatment conditions were 300 °C decomposition followed by 500 °C annealing with a relatively short time. The performance interval, maintained at approximately 1.7 V vs. RHE, increased by about three times compared to conventional consistent heat treatment. This improvement is believed to be due to optimal formation of the catalyst structure via thermal decomposition and of the intermediate oxide layer via annealing.

Green hydrogen production and carbon dioxide electroreduction in neutral aqueous solutions, are key reactions for zero-carbon energy systems. In both cases, the oxygen evolution reaction (OER) is a counter reaction that requires a high overpotential. Therefore, active and durable OER catalysts at neutral pH are demanded. We previously reported that brownmillerite-type Ca₂Fe_0.75Co_1.25O₅ calcined at 1073 K exhibits higher OER activity and durability than that of perovskite-type iron cobalt oxides and Ca₂Fe_2−xCo_xO₅ (x ≤ 1) at neutral pH. Here, we synthesized Ca₂Fe_0.5Co_1.5O₅ at temperatures between 1073 and 1373 K and compared its OER activity and durability at neutral pH with those of Ca₂FeCoO₅ and Ca₂Fe_0.75Co_1.25O₅. X-ray diffraction and chemical composition analysis revealed that pure brownmillerite phase of Ca₂Fe_0.5Co_1.5O₅ was only achieved at 1273 K, while samples calcined at lower and higher temperatures contained Ca₃Co₂O₆ and CaO impurities, respectively. The Ca₂Fe_0.5Co_1.5O₅ exhibited the highest activity and durability for over 100 h, significantly outperforming Ca₂Fe_0.75Co_1.25O₅ without significant changes in morphology or bulk composition.