Size-Dependency of Electrochemically Grown Copper Nanoclusters Derived from Single Copper Atoms for the CO Reduction Reaction.

Electrochemically grown copper nanoclusters (CuNCs: < 3 nm) from single-atom catalysts have recently attracted intensive attention as electrocatalysts for CO2 and CO reduction reaction (CO2RR/CORR) because they exhibit distinct product selectivity compared with conventional Cu nanoparticles (typically larger than 10 nm). Herein, we conducted a detailed investigation into the size dependence of CuNCs on selectivity for multicarbon (C2+) production in CORR. These nanoclusters were electrochemically grown from single Cu atoms dispersed on covalent triazine frameworks (Cu-CTFs).

Finite Element Analysis of Local pH Variations in Electrolysis with Porous Electrodes, Considering Water Self-Ionization.

A finite element model was developed to simulate ion fluxes and local pH changes within and around porous electrodes during the H evolution reaction (HER) in acidic electrolytes. This model is particularly characterized by its ability to simulate scenarios in which the local pH inside and near the cathode exceeds 7, even under bulk acidic conditions (e.g.

Long Period Voltage Oscillations Associated with Reaction Changes between CO Reduction and H Formation in Zero-Gap-Type CO Electrochemical Reactor.

Zero-gap-type reactors with gas diffusion electrodes (GDE) that facilitate the CO reduction reaction (CORR) are attractive due to their high current density and low applied voltage. These reactors, however, suffer from salt precipitation and anolyte flooding of the cathode, leading to a short lifetime. Here, using a zero-gap reactor with a transparent cathode end plate, we report periodic voltage oscillations under constant current operation.

Fluorinated Amide-Based Electrolytes Induce a Sustained Low-Charging Voltage Plateau under Conditions Verifying the Feasibility of Achieving 500 Wh kg Class Li-O Batteries.

Although lithium-oxygen batteries (LOBs) hold the promise of high gravimetric energy density, this potential is hindered by high charging voltages. To ensure that the charging voltage remains low, it is crucial to generate discharge products that can be easily decomposed during the successive charging process. In this study, we discovered that the use of amide-based electrolyte solvents containing a fluorinated moiety can notably establish a sustained voltage plateau at low-charging voltages at around 3.

Quantitative Analysis and Manipulation of Alkali Metal Cations at the Cathode Surface in Membrane Electrode Assembly Electrolyzers for CO Reduction Reactions.

The stable operation of the CO reduction reaction (CORR) in membrane electrode assembly (MEA) electrolyzers is known to be hindered by the accumulation of bicarbonate salt, which are derived from alkali metal cations in anolytes, on the cathode side. In this study, we conducted a quantitative evaluation of the correlation between the CORR activity and the transported alkali metal cations in MEA electrolyzers. As a result, although the presence of transported alkali metal cations on the cathode surface significantly contributes to the generation of C compounds, the rate of K ion transport did not match the selectivity of C, suggesting that a continuous supply of high amount of K to the cathode surface is not required for C formation.

Light Wavelength as a Contributory Factor of Environmental Fitness in the Cyanobacterial Circadian Clock.

A circadian clock is an essential system that drives the 24-h expression rhythms for adaptation to day-night cycles. The molecular mechanism of the circadian clock has been extensively studied in cyanobacteria harboring the KaiC-based timing system. Nevertheless, our understanding of the physiological significance of the cyanobacterial circadian clock is still limited.

Microbial Biomanufacturing Using Chemically Synthesized Non-Natural Sugars as the Substrate.

The bioproduction of valuable materials using biomass sugars is attracting attention as an environmentally friendly technology. However, its ability to fulfil the enormous demand to produce fuels and chemical products is limited. With a view towards the future development of a novel bioproduction process that addresses these concerns, this study investigated the feasibility of bioproduction of valuable substances using Corynebacterium glutamicum (C.

Construction of an autocatalytic reaction cycle in neutral medium for synthesis of life-sustaining sugars.

Autocatalytic mechanisms in carbon metabolism, such as the Calvin cycle, are responsible for the biological assimilation of CO to form organic compounds with complex structures, including sugars. Compounds that form C-C bonds with CO are regenerated in these autocatalytic reaction cycles, and the products are concurrently released. The formose reaction in basic aqueous solution has attracted attention as a nonbiological reaction involving an autocatalytic reaction cycle that non-enzymatically synthesizes sugars from the C1 compound formaldehyde.

Recent research advances on non-linear phenomena in various biosystems.

All biological phenomena can be classified as open, dissipative and non-linear. Moreover, the most typical phenomena are associated with non-linearity, dissipation and openness in biological systems. In this review article, four research topics on non-linear biosystems are described to show the examples from various biological systems.

Statically and dynamically flexible hydrogen-bonded frameworks based on 4,5,9,10-tetrakis(4-carboxyphenyl)pyrene.

Aperture shape and size of flexible hydrogen-bonded organic frameworks (HOF) were statically modulated using various aromatic solvents, and dynamically changed by desorption and adsorption of the solvent molecules.

Edge-Site-Free and Topological-Defect-Rich Carbon Cathode for High-Performance Lithium-Oxygen Batteries.

The rational design of a stable and catalytic carbon cathode is crucial for the development of rechargeable lithium-oxygen (LiO ) batteries. An edge-site-free and topological-defect-rich graphene-based material is proposed as a pure carbon cathode that drastically improves LiO battery performance, even in the absence of extra catalysts and mediators. The proposed graphene-based material is synthesized using the advanced template technique coupled with high-temperature annealing at 1800 °C.

Selective and high-rate CO electroreduction by metal-doped covalent triazine frameworks: a computational and experimental hybrid approach.

The electrochemical CO reduction reaction (CORR) has attracted intensive attention as a technology to achieve a carbon-neutral society. The use of gas diffusion electrodes (GDEs) enables the realization of high-rate CORRs, which is one of the critical requirements for social implementation. Although both a high reaction rate and good selectivity are simultaneously required for electrocatalysts on GDEs, no systematic study of the relationship among active metal centers in electrocatalysts, reaction rate, and selectivity under high-rate CORR conditions has been reported.

A Tin Oxide-Coated Copper Foam Hybridized with a Gas Diffusion Electrode for Efficient CO Reduction to Formate with a Current Density Exceeding 1 A cm.

The electrochemical CO reduction reaction (CO RR) is a promising strategy for closing the carbon cycle. Increasing the current density (  J) for CO RR products is a critical requirement for the social implementation of this technology. Herein, nanoscale tin-oxide-modified copper-oxide foam is hybridized with a carbon-based gas-diffusion electrode (GDE).

Dissection of respiratory and cyclic electron transport in Synechocystis sp. PCC 6803.

Cyclic electron transport (CET) is an attractive hypothesis for regulating photosynthetic electron transport and producing the additional ATP in oxygenic phototrophs. The concept of CET has been established in the last decades, and it is proposed to function in the progenitor of oxygenic photosynthesis, cyanobacteria. The in vivo activity of CET is frequently evaluated either from the redox state of the reaction center chlorophyll in photosystem (PS) I, P700, in the absence of PSII activity or by comparing PSI and PSII activities through the P700 redox state and chlorophyll fluorescence, respectively.

Order-of-magnitude enhancement in photocurrent generation of Synechocystis sp. PCC 6803 by outer membrane deprivation.

Biophotovoltaics (BPV) generates electricity from reducing equivalent(s) produced by photosynthetic organisms by exploiting a phenomenon called extracellular electron transfer (EET), where reducing equivalent(s) is transferred to external electron acceptors. Although cyanobacteria have been extensively studied for BPV because of their high photosynthetic activity and ease of handling, their low EET activity poses a limitation. Here, we show an order-of-magnitude enhancement in photocurrent generation of the cyanobacterium Synechocystis sp.

Anticancer Activity of Cell-Penetrating Redox Phospholipid Polymers.

Redox-active molecules are promising anticancer compounds because cancer cells are vulnerable to oxidative stress. Anticancer drugs are often incorporated into synthetic polymers to improve water solubility, stability, and retention in the body. Most conventional redox-active polymers are regarded as stimuli-responsive polymers, which induce the release of anticancer drugs in response to the surrounding redox environment.

NADPH production in dark stages is critical for cyanobacterial photocurrent generation: a study using mutants deficient in oxidative pentose phosphate pathway.

Live cyanobacteria and algae integrated onto an extracellular electrode can generate a light-induced current (i.e., a photocurrent).

Overlooked Factors Required for Electrolyte Solvents in Li-O Batteries: Capabilities of Quenching O and Forming Highly-Decomposable Li O.

Although sufficient tolerance against attack by superoxide radicals (O ) has been mainly recognized as an important property for Li-O battery (LOB) electrolytes, recent evidence has revealed that other critical factors also govern the cyclability, prompting a reconsideration of the basic design guidelines of LOB electrolytes. Here, we found that LOBs equipped with a N,N-dimethylacetamide (DMA)-based electrolyte exhibited better cyclability compared with other standard LOB electrolytes. This superior cyclability is attributable to the capabilities of quenching O and forming highly decomposable Li O .

Positive Feedback Mechanism to Increase the Charging Voltage of Li-O Batteries.

The large overpotential of nonaqueous Li-O batteries when charging causes low round-trip efficiency and decomposition of the electrode materials and electrolyte. The origins of this overpotential have been enthusiastically explored to date; however, a full understanding has not yet been reached because of the complexity of multistep reaction mechanisms. Here, we applied structural and electrochemical analysis techniques to investigate the reaction step that results in the increase of the overpotential when charging.

Coral symbionts evolved a functional polycistronic flavodiiron gene.

Photosynthesis in cyanobacteria, green algae, and basal land plants is protected against excess reducing pressure on the photosynthetic chain by flavodiiron proteins (FLV) that dissipate photosynthetic electrons by reducing O. In these organisms, the genes encoding FLV are always conserved in the form of a pair of two-type isozymes (FLVA and FLVB) that are believed to function in O photo-reduction as a heterodimer. While coral symbionts (dinoflagellates of the family Symbiodiniaceae) are the only algae to harbor FLV in photosynthetic red plastid lineage, only one gene is found in transcriptomes and its role and activity remain unknown.

Isotopic Depth Profiling of Discharge Products Identifies Reactive Interfaces in an Aprotic Li-O Battery with a Redox Mediator.

Prior to the practical application of rechargeable aprotic Li-O batteries, the high charging overpotentials of these devices (which inevitably cause irreversible parasitic reactions) must be addressed. The use of redox mediators (RMs) that oxidatively decompose the discharge product, LiO, is one promising solution to this problem. However, the mitigating effect of RMs is currently insufficient, and so it would be beneficial to clarify the LiO reductive growth and oxidative decomposition mechanisms.

Quantification of NAD(P)H in cyanobacterial cells by a phenol extraction method.

In photosynthetic organisms, it is recognized that the intracellular redox ratio of NADPH is regulated within an appropriate range for the cooperative function of a wide variety of physiological processes. However, despite its importance, there is large variability in the values of the NADPH fraction [NADPH/(NADPH + NADP)] quantitatively estimated to date. In the present study, the light response of the NADPH fraction was investigated by applying a novel NADP(H) extraction method using phenol / chloroform / isoamyl alcohol (PCI) in the cyanobacterium Synechocystis sp.

Effect of Cobalt Speciation and the Graphitization of the Carbon Matrix on the CO Electroreduction Activity of Co/N-Doped Carbon Materials.

The electroreduction of carbon dioxide is considered a key reaction for the valorization of CO emitted in industrial processes or even present in the environment. Cobalt-nitrogen co-doped carbon materials featuring atomically dispersed Co-N sites have been shown to display superior activities and selectivities for the reduction of carbon dioxide to CO, which, in combination with H (i.e.