Stable Reaction Research Articles

Porous tungsten carbo-nitride supported Pt nanoparticles with high conductivity for efficient and stable hydrogen evolution reaction

Designing low-cost catalysts that offer both high mass activity and high cycling stability is crucial. Herein, a binder-free 3D self-supporting electrode composed of carbo-nitride tungsten supporting Pt nanoparticles (Pt@3DP-WNxC1-x/W) has been successfully synthesized for hydrogen evolution reaction in acid electrolyte. The tungsten carbo-nitride synthesized via a one-step heat treatment exhibits enhanced conductivity as a result of the carbonization process and optimizes the adsorption and desorption properties of WC towards H atoms through the incorporation of N atoms, thereby achieving an effective balance. Simultaneously, the N–Pt bond enhances electron transfer efficiency. This electrode exhibits outstanding electrochemical performance with a 219 mV overpotential at a current density of −300 mA cm−2. Its current density and mass activity is up to 75 mA cm−2 and 7.5 A·mgPt−1 at an overpotential of 100 mV, respectively, which are both 2.6 times higher than those of the 40% Pt/C electrode. In addition, it reveals a low Tafel slope of 38.3 mV dec−1 indicating rapid kinetics. Furthermore, the electrocatalyst shows only 3 mV day at −100 mA cm−2 after 10,000 cycles. Both theoretical calculation and experimental results show the promotion of catalytic efficiency of Pt@3DP-WNxC1-x/W brought by carbo-nitrition. This study offers a novel, efficient, and stable electrode design strategy.

In situ anchoring of Ni12P5 on ZnIn2S4 for efficient and stable photocatalytic H2 evolution

It is a great challenge to develop efficient, stable and inexpensive hydrogen evolution reaction (HER) catalysts for photocatalytic water-splitting. In this paper, Ni12P5 (NP) was in situ anchored on the surface of ZnIn2S4 (ZIS) via a solvothermal route with nickel chloride and red phosphorus as ingredients. Using triethanolamine as sacrificial agent, the photocatalytic hydrogen evolution activity of NP/ZIS was studied under visible light irradiation. At the same time, the composition, structure, morphology and photoelectrochemical properties of the as-obtained samples were analyzed through a sequence of characterization techniques. ZIS loaded with 6 wt% NP (6NP/ZIS) exhibits the best hydrogen evolution activity and excellent stability. The H2 evolution rate of 6NP/ZIS is 5.4 times higher than that of pristine ZIS and well beyond that of the physical mixture (6NP + ZIS) or even that of the optimal Pt/ZIS under the same conditions. The maximal apparent quantum yield (AQY) of 22.7 % at 400 nm is achieved, superior to the most reported performance of ZnIn2S4-based photocatalysts for HER. The anchor of NP can not only enhance the visible light absorption intensity, but also reduce the HER overpotential. More importantly, the intimate interface between ZIS and NP can promote the separation and migration of photo-excited carriers, thereby enhancing the activity of photocatalytic hydrogen evolution. The possible photocatalytic reaction mechanism was discussed.

Electrochemical Hydrogenation of Aliphatic Aldehydes and Acids using Pentlandite Catalysts

AbstractElectrochemical hydrogenations are considered a sustainable alternative to classical thermocatalytic processes prevalent in industrial conversions. Using a base metal sulfide of the pentlandite class, the hydrogenation of glutaraldehyde and propionic acid was investigated. While propionic acid could not be converted, glutaraldehyde was conveniently transformed to the semi‐ and fully hydrogenated products 5‐hydroxypentanal and 1,5‐pentanediol with a partial current density of up to 34 mA cm−2 and a Faraday efficiency of 34 %. Crucial factors for a stable and efficient reaction were found to be the use of an appropriate buffer, avoidance of low pH and the used membrane type. The reaction was implemented into a zero‐gap cell reaching a single pass conversion of up to 22 %, underlining the potential for future application.

Achieving optimal Ti content via interfacial reaction layer characteristics of diamond/Cu–Sn–Ti composites

Diamond/Cu–Sn–Ti composites as potential super-hard abrasive products were prepared in this work by spark plasma sintering at 1223 K. The effects of Ti content on the wettability, interfacial reaction layer thickness, and wear resistance of the bulk composite changes were systematically studied. The results revealed that when the Ti content was below 5 wt%, completely uncoated and partially coated diamond grains were still observed, indicating insufficient wettability, and the interfacial reaction layer appeared to be thin. When the Ti content was 5 wt%, all diamond grains were completely coated, and a continuous and stable interfacial reaction layer composed of TiC has been generated, in which the thickness reached a peak value of 1.72 μm. However, when the Ti content exceeded 5 wt%, the formation of brittle Cu41Sn11 phases was observed, which led to inferior wear resistance. The minimum weight loss was obtained at 5 wt% Ti content. Meanwhile, through FIB-TEM, confirmed that the interfacial reaction layer was mainly composed of continuous TiC layer adjacent to diamond and discontinuous TiC layer in the filler metal, and constitute the formation of a high strength metallurgical interfacial bonding layer.

Review of Methods for Converting Biomass into Biofuels

Thermochemical processes are among the most effective methods of obtaining hydrogen-rich gases from biomass. These technologies mainly include pyrolysis, gasification and hydrothermal liquefaction. Thermochemical conversion of dry biomass is similar to the conversion of fossil fuels using gasification and pyrolysis methods. Products obtained through thermochemical processes (CO and CH4) can be processed into other biofuels, e.g. syngas, a raw material for producing synthetic hydrocarbons, methanol and alcohols. In recent years, advanced research has been carried out using biomass to produce liquid fuels. The biomass pyrolysis process in the presence of a catalyst is based on the rapid heating of the biomass to a temperature of approximately 500°C in the so-called inert atmosphere in which there are no reactive gases. This process produces a liquid product: pyrolysis oil, gas and charcoal. The bio-oil produced in this process constitutes 60-75% of the mass of the biofuel and is thermally unstable because it contains up to 300 different chemical compounds. However, the bio-oil obtained in this way is incompatible with conventional liquid transport fuels (gasoline, diesel) due to its high oxygen content. Pyrolysis in the presence of a zeolite catalyst is a process that allows for the effective conversion of biomass in economic and ecological terms. A zeolite catalyst makes it possible to remove oxidized compounds in situ and modify the properties of the biofuel to ensure its compatibility with conventional transport fuels. The catalyst plays a crucial role in this process because it removes oxygen from oxygenates and, consequently, creates stable reaction products that can then be treated to obtain renewable transport fuels or other useful chemicals. The article presents methods of biomass conversion via pyrolisis, microorganisms usage, zeolite-based catalysis, biocatalysis and photo-fermentation, which poses a big possibility of diversification of renewable energy sources.

Li concentration change around Cu/LiPON interface measured by TOF-ERDA

Lithium metal is a promising anode material for the development of advanced all-solid-state batteries (ASSBs) with high energy density. Among the various solid electrolytes, lithium phosphorus oxynitride glass electrolyte (LiPON) is notable for facilitating stable Li plating-stripping reactions in ASSBs employing Li metal. The aim of this study is to examine the Li/LiPON interface, with a specific emphasis on the reductive decomposition of LiPON near this interface. We employed time-of-flight elastic recoil detection analysis (TOF-ERDA) to assess changes in Li concentration around the Cu/LiPON interface immediately prior to the Li plating reaction. Our electrochemical measurements indicate that critical decomposition of LiPON occurs when the voltage at the Cu electrode is reduced to 0.1 V vs. Li/Li+ at 25 °C, resulting in the in situ formation of Li3P operating at 0.7 V vs. Li/Li+ as an anode material. The TOF-ERDA findings reveal that this decomposition reaction results in a layer with partial decomposition (ranging from 5 to 25% on average) extending up to approximately 30 nm from the Cu/LiPON interface. This insight is vital for enhancing the design and performance of ASSBs.Graphical abstract

The gender dimension of social mood in modern Russia: the experience of historical and sociological analysis

Social mood is the most developed phenomenon of sociological theory and practice, the consideration of which is important for assessment and expertise in times of crises and obvious social changes. Social mood is considered as a phenomenon and an integral characteristic of the perception of life in society, the state of the human spiritual world, an integral form of life perception, the dominant of a really functioning social consciousness and behavior. To identify the gender characteristics of social positions, a primary analysis of the data of the All-Russian sociological monitoring "How are you, Russia?" (1992-2022) during the crisis and turning points of three decades of the modern history of Russia was carried out– 1993, 2001, 2008, 2014, 2022, The data of the research institute "Precariat: a new phenomenon in the socio-economic structure of society" are involved (RNF No.18-18-00024). The empirical basis for the secondary analysis was the data of the All-Russian centers for sociological research, statistical information, and publications in the media in current periods. A comparison of respondents' responses to problems, their prioritization in the opinions of women and men allowed us to identify dominant events, emerging new combinations of crisis phenomena of economic, political, and spiritual orders in the development of Russian society at mega-, meso-, and microlevels. The conclusion is made about the presence of common constants in the social positions of 1993, 2001, 2008, 2014, 2022, the stable reaction of society with the designation of the main problems of high cost of living, crime, social stratification. The situation of gender communities in the periods under review is characterized by an insufficient "safety cushion", alienation from a power resource, differences in assessments of social expectations about a woman's happiness from the point of view of men and women themselves, and the presence of gender-sensitive problems for both women and men.

Coupling Curvature and Hydrophobicity: A Counterintuitive Strategy for Efficient Electroreduction of Nitrate into Ammonia.

The electrochemical upcycling of nitrate (NO3-) to ammonia (NH3) holds promise for synergizing both wastewater treatment and NH3 synthesis. Efficient stripping of gaseous products (NH3, H2, and N2) from electrocatalysts is crucial for continuous and stable electrochemical reactions. This study evaluated a layered electrocatalyst structure using copper (Cu) dendrites to enable a high curvature and hydrophobicity and achieve a stratified liquid contact at the gas-liquid interface of the electrocatalyst layer. As such, gaseous product desorption or displacement from electrocatalysts was enhanced due to the separation of a wetted reaction zone and a nonwetted zone for gas transfer. Consequently, this electrocatalyst structure yielded a 2.9-fold boost in per-active-site activity compared with that with a low curvature and high hydrophilic counterpart. Moreover, a NH3 Faradaic efficiency of 90.9 ± 2.3% was achieved with nearly 100% NO3- conversion. This high-curvature hydrophobic Cu dendrite was further integrated with a gas-extraction membrane, which demonstrated a comparable NH3 yield from the real reverse osmosis retentate brine.

Cultural orientation of the “mimicry” society. The search for national self-identification in contemporary screen art

The purpose of this article is to study the peculiarities of the behavioral manifestation of Ukrainian screen characters in order to identify qualitative features characteristic of the Ukrainian mentality. This will allow us to determine the themes of screen works that will be relevant for the contemporary Ukrainian viewer, which will improve the qualitative and quantitative characteristics of Ukrainian audiovisual art.
 The methodology. Five scientific sources were studied (one dissertation, one collective scientific work, and three scientific articles), which allowed us to analyze the relationship between the behavioral reactions of the screen character and the nature of fear that was formed in the process of adaptive transformation of society. On the example of the films “The Guide” by Oles Sanin, “The Red” by Zaza Buadze, and “The Rising Hawk” by Leonid Osyka, the main themes and conflicts that characterize Ukrainian identity were identified and formulated.
 The results of the study demonstrate certain stable psychophysical reactions displayed by the screen character in a situation of existential conflict caused by the historical development of Ukrainian society. The nature of fears, as the main instrument of the motivating impulse in the process of forming cognitive, emotional and behavioral reactions, is determined by the level of the scale of the hero’s own identity recognition.
 The scientific novelty of the study lies in the author’s attempt to consider the conflict of the Ukrainian screen hero as a value clash between the goal-setting of a free individual and a society that has undergone adaptive transformations, which is realized through the manifestation of a certain behavioral nature of screen characters.
 The practical significance of the research findings will help in the process of creating new screen works. This will increase the attention to Ukrainian cinema.

Unraveling the crucial contribution of additive chromate to efficient and stable alkaline seawater oxidation on Ni-based layered double hydroxides

Seawater electrolysis to generate hydrogen offers a clean, green, and sustainable solution for new energy. However, the catalytic activity and durability of anodic catalysts are plagued by the corrosion and competitive oxidation reactions of chloride in high concentrations. In this study, we find that the additive CrO42− anions in the electrolyte can not only promote the formation and stabilization of the metal oxyhydroxide active phase but also greatly mitigate the adverse effect of Cl− on the anode. Linear sweep voltammetry, accelerated corrosion experiments, corrosion polarization curves, and charge transfer resistance results indicate that the addition of CrO42− distinctly improves oxygen evolution reaction (OER) kinetics and corrosion resistance in alkaline seawater electrolytes. Especially, the introduction of CrO42− even in the highly concentrated NaCl (2.5 M) electrolyte prolongs the durability of NiFe-LDH to almost five times the case without CrO42−. Density functional theory calculations also reveal that the adsorption of CrO42− can tune the electronic configuration of active sites of metal oxyhydroxides, enhance conductivity, and optimize the intermediate adsorption energies. This anionic additive strategy can give a better enlightenment for the development of efficient and stable oxygen evolution reactions for seawater electrolysis.

A self-assembled carbon nanotube/silicon composite battery anode stabilized with chemically reduced graphene oxide sheets

This study presents a streamlined fabrication process for lithium-ion battery (LIB) electrodes, involving the dispersion of carbon nanotubes (CNT), silicon (Si), and graphene oxide (GO) in an aqueous solution, followed by vacuum filtration to produce self-standing composite electrodes. Two reduction routes are employed to form reduced graphene oxide (rGO). The chemically reduced CNT/Si/rGO-5 %-Chem anode exhibits superior mechanical resilience compared to thermally reduced counterparts, which suffer from reduced strength and structural integrity. Chemical reduction also enhances electrochemical performance, increasing the initial capacity of the non-reduced CNT/Si/GO-5 % composite anode from 1,461 to 2,342 mAh g−1, with improved long-term cycling performance. Electrochemical impedance spectroscopy shows lower pre-cycle charge transfer resistance (148 Ω) and superior solid electrolyte interphase (SEI) resistance (43 Ω) for chemically reduced anodes compared to thermally reduced ones. After cycling, the chemically reduced composite anode exhibits reduced electrolyte resistance and charge transfer resistance, indicating stable electrochemical reactions. The composite structure undergoes adaptive rearrangements during cycling, optimizing active material utilization. In summary, CNTs accommodate silicon swelling, while chemically reduced rGO promotes stable SEI formation, highlighting the benefits of chemical reduction in enhancing mechanical durability and electrochemical performance, making the self-standing CNT/Si/rGO composite film a promising LIB anode.

Denitrification enhanced by composite carbon sources in AAO-biofilter: Efficiency and metagenomics research

Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor. An economical solid carbon source was developed by composition of polyvinyl alcohol, sodium alginate, and corncob, which was utilized as external carbon source in the anaerobic anoxic oxic (AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage, and the nitrogen removal was remarkably improved from 63.2% to 96.5%. Furthermore, the effluent chemical oxygen demand maintained at 35 mg/L or even lower, and the total nitrogen was reduced to less than 2 mg/L. Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides, respectively. The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO3−-N to NO2−-N conversion in both AAO and the biofilter reactors, thus enabled stable reaction. The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abundance of genes related to the tricarboxylic acid cycle, and then guaranteed efficient carbon metabolism. The results indicate that the composite carbon source is feasible for denitrification enhancement of AAO-biofilter, which contribute to the theoretical foundation for practical nitrogen removal application.

Cu/Ni(OH)2 nanocomposites for efficient and stable electrocatalysis nitrate reduction reaction to ammonia

Herein, the low-cost Cu/Ni(OH)2 nanocomposites are fabricated and act as an electrode for nitrate reduction reaction (NO3-RR) in alkaline conditions to alleviate the growing energy demand and environmental pollution. Cu/Ni(OH)2 demonstrate an enhanced electrochemical performance. It is found that the synergistic effect between Cu nanosphere and Ni(OH)2 nanosheet can improve NO3-RR dynamics with high Faradaic efficiency (91.90%), NH3 selectivity (92.10%) and long durability.

Porous rod-like structured ternary nitride heterocatalyst Co3Mo3N/Ni3Mo3N for efficient and stable hydrogen evolution reaction

Heterostructure electrocatalysts have garnered widespread attention for effectively enhancing electrocatalytic activity. However, less attention has been paid to ternary nitride heterostructure catalysts for the hydrogen evolution reaction (HER), and their synthesis remains challenging. In this study, a Co3Mo3N/Ni3Mo3N heterostructure catalyst on nickel foam (NF) is designed and prepared via high-temperature nitridation of the heterostructured precursor. The resulting 1D/3D hierarchical structure electrode, featuring rich heterointerfaces, provides abundant active sites, enhancing mass transport and charge transfer. Experimental results reveal strong electronic interactions at the heterointerface, while density functional theory (DFT) calculations establish that Co3Mo3N/Ni3Mo3N possesses a lower water dissociation energy barrier and optimized hydrogen adsorption energy. Consequently, it demonstrates excellent HER performance, exhibiting low overpotentials of 36 mV in alkaline and 58 mV in neutral media at 10 mA cm−2. This study presents an innovative approach to designing ternary nitride heterostructure catalysts with enhanced HER activity, applicable to other heterostructure catalysts.

A method for measuring serum levels of melanin-associated indole metabolites using LC-MS/MS and its application to malignant melanoma

Background and aimsWith the development of novel therapies for advanced malignant melanoma (MM), biomarkers that can accurately reflect the progression of MM are needed. Serum levels of melanin-related indole metabolites such as 5-hydroxy-6-methoxyindole-2-carboxylic acid (5H6MI2C) and 6-hydroxy-5-methoxyindole-2-carboxylic acid (6H5MI2C) are potential biomarkers for MM. Here, we describe the development of a mass spectrometry (MS)-based assay to determine serum levels of 5H6MI2C and 6H5MI2C. Materials and methodsWe developed a stable isotope dilution-selective reaction monitoring-MS protocol using liquid chromatography tandem mass spectrometry (LC-MS/MS) to measure human serum 5H6MI2C and 6H5MI2C levels. Analytical evaluations of the method were performed and the method was applied to serum samples from MM patients (n = 81). ResultsThe method established in this study showed high reproducibility and linearity. This novel method also found that serum 6H5MI2C levels were significantly elevated in patients with metastatic MM compared to those with non-metastatic MM. Unfortunately, 5H6MI2C did not show a comparable significant difference. ConclusionWe successfully established measurement methods for serum 5H6MI2C and 6H5MI2C levels using LC-MS/MS. Serum 6H5MI2C levels offer a potential marker for MM.

Constructing high coordination number of Ir-O-Ru bonds in IrRuOx nanomeshes for highly stable acidic oxygen evolution reaction

Constructing high coordination number of Ir-O-Ru bonds in IrRuOx nanomeshes for highly stable acidic oxygen evolution reaction

Balance and imbalance in biogeochemical cycles reflect the operation of closed, exchange, and open sets

Biogeochemical reactions modulate the chemical composition of the oceans and atmosphere, providing feedbacks that sustain planetary habitability over geological time. Here, we mathematically evaluate a suite of biogeochemical processes to identify combinations of reactions that stabilize atmospheric carbon dioxide by balancing fluxes of chemical species among the ocean, atmosphere, and geosphere. Unlike prior modeling efforts, this approach does not prescribe functional relationships between the rates of biogeochemical processes and environmental conditions. Our agnostic framework generates three types of stable reaction combinations: closed sets, where sources and sinks mutually cancel for all chemical reservoirs; exchange sets, where constant ocean-atmosphere conditions are maintained through the growth or destruction of crustal reservoirs; and open sets, where balance in alkalinity and carbon fluxes is accommodated by changes in other chemical components of seawater or the atmosphere. These three modes of operation have different characteristic timescales and may leave distinct evidence in the rock record. To provide a practical example of this theoretical framework, we applied the model to recast existing hypotheses for Cenozoic climate change based on feedbacks or shared forcing mechanisms. Overall, this work provides a systematic and simplified conceptual framework for understanding the function and evolution of global biogeochemical cycles.

Stable hydrogen evolution reaction at high current densities via designing the Ni single atoms and Ru nanoparticles linked by carbon bridges

Continuous and effective hydrogen evolution under high current densities remains a challenge for water electrolysis owing to the rapid performance degradation under continuous large-current operation. In this study, theoretical calculations, operando Raman spectroscopy, and CO stripping experiments confirm that Ru nanocrystals have a high resistance against deactivation because of the synergistic adsorption of OH intermediates (OHad) on the Ru and single atoms. Based on this conceptual model, we design the Ni single atoms modifying ultra-small Ru nanoparticle with defect carbon bridging structure (UP-RuNiSAs/C) via a unique unipolar pulse electrodeposition (UPED) strategy. As a result, the UP-RuNiSAs/C is found capable of running steadily for 100 h at 3 A cm−2, and shows a low overpotential of 9 mV at a current density of 10 mA cm−2 under alkaline conditions. Moreover, the UP-RuNiSAs/C allows an anion exchange membrane (AEM) electrolyzer to operate stably at 1.95 Vcell for 250 h at 1 A cm−2.

Highly efficient Ni3Se2@sintering porous Ni catalytic electrode for durable hydrogen evolution reaction

The development of cheap, efficient, and long-term stable hydrogen evolution reaction (HER) electrocatalysts is indispensable but still challenging for large-scale industrialized water electrolysis. Recently, many studies have shown that in-situ selenization of metal matrixes is expected to improve the catalytic activity of the metal-based electrodes. In the present work, optimal nickel matrix with controlled polygonal morphology and pore size was obtained by adjusting the sintering process. A highly efficient Ni3Se2@sintered Ni electrode was acquired by in-situ growing nano-Ni3Se2 on sintered Ni matrix using one-step hydrothermal selenization. The metallurgical bonding between Ni particles accelerates electron transfer, and nano-Ni3Se2 provides more active sites. As a consequence, the prepared Ni3Se2@Ni500 electrode can operate stably at current density of 200 mA cm−2 over 260 h. The excellent hydrogen catalytic performance and long-term stability make such electrode promising in the hydrogen evolution reaction.

Enabling High Performance Bismuth Trifluoride Cathode by Engineering the Cathode/Electrolyte Interface in Sulfide‐Based All Solid State Batteries

AbstractMetal fluorides are conversion‐type cathodes that have the potential to boost the energy densities of next generation lithium‐ion batteries (LIBs). However, the study of non‐transitional metal fluorides (NTMFs) such as bismuth trifluoride (BiF3) is limited due to the challenges on the construction of a stable electrochemical reaction interfaces with liquid electrolyte, although it shows advantages on high electrochemical potential, moderately high theoretical capacity and low voltage hysteresis. Moreover, the performance of BiF3 in all solid state batteries (ASSBs) has not been explored. In this contribution, the micro‐sized commercial BiF3 is successfully coated with a cyclic polyacrylonitrile (cPAN) and refined its size to nanoscale. The refined nano‐sized BiF3@cPAN uniformly disperses in the solid electrode and delivers an initial discharge capacity of 330 and 200 mAh g−1 after 250 cycles in sulfide electrolyte based ASSBs. Furthermore, the voltage hysteresis of the ASSBs reaches a record low value of 180 mV. Postmortem analysis shows that the elastic coating hindered the undesirable interface side reaction and rendered the BiF3 with excellent cycle reversibility. This work demonstrates the crucial role of stable interfaces for BiF3 in preventing electrolyte decomposition, which promotes the practical adoption of BiF3 cathode with higher specific energy for LIBs.