This study introduces innovative advancements in catalyst and membrane technology to improve fuel cell performance and reduce costs. Platinum-group metal (PGM)-free iron-nitrogen-carbon (Fe-N-C) catalysts achieved a 0.85 W/cm2 power density, a 19.88% improvement over traditional PGM-free catalysts, with stable operation exceeding 1000 hours. Nanostructured carbon supports enhanced oxygen reduction reaction activity by 30.13% and current density by 25.02%. Additionally, a novel proton exchange membrane with superior ionic conductivity and durability increased fuel cell efficiency by 10.12% while significantly reducing hydrogen crossover rates. These advancements represent a breakthrough in developing cost-effective, high-performance fuel cell systems.

The synthesis of electrolytes based on nanopowders of Zr₀.₈₄Y₀.₁₆O₂-δ (YSZ), Zr₀.₈₁Sc₀.₁₉O₂-δ (ScSZ), and Ce₀.₇₃Gd₀.₂₇O₂-δ (GDC) was carried out using laser evaporation. The resulting powders had average particle sizes of 15.5 μm (YSZ), 11.0 μm (ScSZ), and 0.02 μm (GDC), as determined by BET analysis. The specific surface areas of the powders were 65.3 m²/g for YSZ, 97.4 m²/g for ScSZ, and 34.2 m²/g for GDC. Additionally, cathode material powders of La₀.₇Sr₀.₃MnO₃ (LSM) and lanthanum strontium cobalt ferrites (LSCF-2020, LSCF-4020, and LSCF-4080) were synthesized using polymer-salt pyrolysis and solution combustion synthesis methods. The LSM powder exhibited a rhombohedral phase (space group R-3c) with a secondary phase content of ~9 wt.%. The LSCF powders demonstrated a single-phase perovskite structure with a rhombohedral symmetry (space group R-3c). Nickel oxide (NiO) powder for the anode was obtained using the wire explosion method, producing predominantly spherical particles. The phase composition of the synthesized materials was determined using X-ray diffraction (XRD), confirming a single-phase structure for all powders except LSM, which contained ~9 wt.% of a secondary phase. The sintering behavior was studied to determine optimal processing conditions, revealing that the electrolytes reached high densification levels at 1300°C, while the electrodes required sintering at 1100–1150°C. The co-sintering approach was developed for fabricating solid oxide fuel cells (SOFCs), allowing for controlled morphology of polymer-ceramic films. Electrochemical performance tests demonstrated the long-term stability and functional viability of the fabricated solid oxide fuel cells components.

This study numerically optimizes energy harnessing in vehicle engines using three heat exchanger fin designs: wall to wall, pyramid, and hexagonal. Two thermoelectric generator (TEG) array configurations are compared for electrical power generation. Results show the wall-to-wall fin provides the highest heat transfer, producing 161 W of power from 13 590.53 W of heat. Both TEG configurations generate similar output, with the series offering slightly higher voltage. The flow direction has minimal impact, but increasing the number of heat exchangers boosts efficiency. The total system output reaches 27 763.60 W with a four-parallel exchanger setup and an efficiency of 1.72.

Solid oxide fuel cells (SOFCs) offer high efficiency and fuel adaptability but face challenges like high operating temperatures and material degradation. This study focuses on innovative solutions, including doped ceria-based electrolytes with ionic conductivity of 0.1 S/cm at 600 degrees C, reducing operating temperature by 200 degrees C and extending lifespan by 29.15%. Composite anodes with hierarchical pores achieved a power density of 1.2 W/cm(2) (25% improvement) and maintained stability over 5000 h with <1% degradation per 1000 h. Hybrid integration with micro gas turbines improved efficiency to 69.48% (14.28% increase) and cut CO2 emissions by 21%, advancing SOFC viability as sustainable energy solution.

Conventional solvents remain the most used media for lignocellulosic biomass valorization. However, these solvents exhibit many limitations and have a negative environmental impact. In the last decade, Deep Eutectic Solvents (DESs) have emerged as a multifaceted tool in biomass valorization, with a promising perspective in the application of lignocellulosic biomass valorization. DESs have gained attention in the last decade as an alternative solvent in biomass valorization and biorefinery processes due to their high efficiency; eco-friendliness; low cost; and numerous other advantages, such as recyclability, non-volatility, and stability. This paper discusses the latest research on the potential applications of DESs in the valorization of secondary lignocellulosic biomass.

This study investigates the hydrogen adsorption performance of activated carbon (AC) derived from rice husks and modified with magnesium and nickel salts. Adsorption isotherms were recorded at 25 °C and 50 °C up to 80 bar, simulating practical storage conditions. The unmodified AC exhibited the highest hydrogen uptake (0.62 wt% at 25 °C), attributed to its high surface area and dominant ultramicroporosity (<0.9 nm). Modifications with Mg and Ni reduced adsorption capacity, likely due to partial pore blockage and decreased surface functionality, as confirmed by FTIR, Raman, and XRD analyses. Despite this, all samples demonstrated stable cyclic adsorption–desorption behavior and consistent isotherm profiles. Hysteresis observed in the modified samples suggests capillary condensation within mesopores. Thermodynamic analysis confirmed the exothermic nature of hydrogen adsorption. Among the modified materials, ACM10 (Mg-modified) exhibited the best performance (0.54 wt%), highlighting the importance of optimizing the metal content. The obtained results indicate that the micropore size distribution and accessible surface functionality critically govern the hydrogen storage capacity, suggesting that unmodified AC is a promising candidate for low-temperature hydrogen storage systems.

Copper chalcogenides have a complex electronic structure due to the interaction of hybridized s- and p-states of chalcogen forming a valence band with 3d states of copper, which greatly complicates the interpretation of temperature dependences of kinetic parameters having a nonmonotonic character. Cu2S copper sulfide is an effective thermoelectric material, so it is interesting to study its kinetic parameters of solid solutions that it forms with alkali metals. The nonstoichiometry of chalcogenides can be easily controlled electrochemically, therefore, the task of selecting the optimal composition according to the cationic sublattice is quite feasible. The paper presents experimental studies of the properties of Cu2S binary copper sulfide. Copper chalcogenides have a complex electronic structure due to the interaction of hybridized s- and p-states of chalcogen forming a valence band with 3d states of copper, which greatly complicates the interpretation of temperature dependences of kinetic parameters having a nonmonotonic character. For the Cu2S sample, rather low values of the electron thermal EMF coefficient of the sample from 0.05 mV/K to 0.25 mV/K were found, which are more typical for metals than for semiconductors. The thermal conductivity of the Cu2S sample is quite low, it rises to 0.3 W/m*K at a phase transition of about 380 K and does not fall below 0.2 W/m*K. Thus, the nonstoichiometry of chalcogenides can be easily controlled electrochemically, therefore, the task of selecting the optimal composition according to the cationic sublattice is quite feasible. In addition, to improve the thermoelectric properties of Cu2S, it can be achieved by alloying alkali metals into a binary copper sulfide matrix.

Solid oxide fuel cells (SOFCs) are efficient electrochemical energy device that converts the chemical energy of fuels directly into electricity. It has a high power and energy density and a sustainable source of energy. The electrode (cathode and anode) materials are essential for the efficient operation of SOFCs. Several electrode materials have been studied in the last two decades, mainly perovskite materials. The investigated materials have resulted in improved electrochemical performance of SOFCs, increased commercial viability, and reduced operational costs. However, the sustainability of most of the material compositions (heteroatoms) used as electrodes in SOFCs has never been investigated. The present study examines the recent progress, challenges, and constraints associated with electrode material development in SOFCs from a sustainable perspective. Heteroatoms majorly employed for doping in electrode materials’ long-term availability on the earth’s surface was established. The study also provides an overview on the current state of electrode materials development for symmetrical solid oxide fuel cells. This is intended to address the complexities of different materials development for the anode and cathode

The paper presents experimental results of concentration polarization and ionic conductivity of nanocomposite thermoelectric materials K0.01Cu1.94S , K0.02Cu1.94S , K0.03Cu1.94S . According to X-ray phase analysis, the synthesized samples are monoclinic jarleite Cu1.93÷1.97S with an admixture of oxygen oxide Cu2S and monoclinic chalcocyte. High values of total ionic conductivity are observed, ranging from 0.86 to 1.5 Cm/cm. The lowest ionic conductivity (0.86 Cm/cm at 355 ◦ C) is observed for alloy K0.02Cu1.94S . In addition, it was found that with an increase in the concentration of potassium in the studied materials, ionic conductivity tends to decrease, activation energy increases, but the characteristics of ion transport remain high, corresponding to superionic materials.

BaFeO-based hexaferrite compounds were synthesized by partially replacing Fe atoms with In atoms in barium hexaferrite, and their structural characteristics, thermal, and magnetic properties were studied. The crystal structure and lattice parameters of the hexaferrite were investigated using the X-ray diffraction method. Thermal property investigations were conducted at high temperatures. The results obtained by the Differential Scanning Calorimetry (DSC) method were analyzed, and the mechanisms of formation and decomposition of hydroxide groups in these crystals were explained. These effects were also determined by Thermogravimetric Analysis (TGA) studies. The vibrational magnetometry method studied the magnetic properties of BaFe11.4In0.6O19 and BaFe10.8In1.2O19 compounds. As the concentration of In atoms in the samples increases, the temperature of the ferrimagnetic-paramagnetic phase transition decreases. The observed effect in the temperature range of RT to 800 degrees C is attributed to weight loss due to the decomposition of structural water molecules through an endothermic reaction in hexaferrite compounds. The value of the Curie temperature for the BaFe11.4In0.6O19 compound was 383 degrees C, and for the BaFe10.8 In1.2O19 compound, it was 323 degrees C. Increasing In concentration from x = 0.6 to x = 1.2 increases the In3+ ionic radius in the structure, and due to the replacement of Fe3+ ions with more In3+ ions at x = 1.2, the magnetic hyperfine field area decreases.

An experiment was conducted for studying the cluster structure of Be induced by He ions at an energy of 30 MeV. As results of the nuclear reaction 3He + 9Be, the differential cross sections for the exit channels – elastic, inelastic, α + 8Be, 6He + 6Be, 6Li + 6Li, and 7Be + 5He – were measured. Elastic and inelastic scattering data were treated within both the optical model and coupled channel method. A new set of optical potentials was considered for the elastic scattering. The deformation parameter was established for the transition . Cluster transfer reactions were analyzed via the coupled reaction channel method. The nuclear reactions with the exit channels 6He + 6Be, 6Li + 6Li, and 7Be + 5He were complemented by two-step transfer mechanisms. The contribution of each reaction mechanism were shown and compared with the findings of other authors.

The present study is devoted to the fabrication of an anode supported microtubular solid oxide fuel cell (MTSOFC) by co -sintering of polymer -ceramic films set. The investigation of the influence of the granulometric composition of Zr0.84Y0.16O2-delta (YSZ), Ce0.73Gd0.27O2-delta (GDC) powders and NiO/YSZ, NiO/GDC composites on the kinetics of their sintering made it possible to obtain a defect -free half -cell of anode supporting layer (NiO/YSZ)anode functional layer (NiO/GDC) - YSZ electrolyte in a single sintering act at 1200 degrees C. The influence of a pore former (rice starch) on the microstructure of the anode supporting layer was studied. It was shown that the addition of 5 wt% pore former results in an increase of the porosity and gas permeability of the layer by -1.6 and -4 times, respectively. Layers of the second GDC electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) cathode were applied sequentially by dip -coating and painting and were sintering at 1450 and 1200 degrees C, respectively. The maximum specific power of the obtained MT-SOFC at 850 degrees C was 184 mW/cm2.

Intermediate-temperature solid oxide fuel cell (IT-SOFC) work at moderate temperature range (600—800 ℃), thereby eliminating the issue of thermal degradation of electrode materials, reduce operational cost, increase flexibility of material selections, and enhance electrochemical stability of cell components. At intermediate-temperature range, there exists sluggish cathodic reaction, high activation energy and slow oxygen reduction reaction (ORR) at the cathode. Several cobalt-containing cathode perovskite materials with mixed ionic and electronic properties have been developed, which has helped in resolving sluggish ORR and enhances cathodic reaction, thereby increasing the overall performance of IT-SOFC. The expensive nature of cobalt, high evaporation rate and poor thermal expansion coefficient (TEC) means cobalt-free cathode materials need to be investigated. The present study gives an insight into the current trends of cobalt-free cathode materials development in IT-SOFC. Literature reviewed showed composite La0.65Ca0.35FeO3-δ-Gd0.2Ce0.8O2-δ (LCF-GDC), and La0.7Sr0.3Cu0.15Fe0.85O3-δ cathode materials has good polarisation resistance of 0.28 Ωcm2 at 750 ℃, and 0.0153 Ωcm2 at 700 ℃, respectively. Limitations, challenges, gaps were identified, and possible future research direction was recommended. The study also analysed the use of symmetrical electrodes, as it will help resolve the complexity of developing different electrode materials for cathode and anode in IT-SOFC. Holistic efforts were devoted to ensuring that the literature reviewed was recent (within the last 4yrs), and relevant to the current constraints impeding cathode materials use in IT-SOFC. This review study is meant to serve as a reference material to related researchers, and industry experts looking for the most recent accomplishments in cobalt-free cathode materials development.

BaFeO-based hexaferrite compounds were synthesized by partially replacing Fe atoms with In atoms in barium hexaferrite, and their structural characteristics, thermal, and magnetic properties were studied. The crystal structure and lattice parameters of the hexaferrite were investigated using the X-ray diffraction method. Thermal property investigations were conducted at high temperatures. The results obtained by the Differential Scanning Calorimetry (DSC) method were analyzed, and the mechanisms of formation and decomposition of hydroxide groups in these crystals were explained. These effects were also determined by Thermogravimetric Analysis (TGA) studies. The vibrational magnetometry method studied the magnetic properties of BaFe11.4In0.6O19 and BaFe10.8In1.2O19 compounds. As the concentration of In atoms in the samples increases, the temperature of the ferrimagnetic-paramagnetic phase transition decreases. The observed effect in the temperature range of RT to 800°C is attributed to weight loss due to the decomposition of structural water molecules through an endothermic reaction in hexaferrite compounds. The value of the Curie temperature for the BaFe11.4In0.6O19 compound was 383°C, and for the BaFe10.8 In1.2O19 compound, it was 323°C. Increasing In concentration from x=0.6 to x=1.2 increases the In3+ ionic radius in the structure, and due to the replacement of Fe3+ ions with more In3+ ions at x=1.2, the magnetic hyperfine field area decreases.

This comprehensive study explores groundbreaking innovations in the realm of solid oxide FCs (SOFCs) with a particular emphasis on fuel cell (FC) modeling, parametric analysis, and performance evaluation. The research delves into the intricate dynamics of a hydrogen-powered tubular SOFC, dissecting various parameters that influence its operation and efficiency. Innovation lies in the meticulous examination of how temperature, FC operating pressure, air flow rate to fuel input ratio, and wider gas channels impact FC efficiency and power production. The study employs a distinctive electrochemical approach to scrutinize pile factors and their effects on efficiency, shedding light on the interplay of fuel efficiency factor, current density, and actual voltage. Notably, the study introduces a novel approach by setting the current density to 7030 A/m2 and the efficiency factor to 0.7, leading to a substantial enhancement in FC efficiency and power output. Furthermore, the research delves into the optimization, electrochemistry, and thermal dynamics of SOFCs, conducting a thorough comparison of current findings with reliable sources to ensure accuracy and reliability. Results indicate a substantial improvement in fuel efficiency, current density, and actual voltage, resulting in increased FC efficiency and power output. The study observes a consistent decrease in fuel usage across various scenarios. Additionally, the research dispels concerns about the impact of lowering inlet temperature on channel temperature disparity, providing valuable insights for the advancement of SOFC technology.

Efficient cathode materials are essential to the overall cell performance of solid oxide fuel cell (SOFC). The high linear thermal expansion coefficient (TEC) of traditional cobalt-containing cathode materials, cobalt poisoning, and the expensive nature of cobalt mean that cobalt-free cathode materials must be examined. Sr-doped cobalt-free BaZr0.8Ni0.2O3-δ cathode materials were synthesised using the conventional solid-state reaction method, and investigated as potential cathode materials for SOFC application. The synthesised Ba1-xSrxZr0.8Ni0.2O3-δ (BSZN0, BSZN25, BSZN5; x = 0, 0.25 and 0.5) samples were characterized via X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, dilatometer, and electrochemical impedance spectroscopy. The XRD analysis of the synthesised samples revealed a well-defined peak position at 2theta, and indexed as pm-3 m cubic space group. At 800 °C, the electrical conductivity in air for BSZN0, BSZN25, and BSZN5 were 72.24 S/cm, 80.46 S/cm and 85.55 S/cm, respectively. The average linear thermal expansion coefficient obtained for BSZN0, BSZN25, and BSZN5 at 25 to 1000 °C were 10.4 × 10–6 K−1, 10. 9 × 10–6 K−1, and 11.2 × 10–6 K−1, respectively. The improved linear thermal elongation of BSZN0, BSZN25, and BSZN5 will ensure compatibility with commonly used electrolytes in SOFCs.

The global imperative to reduce greenhouse gas emissions and phase out fossil fuels has prompted hydrogen to emerge as a critical player in the transition to sustainable energy systems and eco-friendly transport solutions. This study endeavors to examine innovative technologies for hydrogen production and storage, with the objective of overcoming the obstacles that impede their widespread adoption. The integration of hydrogen with renewable energy sources is one of the methods that have been investigated. Specifically, the effectiveness of coupling hydrogen fuel cells with wind or solar power systems has been examined in order to ensure a reliable energy supply and improve grid stability. The results of this study present innovative methods for mass hydrogen production, including electrolysis of water and advanced techniques for extracting hydrogen from fossil fuels while minimizing environmental impact. Additionally, this study evaluates strategies for underground hydrogen storage, considering local geological conditions to optimize storage efficiency and safety. The findings indicate that salt caverns offer a secure and stable hydrogen containment system and have a high storage efficiency of up to 90%. The evaluation of depleted gas fields demonstrated promising results in terms of sealing integrity and storage efficiency (88%). The outcomes provide insights into the feasibility of large-scale hydrogen generation and storage, offering valuable guidance for future energy solutions dependent on hydrogen in diverse geographic contexts.

The utilization of bio-hydrogen as a fuel source holds immense promise as a renewable energy option, offering compelling economic and environmental advantages. This study investigates the economic and environmental advantages of bio-hydrogen as a renewable energy source compared to fossil fuels, focusing on the reduction of greenhouse gas emissions such as carbon dioxide and carbon monoxide. The enhancement of anaerobic hydrogen production reactor capacity is explored through the application of a fuzzy controller system. Numerical simulations demonstrate that the fuzzy controller outperforms other methods in augmenting biological hydrogen production, effectively addressing the inherent non-linear characteristics of the system. In contrast, limitations in robustness against system uncertainty are observed with the non-linear controller. Exceptional tracking of desired values by the fuzzy controller, even in the presence of model uncertainty, results in a lower integral of time multiplied by squared error (ITSE) performance index compared to non-linear and proportional-integral controllers. Emphasizing the viability of the fuzzy method for regulating hydrogen production processes, potential gains of up to 95% in biological hydrogen production are indicated compared to open-loop configurations. This clean-burning fuel holds promise for industrial applications, contributing to the reduction of harmful gas emissions. The findings underscore the transformative potential of the fuzzy controller system in advancing sustainable hydrogen production and its significant role in addressing environmental concerns.

Kazakhstan possesses significant natural resources, including coal, oil, natural gas, and uranium, and also has substantial potential for utilizing renewable energy sources such as wind, solar, hydropower, and biomass. However, the country currently relies heavily on fossil fuels for electricity generation. Coal-fired power plants account for 75% of the total electricity production, raising concerns about greenhouse gas emissions and their detrimental impact on human health and the environment. In December 2020, at the Climate Ambition Summit, the President of Kazakhstan announced a new goal for the country to achieve carbon neutrality by 2060. To attain this objective, the government faces the ambitious task of developing a strategy for the development of hydrogen energy in Kazakhstan. This review extensively discusses Kazakhstan's main energy resources, the potential for low-car-bon and green hydrogen production, existing and prospective pilot projects in the field of hydrogen, as well as the challenges and barriers hindering the development of hydrogen energy in Kazakhstan. Authors consider existing research, national reports, energy strategies, and plans to discuss the prospects for hydrogen energy development in Kazakhstan. The transition to hydrogen energy in Kazakhstan requires the development of a comprehensive roadmap that takes into account various aspects such as production, infrastructure development, policy support, and international cooperation. Currently, the country lacks a roadmap for hydrogen energy development that considers these crucial aspects. Therefore, as a result of this review, we have developed a new roadmap for hydrogen production by 2040 in Kazakhstan, incorporating various technologies. Authors believe this roadmap will be valuable information for the government to develop a national strategy for the active development of hydrogen energy in Kazakhstan.