Search Results (31)

Coupling renewable energy with seawater electrolysis is a highly promising strategy for sustainable hydrogen production. However, the practical application of direct seawater electrolysis remains challenging due to severe anode corrosion and the competitive chlorine evolution reaction (CER) induced by chloride ions. Herein, we report a facile cation-etching strategy to synthesise Fe@ZIF-67 catalysts at room temperature, using ZIF-67 as the sacrificial template and Fe²⁺ salts as the etching agent. The as-prepared Fe@ZIF-67 exhibits superior electrocatalytic activity for the oxygen evolution reaction (OER) in a simulated alkaline saline electrolyte (1.0 M KOH + 0.5 M NaCl). Specifically, it achieves a current density of 10 mA cm⁻² at a low overpotential of 259 mV, outperforming commercial RuO₂. Furthermore, an alkaline saline electrolyser assembled with Fe@ZIF-67 as the anode and Pt/C as the cathode requires a cell voltage of only 1.57 V to reach 10 mA cm⁻², which is significantly lower than that of the RuO₂||Pt/C benchmark (1.65 V). This work demonstrates that the cation-doping strategy effectively modulates the surface electronic structure of metal–organic frameworks (MOF)-based catalysts, providing a new perspective for optimising their performance in seawater electrolysis. Full article

Slow reaction kinetics of the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) under alkaline conditions limits the performance of anion exchange membrane fuel cells and water electrolysers (AEMFC and AEMWE). Consequently, high loadings of PGM metal-based compounds such as Pd-CeO₂ and PtRu are required to obtain competitive performance. The amount of precious metals present can be reduced by exploiting interaction with an active support material that tunes both hydrogen desorption and hydroxyl adsorption, processes that are key descriptors of HOR activity. In this work, NiWO_3−xC is prepared, composed of oxygen-deficient tungsten oxide (WO_3−x) doped with Ni nanoparticles and mixed with conductive carbon (50:50 wt%). This material is decorated with Pd nanoparticles (6.6 wt% Pd loading). Structural analysis (XRD, XPS, and HR-TEM/STEM) confirm a hybrid morphology of Pd nanoparticles deposited on both the Ni and W portions of the support. The HOR and HER activity was studied using electrochemical tests and compared to the performance of both a Pd/C standard with equivalent Pd loading (6.9 wt%) and the NiWO_3−xC support. The Pd-normalized exchange current densities for the HOR (I⁰) are 18.7 A g_Pd⁻¹ for Pd/NiWO_3−xC and 3.21 A g⁻¹ for Pd/C. The enhanced HOR activity of Pd/NiWO_3−xC translates to high power densities in AEM fuel cell tests with this catalyst applied to the anode electrode (up to 0.9 W cm⁻²). Full article

Experimental alkaline water electrolysis (AWE) systems require precise thermal management to achieve stable electrochemical efficiency. Manual operation of laboratory-scale electrolysers often induces thermal fluctuations that lead to excessive overpotentials. In this work, a real-time data acquisition (DAQ) and automated temperature-control architecture were implemented in a 3 kW nominal alkaline electrolyser in order to observe the thermal stability regime. The system was evaluated using a stepped-current protocol derived from FCTESTNET standards. Current densities of 0.3 and 0.5 A·cm⁻² were investigated, corresponding to operating currents of approximately 22.5 A and 40 A, respectively. Variations in manually controlled conditions raised temperature values to near 100 °C. With the implemented control system, two distinct thermal regimes were observed. At 0.3 A·cm⁻², cyclic behaviour between 60 and 80 °C was recorded due to on–off cooling dynamics. At 0.5 A·cm⁻², the system reached a stable thermal regime between 70 and 75 °C, maintaining steady-state fluctuations within ±1 °C after transient stabilisation. It was observed that the electronically controlled thermal system reduced temperature-induced overpotentials and improved voltage stability during long-duration tests. The results demonstrate that integrating automated thermal control enhances operational safety and enables reproducible electrolyser evaluation under controlled laboratory conditions. Full article

This study details the design, fabrication, and experimental validation of three unique alkaline electrolysers, each featuring a modified internal electrode-support geometry. Their performance was comprehensively assessed through polarisation curve analysis in individual, partial, and global configurations. The development followed the Advanced Product Quality Planning (APQP) methodology, employing pure nickel electrodes to ensure stability. The results demonstrate that specific geometric alterations directly influence electrochemical performance and overall efficiency. By operating three electrolysers simultaneously, the system achieved an overall efficiency of 42% and a maximum oxyhydrogen production rate of 10 L·min⁻¹, with minimal electrolyte carryover. This systematic work establishes essential design guidelines to advance the technology from Technology Readiness Level (TRL) 5 to TRL 6, facilitating the development of a reliable 5 kW hydrogen production system. Full article

This study develops and applies an integrated modeling framework to assess the solar-to-hydrogen-to-power potential across Romania’s five hydrogen ecosystems defined in the National Hydrogen Strategy. The methodology couples PVGIS-based photovoltaic yield simulations, based on hourly solar irradiation data and including system losses, with MHOGA-based electrolysis simulation, enabling a quantitative-energetic-environmental (Q-E-E) system-level assessment. A 1 MW photovoltaic plant was simulated under three mounting configurations (15° fixed tilt, optimal tilt, and solar tracking) and interfaced with alkaline (AEL) and proton exchange membrane electrolysers (PEMEL). Specific photovoltaic yields reach up to 360 kWh/m²_PV·year under tracking conditions, producing up to 7.5 kg/m²_PV·year (AEL) and 6.8 kg/m²_PV·year (PEMEL), expressed per unit of photovoltaic surface area to enable consistent comparison across the configurations considered. The modeled round-trip efficiency of the full solar–electricity–hydrogen–electricity chain is 38.32% for AEL and 34.57% for PEMEL. Life-cycle-based emission modeling yields 0.92 kg CO₂/kg H₂ (AEL) and 1.03 kg CO₂/kg H₂ (PEMEL), while avoided emissions exceed 250 g CO₂/kWh relative to grid intensity. Land-use modeling indicates area requirements between 9402 and 18,804 m²/MW, depending on the Ground Coverage Ratio. Results demonstrate that system configuration exerts a stronger influence than regional solar variability in determining hydrogen yield, highlighting the need for integrated techno-environmental optimization for large-scale deployment. Full article

Direct solar photovoltaic to electrolyser systems offer a promising pathway for producing low-carbon hydrogen, yet their performance and scalability remain limited by challenges that arise when variable solar generation is coupled to electrochemical conversion, with unresolved implications for electrolyser lifetime and hydrogen production cost. This review synthesises recent advances in photovoltaic technologies, electrolyser development and emerging deployment configurations to evaluate the technical, operational and environmental factors that shape system feasibility. The assessment draws on findings from experimental studies, modelling frameworks and techno-economic analyses to examine photovoltaic efficiency losses, thermal and material degradation, high-resolution intermittency effects, electrolyser dynamics, degradation mechanisms and storage interactions, and their combined influence on usage-dependent lifetime and cost behaviour. The results show that fluctuating solar input reduces conversion efficiency, increases transient overpotentials and accelerates degradation in both photovoltaic modules and electrolyser stacks. Technology-specific trade-offs persist, with alkaline water electrolysis constrained by limited flexibility, proton exchange membrane electrolysis by reliance on scarce catalyst materials, and anion exchange membrane and solid oxide electrolysis systems requiring further validation under real-world variability. Floating photovoltaic systems and agrivoltaics expand deployment opportunities but introduce additional constraints related to water quality, ecological impacts and power variability. Overall, the review finds that system-level integration, dynamic modelling, degradation-aware design and coordinated storage strategies are essential to unlocking reliable and scalable solar-to-hydrogen production. Full article

Renewable intermittency forces electrolytic hydrogen systems to operate across multiple states, lowering efficiency. We design a thermodynamic cycle that recovers electrolysis waste heat and integrates it with an alkaline electrolyser. A detailed thermodynamic model of the hydrogen system and the heat-recovery loop is developed, and design and operating parameters are optimized to maximize overall exergy efficiency. To improve economic viability, heat-exchanger structural parameters are co-optimized. We further propose an optimal scheduling method for the heat-recovery system under fluctuating renewable supply. The method employs an interactive optimisation framework cantered on the temperature–efficiency curve of alkaline electrolyser cells, jointly optimizing electrolyser current and working-fluid mass flow to enhance economic performance. A case study using real wind-farm data from Qinghai demonstrates that the proposed system with heat recovery significantly improves performance, increasing hydrogen production by up to 9% under wind scarcity compared to that of the system without heat recovery. These results confirm the practical viability of renewable-driven hydrogen production. Full article

The global energy landscape is transitioning towards cleaner solutions, with hydrogen emerging as a key energy source. To unlock hydrogen’s potential, it is crucial to prioritize the development of a more efficient, cost-effective, and environmentally friendly production process. Enhancing the efficiency and scalability of these technologies will not only reduce their environmental impact but also accelerate the adoption of hydrogen as a viable alternative energy solution, fostering a cleaner and more sustainable future. This paper presents a study on simulating a heat recovery system in an alkaline electrolyser consisting of 30 cells, which integrates a plate heat exchanger to preheat the water entering the system, and assessing how it affects efficiency. The study uses a thermal model, employing the concept of lumped thermal capacitance, to analyze the impact of the heat recovery system utilization on the overall performance of the electrolyser. MATLAB/Simulink was used to simulate and provide a detailed visualization of how recovery systems affect the electrolyser’s efficiency. The results of the simulations confirmed that incorporating a heat recovery system significantly improves the efficiency of alkaline electrolysers up to 8%. The study provides a promising outlook for the future of hydrogen production, emphasizing the potential of waste heat recovery systems to make green hydrogen production more viable and sustainable. Full article

Background/Objectives: Hyperuricemia (HUA) is the second most common metabolic disease in China (24.5% in males, 3.6% in females), which can induce multiple complications such as gout and diabetes. Existing urate-lowering drugs have significant hepatorenal toxicity, necessitating safe lifestyle interventions. Electrolyzed alkaline water (EAW) as daily drinking water has shown preliminary effectiveness, but it lacks randomized controlled evidence and mechanistic studies at the microbiome–metabolome interface. Methods: We conducted a 12-week randomized controlled trial in 40 adults aged 18–65 years with elevated serum uric acid (SUA). Participants consumed either 1.5 L/day of EAW (pH 8.5–9.5) or purified water (pH 7.0). Clinical indicators, quality of life (SF-36), gut microbiota, and gut metabolomics were comprehensively assessed to evaluate intervention efficacy and explore potential mechanisms. Results: After 12 weeks, the EAW group exhibited a larger reduction in serum uric acid than the control group, along with improvements in selected physical health-related quality-of-life measures. Modest differences in gut microbial composition were observed between groups. Metabolomic analyses identified group-level differences in metabolites enriched in pathways related to purine metabolism and other urate-associated metabolic processes. Conclusions: This pilot randomized controlled trial suggests that consumption of EAW is associated with a modest reduction in serum uric acid. Exploratory multi-omics analyses indicate concurrent changes in gut microbiota and metabolic profiles. These findings support further investigation of electrolyzed alkaline water as a potential adjunctive, non-pharmacological option for hyperuricemia in larger and longer-term studies. Ethics: This trial was registered with the Chinese Clinical Trial Registry under the identifier ChiCTR2500100190. Ethical approval for the present study was granted by the Nankai University Institutional Review Board (NKUIRB2025001, 23 January 2025). Full article

The safety engineering design of hydrogen systems and infrastructure, worker education and training, regulatory compliance, and engagement with other stakeholders are significant to the viability and public acceptance of hydrogen farms. The only way to ensure these are accomplished is for the field of hydrogen safety engineering (HSE) to grow and mature. HSE is described as the application of engineering and scientific principles to protect the environment, property, and human life from the harmful effects of hydrogen-related mishaps and accidents. This paper describes a whole hydrogen farm that produces hydrogen from seawater by alkaline and proton exchange membrane electrolysers, then details how the hydrogen gas will be used: some will be stored for use in a combined-cycle gas turbine, some will be transferred to a liquefaction plant, and the rest will be exported. Moreover, this paper describes the design framework and overview for ensuring hydrogen safety through these processes (production, transport, storage, and utilisation), which include legal requirements for hydrogen safety, safety management systems, and equipment for hydrogen safety. Hydrogen farms are large-scale facilities used to create, store, and distribute hydrogen, which is usually produced by electrolysis using renewable energy sources like wind or solar power. Since hydrogen is a vital energy carrier for industries, transportation, and power generation, these farms are crucial in assisting the global shift to clean energy. A versatile fuel with zero emissions at the point of use, hydrogen is essential for reaching climate objectives and decarbonising industries that are difficult to electrify. Safety is essential in hydrogen farms because hydrogen is extremely flammable, odourless, invisible, and also has a small molecular size, meaning it is prone to leaks, which, if not handled appropriately, might cause fires or explosions. To ensure the safe and dependable functioning of hydrogen production and storage systems, stringent safety procedures are required to safeguard employees, infrastructure, and the surrounding environment from any mishaps. Full article

High-performance and cost-efficient electrocatalysts and electrodes are needed to improve the hydrogen evolution reaction (HER) for the hydrogen (H₂) generation in electrolysers, including microbial electrolysis cells (MECs). In this study, free-standing carbon nanofiber (CNF) films with supported cobalt phosphide nanoparticles have been prepared by means of an up-scalable electrospinning process followed by a thermal treatment under controlled conditions. The produced cobalt phosphide-supported CNF films show to be nanoporous (pore volume up to 0.33 cm³ g⁻¹) with a high surface area (up to 502 m² g⁻¹) and with a suitable catalyst mass loading (up to 0.49 mg cm⁻²). Values of overpotential less than 140 mV at 10 mA cm⁻² have been reached for the HER in alkaline media (1 M KOH), which demonstrates a high activity. The high electrical conductivity together with the mechanical stability of the free-standing CNF films allowed their direct use as cathodes in a MEC reactor, resulting in an exceptionally low voltage operation (0.75 V) with a current density demand of 5.4 A m⁻². This enabled the production of H₂ with an energy consumption below 30 kWh kg⁻¹ H₂, which is highly efficient. Full article

The study examined the potential changing roles of ports in terms of diversifying their revenue through the expansion of new markets in the Port of Ngqura. This is by means of the production and sales of renewable hydrogen as marine fuel produced from a wavefarm in Nelson Mandela Bay. A key objective of the study was to conduct a comprehensive techno-economic analysis of the feasible hydrogen production technologies based on the analysis performed, including alkaline electrolysis of seawater and renewable-powered electrolysis of seawater. The produced hydrogen aligns with global decarbonisation of ships and ports and will be used to supply the port with electricity, serve to refuel tugboats, and provide green hydrogen bunkering fuel for commercial shipping vessels. The Port of Ngqura is geographically well positioned to lead the production of zero carbon shipping fuel. This work considers the CAPEX and OPEX of a hydrogen plant using electrolysers and evaluates the current cost of production and selling price of hydrogen. The primary aim of this study was to examine the feasibility of hydrogen production through electrolysis of seawater at the Port of Ngqura. Through assessing resource and technological options, determining advantageous economic assumptions, and identifying existing limitations and potential opportunities, a feasibility study was conducted with special consideration of the site characteristics of Ngqura. The output of this study is a model that simulates the production, storage, and transportation of hydrogen gas from the Port of Ngqura, which was further used to analyse different case study scenarios. This approach directly addresses the main goal of the study. The results found showed that with wave energy convertors in a row of three next to each other, the energy produced by the wave farm was 2.973 TJ per month, which is equivalent to 18.58 tons of produced hydrogen when considering the lower heating value of hydrogen and assuming that hydrogen production efficiency is 75%. The anticipated hydrogen fuel will be able to refuel a tugboat with green hydrogen from the energy produced by the wave farm each month. It is predicted that the price of hydrogen is expected to drop, and the price of fossil fuel will gradually increase in the coming years. The fact that coal electricity can be produced on demand and wind and solar energy are weather dependent as a result lacks the ability to achieve a constant supply. There is currently an urgent need for energy storage and the efforts to study the production of hydrogen and ammonia. Hydrogen is still predicted to be more expensive than coal electricity; however, from this, maybe a critical cost for a kg of CO₂ could be calculated, which could make hydrogen competitive. The cost of green hydrogen production from wave energy in the Port of Ngqura was calculated as R96.07/kg (4.88 EUR/kg) of produced hydrogen, which is equivalent to 2.1 times the cost of the same energy supplied as Marine Diesel Oil (MDO) at current prices. Hydrogen from wave energy would thus become competitive with MDO; if a price is set for the emission of CO₂, this may also offset the difference in cost between MDO and hydrogen from wave energy. The carbon price necessary to make green hydrogen competitive would be approximately R6257/tonne CO₂, or 318 EUR/tonne CO₂, which is around 4.5 times the current trading price of carbon in the EU Emissions Trading Scheme. Full article

The application of electrochemical hydrogen evolution reaction (HER) for renewable energy conversion contributes to the ultimate goal of a zero-carbon emission society. Metal phosphides have been considered as promising HER catalysts in the alkaline environment, which, unfortunately, is still limited owing to the weak adsorption of H* and easy dissolution during operation. Herein, a bimetallic NiCoP-2/NF phosphide is constructed on nickel foam (NF), requiring rather low overpotentials of 150 mV and 169 mV to meet the current densities of 500 and 1000 mA cm⁻², respectively, and able to operate stably for 100 h without detectable activity decay. The excellent HER performance is obtained thanks to the synergetic catalytic effect between Ni and Co, among which Ni is introduced to enhance the intrinsic activity and Co increases the electrochemically active area. Meanwhile, the protection of the externally generated amorphous phosphorus oxide layer improves the stability of NiCoP/NF. An electrolyser using NiCoP-2/NF as both cathode and anode catalysts in an alkaline solution can produce hydrogen with low electric consumption (overpotential of 270 mV at 500 mA cm⁻²). Full article

This current article discusses the technoeconomics (TE) of hydrogen generation, transportation, compression and storage in the Australian context. The TE analysis is important and a prerequisite for investment decisions. This study selected the Australian context due to its huge potential in green hydrogen, but the modelling is applicable to other parts of the world, adjusting the price of electricity and other utilities. The hydrogen generation using the most mature alkaline electrolysis (AEL) technique was selected in the current study. The results show that increasing temperature from 50 to 90 °C and decreasing pressure from 13 to 5 bar help improve electrolyser performance, though pressure has a minor effect. The selected range for performance parameters was based on the fundamental behaviour of water electrolysers supported with literature. The levelised cost of hydrogen (LCH₂) was calculated for generation, compression, transportation and storage. However, the majority of the LCH₂ was for generation, which was calculated based on CAPEX, OPEX, capital recovery factor, hydrogen production rate and capacity factor. The LCH₂ in 2023 was calculated to be 9.6 USD/kgH₂ using a base-case solar electricity price of 65–38 USD/MWh. This LCH₂ is expected to decrease to 6.5 and 3.4 USD/kgH₂ by 2030 and 2040, respectively. The current LCH₂ using wind energy was calculated to be 1.9 USD/kgH₂ lower than that of solar-based electricity. The LCH₂ using standalone wind electricity was calculated to be USD 5.3 and USD 2.9 in 2030 and 2040, respectively. The LCH₂ predicted using a solar and wind mix (SWM) was estimated to be USD 3.2 compared to USD 9.6 and USD 7.7 using standalone solar and wind. The LCH₂ under the best case was predicted to be USD 3.9 and USD 2.1 compared to USD 6.5 and USD 3.4 under base-case solar PV in 2030 and 2040, respectively. The best case SWM offers 33% lower LCH₂ in 2023, which leads to 37%, 39% and 42% lower LCH₂ in 2030, 2040 and 2050, respectively. The current results are overpredicted, especially compared with CSIRO, Australia, due to the higher assumption of the renewable electricity price. Currently, over two-thirds of the cost for the LCH₂ is due to the price of electricity (i.e., wind and solar). Modelling suggests an overall reduction in the capital cost of AEL plants by about 50% in the 2030s. Due to the lower capacity factor (effective energy generation over maximum output) of renewable energy, especially for solar plants, a combined wind- and solar-based electrolysis plant was recommended, which can increase the capacity factor by at least 33%. Results also suggest that besides generation, at least an additional 1.5 USD/kgH₂ for compression, transportation and storage is required. Full article

Biomass-derived products, such as lignin, are interesting resources for energetic purposes. Lignin is a natural polymer that, when added to the anode of an alkaline exchange membrane water electrolyser, enhances H₂ production rates and efficiencies due to the substitution of the oxygen evolution reaction. Higher efficiencies are reported when different catalytic materials are employed for constructing the lignin anolyte, demonstrating that lower catalytic loadings for the anode improves the H₂ production when compared to higher loadings. Furthermore, when a potential of −1.8 V is applied, higher gains are obtained than when −2.3 V is applied. An increase of 200% of H₂ flow rates with respect to water electrolysis is reported when commercial lignin is used coupled with Pt-Ru at 0.09 mg cm⁻² and E = −1.8 V is applied at the cathode. This article provides deep information about the oxidation process, as well as an optimisation of the method of the lignin electro-oxidation in a flow-reactor as a pre-step for an industrial implementation. Full article