Publications

High-temperature proton exchange membranes (HT-PEMs) for fuel cells are considered transformative technologies for efficient energy conversion particularly in hydrogen-based transportation owing to their ability to deliver high power density and operational efficiency in harsh environments. However several critical challenges limit their broader adoption notably the limited durability and high costs associated with core components such as membranes and electrocatalysts under elevated temperature conditions. This review systematically addresses these challenges by examining the role of engineered nanomaterials in overcoming performance and stability limitations. The potential of nanomaterials to improve catalytic activity proton conductivity and thermal stability is discussed in detail emphasizing their impact on the optimization of catalyst layer composition including catalysts binders phosphoric acid electrolytes and additives. Recent advancements in nanostructured assemblies and 3D morphologies are explored to enhance fuel cell efficiency through synergistic interactions of these components. Additionally ongoing issues such as catalyst degradation long-term stability and resistance to high-temperature operation are critically analyzed. This manuscript offers a comprehensive overview of current HT-PEMs research and proposes future material design strategies that could bridge the gap between laboratory prototypes and large-scale industrial applications.

Hydrogen is a key energy carrier for decarbonizing multiple sectors particularly when produced via water electrolysis powered by renewable energy. Proton exchange membrane (PEM) electrolyzers are well suited for this application due to their ability to rapidly adjust to fluctuating power inputs. Despite being conventionally operated at high temperatures and pressures to reduce heating and compression needs recent studies suggest that under partial loads lower operating conditions may enhance efficiency. This study introduces a novel optimization framework for dynamically adjusting pressure and temperature in PEM electrolyzers. The model integrates an efficiency map within a Mixed-Integer Linear Programming (MILP) formulation and applies McCormick tightening to address nonlinearities. A one-week case study demonstrates operational cost reductions of up to 12.5 % through optimal control favoring lower temperatures and pressures at low current densities and higher temperatures near rated load while maintaining moderate pressures. The results show improved efficiency and reduced hydrogen crossover enhancing safety and enabling scalable application over extended time horizons. These insights are valuable for long-term planning and evaluation of hydrogen production and storage systems.

This comprehensive review explores silica aerogels and their application in environmental remediation. Due to rapid growth in the consumption of energy and water resources the purification of contaminated resources for use by humankind should be considered important. The primary objectives of this review are to assess the evolving landscape of silica aerogels their preparation and drying techniques and to discuss the main findings from a wide range of empirical studies and theoretical perspectives. Based on a significant amount of research this review provides information about aerogels’ capabilities as an adsorbent and catalyst. The analysis spans a variety of contexts for the generation of hydrogen and the degradation of the dyes employed in industry showing better performance in environmental remediation. The implications of this review point to the need for well-informed policies innovative synthesis strategies and ongoing research to harness the full potential for environmental management.

This work included preparing and characterizing new platinum complexes with the ligand 345 -trimethoxybenzoic acid (TMB). The reactions were carried out using a n autoclave in microwave within 3 minutes only in an alkali medium of triethylamine where two moles of TMB reacted with one mole of platinum ion and two moles of PPh 3 or with one mole of diphosphines (Bis(diphenylphosphino)x; x=methane (dppm) ethane (dppe) propane (dppp) ferrocene (dppf)). The prepared complexes were characterized by measuring melting points and by the techniques of (C.H.N) molar electrical conductivity FT -IR and 1 H -NMR. The characterization results demonstrated that the TMB ligand behaves as a bidentate ligand through the oxygen atom of the carboxylic groups and its geometric shape is a square planar around the platinum ion. The complex formed with high yield ([Pt(TMB) 2(dppf)]) was used in hydrogen storage application. The storage isotherm showed that the complex has a high storage capacity of about 4.2 wt% at 61 bar under low temperature (77 K). The study showed that the thermodynamic functions were -0.67KJ/mol and -3.6 J/mol H 2 for enthalpy and entropy indicating the occurrence of physical hydrogen storage.

To mitigate the risk of hydrogen leakage in ship fuel systems powered by internal combustion engines a Bayesian network model was developed to evaluate the risk of hydrogen fuel leakage. In conjunction with the Bow-tie model fuzzy set theory and the Noisy-OR Gate model an in-depth analysis was also conducted to examine both the causal factors and potential consequences of such incidents. The Bayesian network model estimates the likelihood of hydrogen leakage at approximately 4.73 × 10−4 and identifies key risk factors contributing to such events including improper maintenance procedures inadequate operational protocols and insufficient operator training. The Bowtie model is employed to visualize the causal relationships between risk factors and their potential consequences providing a clear structure for understanding the events leading to hydrogen leakage. Fuzzy set theory is used to address the uncertainties in expert judgments regarding system parameters enhancing the robustness of the risk analysis. To mitigate the subjectivity inherent in root node probabilities and conditional probability tables the NoisyOR Gate model is introduced simplifying the determination of conditional probabilities and improving the accuracy of the evaluation. The probabilities of flash or pool fires jet fires and vapor cloud explosions following a leakage are calculated as 4.84 × 10−5 5.15 × 10−5 and 4.89 × 10−7 respectively. These findings highlight the importance of strengthening operator training and enforcing stringent maintenance protocols to mitigate the risks of hydrogen leakage. The model provides a valuable framework for safety evaluation and leakage risk management in hydrogen-powered ship fuel systems.

Multi-energy systems (MESs) can address issues such as low renewable energy utilization and power imbalances by optimizing the integration of various energy sources. This paper proposes an optimization operation strategy for MES to regulate the hydrogen and battery storage system (HBRS) based on carbon emission factors (CEFs). Insufficient renewable energy utilization caused by reverse peak regulation can be addressed by guiding the optimal output of HBRS through this model thereby achieving multi-energy complementarity. The CEF is used to balance the output of the HBRS to achieve a low-carbon economic operating system. First the fluctuation of renewable energy is decomposed and reconstructed. Subsequently The HBRS system is utilized to smooth out the fluctuations caused by different frequencies of new energy and then the CEF is used to promote the output of the low-carbon subsystem. Finally comparative verification is conducted across validation cases to demonstrate the effectiveness of the proposed model and the optimization strategy.

This study evaluates the feasibility of repurposing produced water—an abundant byproduct of hydrocarbon extraction—for green hydrogen production in Wyoming USA. Analysis of geospatial distribution and production volumes reveals that there are over 1 billion barrels of produced water annually from key basins with a general total of dissolved solids (TDS) ranging from 35000 to 150000 ppm though Wyoming’s sources are often at the lower end of this spectrum. Optimal locations for hydrogen production hubs have been identified particularly in high-yield areas like the Powder River Basin where the top 2% of fields contribute over 80% of the state’s produced water. Detailed water-quality analysis indicates that virtually all of the examined sources exceed direct electrolyzer feed requirements (e.g. 10% LCOH) are notable electricity pricing (50–70% LCOH) and electrolyzer CAPEX (20–40% LCOH) are dominant cost factors. While leveraging produced water could reduce freshwater consumption and enhance hydrogen production sustainability further research is required to optimize treatment processes and assess economic viability under real-world conditions. This study emphasizes the need for integrated approaches combining water treatment renewable energy and policy incentives to advance a circular economy model for hydrogen production.

Considering economic and environmental aspects this study explored the potential of replacing urea imports in Jordan with local production utilizing green hydrogen considering agricultural land distribution fertilizer need and hydrogen demand. The analysis estimated the 2023 urea imports at approximately 13991.37 tons and evaluated the corresponding costs under various market scenarios. The cost of urea imports was projected to range between USD 6.30 million and USD 8.39 million; domestic production using green hydrogen would cost significantly more ranging from USD 30.37 million to USD 70.85 million. Despite the economic challenges transitioning to green hydrogen would achieve a 100% reduction in CO2 emissions eliminating 48739.87 tons of CO2 annually. Considering the Jordanian case an SWOT analysis was conducted to highlight the potential transition strengths such as environmental benefits and energy independence alongside weaknesses such as high initial costs and infrastructure gaps. A competitive analysis was conducted to determine the competition of green hydrogen-based ammonia compared to conventional methods. Further the analysis identified opportunities advancements in green hydrogen technology and potential policy support. Threats were assessed considering global competition and market dynamics.

The growing demand for clean energy and sustainable industrial processes has driven interest in integrated energy systems that optimize resource utilization while minimizing environmental impacts. This study presents the simulation and environmental sustainability assessment of an integrated process combining liquefied natural gas (LNG) Allam–Fetvedt cycle solid oxide electrolysis’ system and methanol synthesis to produce clean energy. The proposed system enhances overall efficiency and sustainability by utilizing the Allam–Fetvedt cycle to generate power while capturing CO2 which is then used in the manufacture of syngas and hydrogen by the electrolysis of water and CO2. Syngas is subsequently transformed into methanol a viable alternative fuel characterized by lowcarbon emissions. A comprehensive process simulation is conducted to evaluate energy efficiency material flows and system performance. The sustainability assessment focuses on environmental impact indicators including carbon footprint reduction energy efficiency improvements and resource optimization. The results demonstrate that the integrated system significantly reduces CO2 emissions while maximizing energy recovery making it a promising approach for decarbonized energy production. In this study the integrated process including the ASU power cycle electrolyzers methanol production units and LNG unit results in carbon emissions of 0.29 kg CO2 per kg of LNG produced which is very close to the literature-reported lower limit even though it also has methanol production. On the other hand when the identical process is assessed solely for methanol production (without the LNG unit) it attains net-zero carbon emissions. Despite the incorporation of high-energy electrolyzer systems the overall energy demand of the proposed integrated process remains comparable to that of existing conventional technologies with high emission outputs.

This study explores the integration and optimization of a hydrogen-based energy system emphasizing the use of metal hydride (MH) storage coupled with Proton Exchange Membrane Fuel Cell Micro Combined Heat and Power (PEMFC MCHP) system for residential applications. MH storage coupled to a heat pump operates at charging and discharging pressures of 10 bar. COMSOL model in 6.1 version using heat transfer in solids and fluids in brinkman equations modules is validated by experimental data and uses machine learning (Feedforward Neural Networks) for predictive modeling of MH dynamics. Smaller 500 NL tanks were found to have high mass-specific heat demand but faster hydrogen gas kinetics reaching (~77 % capacity in one hour) whereas larger 6500 NL (~57 %/hour) absorb hydrogen gas more gradually but reduce thermal management intensities. Using 13 × 500 NL tanks reach ~25 % discharge in 1 h but require ~2170 Wh heating whereas one 6500 NL tank only attains ~48.5 % discharge yet uses ~1750 Wh illustrating a trade-off between faster kinetics and lower thermal load. A genetic algorithm identified an optimal configuration of two 6500 NL tanks that covered ~68 % of total hydrogen gas consumption and 65 % of production at a maximum of 2.4 kW heating and 2.45 kW cooling. Additional comparisons with 170 bar compressed storage revealed lower instantaneous thermal requirements for high-pressure gas tanks. Adding a 170 bar compressed H2 alongside the 10 bar MH system hydrogen gas coverage rose from ~70 % to ~97 % when storage expanded to 200 Nm3 but at the cost of higher compression energy. The proposed MH-based approach especially at moderate pressures with carefully planned tank geometries achieves enhanced operational flexibility for a residential 120 m2 building’s space heating and hot water while machine learning optimizations further refine charge–discharge performance.