Hydrogen Production Technologies Research Articles

Research Progress on Characteristics of On‐Line Hydrogen Production by Methanol Steam Reforming

On‐line hydrogen production via methanol steam reforming (MSR) has gained considerable interest due to its high efficiency, affordability, and eco‐friendliness. Currently, this technology has been widely applied in the industry and has become an important method for hydrogen energy production. However, there are still some issues with this technology, such as short catalyst lifespan and CO pollution, which require further research and improvement. This article provides a comprehensive review of the research progress made in this field, with a particular focus on the catalyst development, reaction mechanism, theoretical calculation, and reactor design. Additionally, the challenges and prospects of on‐line hydrogen production by MSR are also discussed. In conclusion, MSR technology for hydrogen production has vast application prospects and development potential. It will be further explored in‐depth and extensively in future research.

Mo-Induced Surface Reconstruction in Ni/Co-OOH Prickly Flower Clusters for Improving the Hydrogen Production in Alkaline Seawater Splitting.

Seawater electrolysis is the most promising technology for hydrogen production, in which surface reconstruction on the interface of electrode/electrolyte plays a crucial role in activating the catalytic reactions with a low activation energy barrier. Herein, an efficient Mo modifying NiCoMo prickly flower clusters electrocatalyst supported on nickel foam (Mo-doped Ni/Co-OOH prickly flower clusters) is obtained, which serves as an eminently active and durable catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) due to the surface reconstruction during the alkaline seawater electrolysis with ultralow overpotentials. It just requires a cell voltage of 1.52V to achieve the current density of 10mAcm-2 for water electrolysis along with robust durability over 30h. Mo doping effectively regulates the surface reconstruction of Ni/Co-OOH, which facilitates the adsorption of oxygen-containing intermediates on the active center, and the nonhomogeneous interface induces charge rearrangement for the catalytic process to improve efficiency, providing a new strategy for revealing the seawater electrolytic mechanism.

Coordinated planning model for multi-regional ammonia industries leveraging hydrogen supply chain and power grid integration: A case study of Shandong

With the advancement of green hydrogen production technology, power-to-ammonia (P2A) has emerged as a pivotal approach for consuming large-scale renewable resources. However, the inherent intermittency of wind and solar resources leads to a spatial and temporal mismatch between supply and demand, rendering effective integration within a single region challenging and necessitating cross-regional collaborative planning. To address this, we propose a coordinated planning model for a multi-regional ammonia industrial system (MAIS) that leverages the integration of a hydrogen supply chain (HSC) and power grid (PG), termed HSC-PG-MAIS. During the modeling of the HSC, we developed a novel hydrogen truck transportation model that allows trucks to serve as both hydrogen storage and transportation resources. Furthermore, considering the cooperative relationships among ammonia industrial systems in different regions, we proposed a Nash bargaining method based on the magnitude of interactive value contributions to equitably allocate the cooperation costs and benefits of the MAIS. Finally, real data from Shandong Province in China is used to validate the effectiveness and significance of the proposed model and strategy. The results indicate that the proposed model can effectively reduce the overall operating costs of the system and enhance its flexibility, providing valuable insights into exploring the collaborative potential of large-scale renewable resources across regions.

Optimal Scheduling Strategy for Urban Distribution Grid Resilience Enhancement Considering Renewable-to-Ammonia Coordination

The integration of numerous distributed energy sources into the power system offers exciting opportunities to enhance the resilience of distribution networks. It is worth noting that the renewable-to-ammonia system has the potential to alleviate the multi-temporal and spatial imbalance of the power system. Therefore, this paper proposes a mathematical model for a renewable-to-ammonia system, taking into account the material balance and power balance of each unit. Based on this, this paper further explores the optimization scheduling method for flexible ammonia loads in distribution networks. A relaxation method for branch flow models in distribution networks based on second-order cone programming is proposed. An optimization scheduling model for flexible ammonia loads in distribution networks is constructed to minimize network loss. Moreover, considering the environmental advantages of the renewable-to-ammonia system, this paper compares the changes in hydrogen production technologies under different carbon emission constraints. Finally, a case study of the IEEE 33-node system is adopted to verify the effectiveness of the proposed model and method. It indicates that the renewable-to-ammonia system has environmental benefits and can reduce network loss to a certain extent.

Navigating Alkaline Hydrogen Evolution Reaction Descriptors for Electrocatalyst Design

The quest for efficient green hydrogen production through Alkaline Water Electrolysis (AWE) is a critical aspect of the clean energy transition. The hydrogen evolution reaction (HER) in alkaline media is central to this process, with the performance of electrocatalysts being a determining factor for overall efficiency. Theoretical studies using energy-based descriptors are essential for designing high-performance alkaline HER electrocatalysts. This review summarizes various descriptors, including water adsorption energy, water dissociation barrier, and Gibbs free energy changes of hydrogen and hydroxyl adsorption. Examples of how to apply these descriptors to identify the active site of materials and better design high-performance alkaline HER electrocatalysts are provided, highlighting the previously underappreciated role of hydroxyl adsorption-free energy changes. As research progresses, integrating these descriptors with experimental data will be paramount in advancing AWE technology for sustainable hydrogen production.

Bridging Quantum Mechanics and Hydrogen Technology: The MEQ Framework

The quest for sustainable and renewable energy sources has become a paramount objective in the contemporary scientific and technological landscape. Amidst various alternatives, hydrogen emerges as a promising candidate, offering a clean, efficient, and versatile fuel option. However, the efficient and cost-effective production of hydrogen, particularly through water splitting, presents significant scientific and engineering challenges. This article delves into the innovative convergence of theoretical physics and practical engineering through the lens of the McGinty Equation (MEQ). The MEQ framework, a novel integration of quantum field theory and fractal potentials, proposes groundbreaking approaches to optimize the water-splitting process at the atomic and molecular levels. This exploration is not merely an academic exercise but a step towards tangible solutions in the pursuit of sustainable energy, with the MEQ playing a pivotal role in enhancing hydrogen production technologies.

Technology for Green Hydrogen Production: Desk Analysis

The use of green hydrogen as a high-energy fuel of the future may be an opportunity to balance the unstable energy system, which still relies on renewable energy sources. This work is a comprehensive review of recent advancements in green hydrogen production. This review outlines the current energy consumption trends. It presents the tasks and challenges of the hydrogen economy towards green hydrogen, including production, purification, transportation, storage, and conversion into electricity. This work presents the main types of water electrolyzers: alkaline electrolyzers, proton exchange membrane electrolyzers, solid oxide electrolyzers, and anion exchange membrane electrolyzers. Despite the higher production costs of green hydrogen compared to grey hydrogen, this review suggests that as renewable energy technologies become cheaper and more efficient, the cost of green hydrogen is expected to decrease. The review highlights the need for cost-effective and efficient electrode materials for large-scale applications. It concludes by comparing the operating parameters and cost considerations of the different electrolyzer technologies. It sets targets for 2050 to improve the efficiency, durability, and scalability of electrolyzers. The review underscores the importance of ongoing research and development to address the limitations of current electrolyzer technology and to make green hydrogen production more competitive with fossil fuels.

Hydrogen production with a novel coaxial cylindrical electrolyser: A CFD study

This study introduces a unique coaxial cylindrical electrode design for Alkaline Water Electrolysers (AWEs) that is analyzed to show possible enhancements over the traditional stacked plate design. It investigates the performance of the proposed coaxial AWE for enhanced hydrogen production. Through comprehensive computational simulations, key performance indicators, such as current density and hydrogen volume fraction, are analyzed across various operating parameters. The results of this study indicate that the production rate of hydrogen achieves its highest level at a volume percentage of 3.4 %. This rate is significantly influenced by the concentration of the electrolyte, the distance between the cathode and anode rings, and, to a lesser degree, the porosity of the separator. Consequently, the optimized conditions demonstrate a promising increase in current densities, reaching 1000 mA/cm2 at an operating voltage of 2 V, showcasing the potential for developing more efficient and cost-effective AWE systems. This study further contributes valuable insights into the design and operational improvements needed for the advancement of large-scale hydrogen production technologies.

In-situ construction of N doped Zn0.6Cd0.4S/oxygen vacancy-rich WO3 Z-scheme heterojunction compound for boosting photocatalytic hydrogen production

Photocatalytic water splitting technology for hydrogen(H2) production represents a promising and sustainable approach to clean energy generation. In this study, a high concentration of oxygen vacancies was introduced into tungsten trioxide (WO3) to create a vacancy-rich layer. This modified WO3 was then combined with N-doped Zn0.6Cd0.4S through a hydrothermal synthesis, resulting in the formation of a Z-scheme heterojunction composite material aimed at enhancing photocatalytic performance. Under visible light, the H2 production rate of the composite reached an impressive 8.52 mmol·g−1 without adding co-catalyst platinum (Pt). This corresponds to enhancements of 7.82 and 4.39 times the production yield of pure ZCS and ZCSN, respectively. However, the hydrogen production increased to 21.98 mmol·g−1 when Pt was incorporated as a co-catalyst. Furthermore, an array of characterizations were employed to elucidate the presence of oxygen vacancies and the establishment of the Z-scheme heterojunction. This structural enhancement significantly facilitates the utilization of photo-generated electrons while effectively preventing photo-corrosion of ZCSN, thus improving material stability. Our study provides a new scheme for the incorporation of oxygen-rich vacancy and the construction of Z-scheme heterojunction, demonstrating a synergistic effect that greatly advances photocatalytic performance.

Graphitic carbon nitride nanosheets decorated with HAp@Bi2S3 core–shell nanorods: Dual S-scheme 1D/2D heterojunction for environmental and hydrogen production solutions

By combining different semiconductors, scientists have developed innovative materials capable of converting solar energy into useful forms of energy or driving chemical reactions that clean up pollutants. These materials offer a promising path to combat global environmental and energy challenges. In this study, HAp@Bi2S3 core–shell structures were synthesized using a facile microemulsion technique, and then loaded onto graphitic carbon nitride via a hydrothermal method to create an advanced HAp@Bi2S3/g-C3N4 dual S-scheme heterojunction. The engineered heterojunction exhibited enhanced hydrogen production and visible light photocatalytic oxidation of metronidazole. The improved photocatalytic efficiency was attributed to the core–shell structure of HAp@Bi2S3 along with the formation of a dual S-scheme heterojunction in HAp@Bi2S3/g-C3N4. As a result, the novel dual S-scheme HAp@Bi2S3/g-C3N4 heterojunction demonstrated a significantly higher hydrogen production rate, ca. 20 times higher than that of hydroxyapatite (HAp), 11 times higher than Bi2S3, and 5 times higher than the HAp@Bi2S3. This research introduces a novel approach to crafting dual S-scheme heterojunctions based on Bi2S3, which enables swift electron transfer across heterojunction interfaces, thereby enlarged possibility windows to sustainable hydrogen production and wastewater remediation technologies.

Optimization of a Novel Hydrogen Production Process Integrating Biomass and Sorption-Enhanced Reforming for Reduced CO2 Emissions

Recently, there has been a growing demand for clean and sustainable energy sources to bridge the energy gap. Hydrogen has emerged as an attractive and environmentally friendly energy carrier due to its potential for high energy efficiency and minimal pollution generation, making it a promising alternative to fossil fuels. This study proposes and investigates a novel coupled process that utilizes chemical looping technologies for hydrogen production, simultaneously utilizing natural gas and biomass as feedstocks. The primary objective of this research is to develop a process model that maximizes hydrogen production while minimizing carbon dioxide emissions. Aspen Plus version 10 was employed to simulate and analyze the proposed process configuration to achieve this. One of the proposed process's key advantages is its competitiveness compared to conventional steam methane reforming (SMR) processes, which are widely used in industry. The novel process offers significant benefits, such as enhanced hydrogen purity and reduced CO2 content in the product gas. The simulation results obtained from Aspen Plus reveal the successful production of highly pure hydrogen with a molar ratio of H2/CO equal to 268 and syngas with a molar ratio of H2/CO approximately equal to 1. Additionally, the process demonstrates the capability to produce highly high-purity hydrogen with a molar ratio of H2/CO equal to 155,000 in three-section reactors.

Effect of electron redistribution on H adsorption and hydrogen production efficiency

Water electrolysis is a promising, carbonless technology for hydrogen production, however, its widely industrial application is severely limited by the extensive energy consumption caused by sluggish oxygen evolution reaction (OER) kinetics. Herein, the simple Mn doping is employed to finely tune sulfur vacancies (VS). The thoeretic calculations prove that the electron structure has been well controlled. Compared with perfect MoS2 (without VS), the electron re-distribution of Mn-doped MoS2 with VS (Vs-Mn-MoS2) exhibits the both modes: electron depletion near the VS and electron accumulation between two Mo atoms. Furthermore, the well-controlled electron structure obviously promotes H adsorption. The experimental results shows that the 5 wt% Mn–MoS2 exhibits an excellent hydrogen evolution reaction (HER) activity (79 mV/10 mA cm−2, 55.46 mV dec−1), which is better than the other MoS2-based electrolysts in the previous reports. Moreover, an innovative substitution anode reaction is designed, namely, glycerol oxidation reaction (GOR)-based symmetric electrolyser with Mn–MoS2 as the both electrodes. At 60 mA cm−2, the cell voltage of GOR-based electrolyser has decreased by 14.8 %, and its Faradaic efficiency for HER increases by 10.04 % compared to conventional water-based one. This result proves that about 14.8 % of electric energy can be economized. Thus, this innovative electrocatalysis system could be promising for industrial hydrogen production.

Integrating green hydrogen production with renewable energy-powered desalination: An analysis of CAPEX implications and operational strategies

The study examines how sustainable energy transitions can meet freshwater needs in green hydrogen production. It proposes four configurations that combine polymer electrolyte membrane (PEM) water electrolysis with renewable energy-powered desalination methods, capable of both continuous and intermittent operations. This study evaluates the capital expenditure (CAPEX) implications of integrating solar or wind energy with seawater reverse osmosis (SWRO) and multi-effect distillation (MED) desalination to produce green hydrogen. It examines the capacities of renewable energy sources, the effectiveness of energy storage solutions, and the performance of various desalination methods, particularly their combined impact on economic viability and overall project costs. An SWRO system intermittently powered by wind energy is identified as the most cost-effective, reducing CAPEX by 46%. The results emphasize the practical benefits of integrating green desalination with green hydrogen production technologies.

Exergy analysis in intensification of sorption-enhanced steam methane reforming for clean hydrogen production: Comparative study and efficiency optimisation

Hydrogen has a key role to play in decarbonising industry and other sectors of society. It is important to develop low-carbon hydrogen production technologies that are cost-effective and energy-efficient. Sorption-enhanced steam methane reforming (SE-SMR) is a developing low-carbon (blue) hydrogen production process, which enables combined hydrogen production and carbon capture. Despite a number of key benefits, the process is yet to be fully realised in terms of efficiency. In this work, a sorption-enhanced steam methane reforming process has been intensified via exergy analysis. Assessing the exergy efficiency of these processes is key to ensuring the effective deployment of low-carbon hydrogen production technologies. An exergy analysis was performed on an SE-SMR process and was then subsequently used to incorporate process improvements, developing a process that has, theoretically, an extremely high CO2 capture rate of nearly 100 %, whilst simultaneously demonstrating a high exergy efficiency (77.58 %), showcasing the potential of blue hydrogen as an effective tool to ensure decarbonisation, in an energy-efficient manner.

Life Cycle Assessment of CO2-Based and Conventional Methanol Production Pathways in Thailand

Methanol production through carbon capture and utilization technologies offers promising alternatives to traditional natural-gas-based methods, potentially mitigating climate change impacts and improving resource efficiency. This study evaluates four methanol production pathways: CO2 hydrogenation, tri-reforming of methane, electrochemical CO2 reduction, and co-electrolysis of CO2 and water. The analysis covers 19 scenarios, combining three electricity mixes (100% Thai grid mix, 50% Thai grid mix and 50% renewable energy, and 100% renewable energy) with two hydrogen production technologies (alkaline water electrolysis and grey hydrogen). Environmental life cycle assessment results showed that most pathways perform well when using the 100% renewable energy with co-electrolysis (CE-100%) showing the most substantial reductions across all impact categories as compared conventional methanol production. Electrochemical reduction demonstrated the poorest environmental performance for all scenarios. In Thailand, implementing the CE-100% pathway could potentially yield 12.4 million tonnes of methanol annually from the cement industry’s CO2 emissions, with an estimated value of approximately USD 5.4 billion, while reducing emissions from the industrial processes and product use (IPPU) sector by 75%. The findings provide valuable insights for policymakers, industry stakeholders, and researchers, supporting Thailand’s transition towards sustainable methanol production and broader climate goals.

Underlying Developments in Hydrogen Production Technologies: Economic Aspects and Existent Challenges

Underlying Developments in Hydrogen Production Technologies: Economic Aspects and Existent Challenges

Highly efficient p-p heterojunction Co3S4/NiS2 electrocatalyst for water splitting and electrochemical oxidation of organic molecules

Organic small molecular-assisted water splitting technology is an efficient and promising technology for hydrogen production, which can meet the needs of obtaining hydrogen energy and protecting the environment. Constructing heterojunctions to enhance the interfacial electron transfer and achieve bifunctionality represents a viable strategy for enhancing the performance of electrocatalysts. In this work, the hollow structure Co3S4/NiS2 p-p heterojunction catalyst has been successfully synthesized by one-step hydrothermal method. Only −0.184, 1.64, 1.44 and 1.56 V vs. RHE are required to drive 50 mA cm−2 for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), urea oxidation reaction (UOR), oxygen evolution reaction in lactic acid solution (OER-LA), respectively. For two-electrode electrolytic process, the cell voltages only need 1.72 V, 1.51 V and 1.61 V to drive 50 mA cm−2 in 1 M KOH, 1 M KOH containing 0.5 M urea and 1 M KOH containing 0.5 M lactic acid electrolytes, and it operates continuously at 50 mA cm−2 for 200 h test without significant decay of activity in 1 M KOH containing 0.5 M lactic acid, showing excellent durability. Density functional theory (DFT) calculation reveals that the p-p heterojunction between Co3S4 and NiS2 facilitates the electron redistribution at interfaces, thereby promoting the electron migration. This work presents a strategic approach for fabricating advanced bifunctional electrocatalysts by employing metal sulfides to form heterojunction, thereby achieving enhanced electrocatalytic activities in both hydrogen production and organic molecule decontamination.

Terbium- and samarium-doped Li2ZrO3 perovskite materials as efficient and stable electrocatalysts for alkaline hydrogen evolution reactions.

The preparation of highly active, rare earth, non-platinum-based catalysts for hydrogen evolution reactions (HER) in alkaline solutions would be useful in realizing green hydrogen production technology. Perovskite oxides are generally regarded as low-active HER catalysts, owing to their unsuitable hydrogen adsorption and water dissociation. In this article, we report on the synthesis of Li2ZrO3 perovskites substituted with samarium and terbium cations at A-sites for the HER. LSmZrO3 (LSmZO) and LTbZrO3 (LTbZO) perovskite oxides are more affordable materials, starting materials in abundance, environmentally friendly due to reduced usage of precious metal and moreover have potential for several sustainable synthesis methods compared to commercial Pt/C. The surface and elemental composition of the prepared materials have been confirmed by X-ray photoelectron spectroscopy (XPS). The morphology and composition analyses of the LSmZO and LTbZO catalysts showed spherical and regular particles, respectively. The electrochemical measurements were used to study the catalytic performance of the prepared catalyst for hydrogen evolution reactions in an alkaline solution. LTbZO generated 2.52mmol/g/h hydrogen, whereas LSmZO produced 3.34mmol/g/h hydrogen using chronoamperometry. This was supported by the fact that the HER electrocatalysts exhibited a Tafel slope of less than 120mV/dec in a 1.0M alkaline solution. A current density of 10mA/cm2 is achieved at a potential of less than 505mV. The hydrogen production rate of LTbZO was only 58.55%, whereas LSmZO had a higher Faradaic efficiency of 97.65%. The EIS results demonstrated that HER was highly beneficial to both electrocatalysts due to the relatively small charge transfer resistance and higher capacitance values.

Degradation behavior of galvanostatic and galvanodynamic cells for hydrogen production from high temperature electrolysis of water

High temperature electrolysis of water using solid oxide electrochemical cells (SOEC) is a promising technology for hydrogen production with high energy efficiency and may promote decarbonization when coupled with renewable energy sources and excess heat from nuclear reactors. Apart from the technoeconomic considerations, commercial deployment of this technology critically depends on the long-term performance and durability of SOEC cells/stacks, especially under dynamic operations to withstand the intermittency of renewable energy. Herein, SOEC operation was conducted under galvanodynamic conditions and compared with galvanostatic cells to examine the effect on degradation behavior at an average current density of −0.75 A cm−2 at 750 °C. While dynamic operation shows no significant impact on the overall degradation rates compared to constant current operation, minor performance improvement was observed at potentials above 1.5 V when switched to galvanodynamic mode. The relatively lower overpotential during dynamic operation could not be explained by the negligible changes in the electrochemical impedance or cell temperature. Multiphysics modeling reveals that the oxygen partial pressure (PO2) in the electrolyte oscillates with the alternating current density under dynamic operations. The minor improvement in cell performance under dynamic mode might be associated with the relatively lower PO2 buildup as compared with that under galvanostatic operation. In addition, dynamic operation at high frequencies could effectively lower the extreme PO2 in the electrolyte, thus relieving stresses in the cells and alleviating cell degradation.

Regulating Strain and Electronic Structure of Indium Tin Oxide Supported IrOx Electrocatalysts for Highly Efficient Oxygen Evolution Reaction in Acid.

The development of proton exchange membrane water electrolysis is a promising technology for hydrogen production, which has always been restricted by the slow kinetics of the oxygen evolution reaction (OER). Although IrOx is one of the benchmark acidic OER electrocatalysts, there are still challenges in designing highly active and stable Ir-based electrocatalysts for commercial application. Herein, a Ru-doped IrOx electrocatalyst with abundant twin boundaries (TB-Ru0.3Ir0.7Ox@ITO) is reported, employing indium tin oxide with high conductivity as the support material. Combing the TB-Ru0.3Ir0.7Ox nanoparticles with ITO support could expose more active sites and accelerate the electron transfer. The TB-Ru0.3Ir0.7Ox@ITO exhibits a low overpotential of 203 mV to achieve 10 mA cm-2 and a high mass activity of 854.45 A g-1noblemetal at 1.53 V vs RHE toward acidic OER, which exceeds most reported Ir-based OER catalysts. Moreover, improved long-term stability could be obtained, maintaining the reaction for over 110 h at 10 mA cm-2 with negligible deactivation. DFT calculations further reveal the activity enhancement mechanism, demonstrating the synergistic effects of Ru doping and strains on the optimization of the d-band center (εd) position and the adsorption free energy of oxygen intermediates. This work provides ideas to realize the trade-off between high catalytic activity and good stability for acidic OER electrocatalysts.