Hydrogen Production Technologies Research Articles

When less is more: Enhancement of green hydrogen production and efficiency by using electrodes with ultra-low platinum loadings

Sulfur dioxide depolarized electrolysis (SDE) is a promising technology for cost-effective green hydrogen production that can be used for the storage of intermittent renewable energies used to power the electrolyzer. The obtained hydrogen can be stored and used as a source for producing electricity in a fuel cell. However, high platinum loadings (around 2 mgPt cm−2) in the anode and cathode electrodes significantly contribute to the overall cost of the electrolyzer. This study aimed to optimize both electrodes using the electrospray technique for the deposition of ultra-low Pt loadings. The electrodes achieved a total platinum loading as low as 0.4 mgPt cm−2 (0.3 mgPt cm−2 for the anode and 0.1 mgPt cm−2 for the cathode), an 80 % reduction compared to common platinum loadings. This reduction not only increased the hydrogen production rate (18 mL min−1 with optimized electrodes vs. 4.7 mL min−1 with non-optimized electrodes) but also decreased the production of hydrogen sulfide in the cathode, resulting in a hydrogen stream with higher purity. Overall, this study demonstrates the potential of electrospray for achieving low platinum loadings and improving the efficiency of SDE for green hydrogen production.

Energy, techno-economic analysis, and life cycle assessment for co-gasification of polyethylene terephthalate and olive husk by chemical process simulation

Waste-to-energy is emerging as a promising technology that can reduce greenhouse gas emissions and solve waste disposal problems. This study focused on hydrogen production technology through waste gasification. Polyethylene terephthalate (PET), which has a high calorific value was selected as a waste fuel, and biomass of olive husk, which can reduce the problems of gasification for PET, was selected as an additional fuel. In this study, hydrogen production research was conducted through mixed gasification of plastic and biomass, and process simulation was performed using Aspen Plus. Gasifier temperature and steam/fuel ratio were set as major variables to confirm their influences on the co-gasification reaction, and the production of H2, CH4, CO, and CO2, which are the main products of the gasification reaction, was analyzed. In addition, the techno-economic analysis and life cycle assessment were conducted. Based on the analysis results, optimal conditions for hydrogen production were discussed.

Tailored Two‐Dimensional Transition Metal Dichalcogenides for Water Electrolysis: Doping, Defect, Phase, and Heterostructure

AbstractThe demand for hydrogen production technology to replace fossil fuels and address the global climate crisis has become one of the most urgent tasks in the modern era. Among the promising breakthroughs, electrochemical water splitting using renewable energy sources offers a path to green hydrogen production that is both feasible and economically viable. However, the current state‐of‐the‐art catalysts for the water‐splitting reaction predominantly rely on scarce and costly noble metals, posing a significant challenge to the mass production of green hydrogen. In this context, two‐dimensional transition metal dichalcogenides (2D TMDs) have emerged as compelling candidates to replace noble metals, owing to their impressive reactivity and cost‐effectiveness. These TMD‐based electrocatalysts demonstrate exceptional reactivity at their active edge sites, while the basal planes remain catalytically inert. Several tailored strategies can activate these basal planes by modifying the chemical bonding nature and electronic band structure of the constituent atoms, thus enhancing the overall reactivity of TMDs. This review summarizes recent advancements in the modulation methodologies of 2D TMDs to enhance their water‐splitting reactivity. We highlight various chemical modification strategies, including heteroatom doping, defect‐engineering, and heterostructure formation, and provide insights into future research directions for the development of advanced 2D TMD‐based water‐splitting catalysts.

Optimizing large-scale hydrogen storage: A novel hybrid genetic algorithm approach for efficient pipeline network design

As hydrogen production technologies continue to advance, efficient and high-capacity hydrogen storage solutions become increasingly crucial. To address the complex optimization challenges in the design of large-scale hydrogen storage pipeline networks, the study introduces a mixed integer nonlinear optimization model inspired by hydrogen pipeline design optimization theory. The model not only focuses on optimizing network design parameters but also aims to minimize investment costs. To achieve this, the study proposes an innovative hybrid genetic algorithm that combines the Modified Feasible Directions Method (MFDM) and Genetic Algorithm Theory (GAT), specifically targeting the optimization of pipeline diameter's discrete distribution challenges. Comparative analyses with SUMT and GA algorithms demonstrate the superiority of the approach. In continuous space, the algorithm achieves a lower convergence cost of 232.4437 × 104 Yuan, while in discrete space, the cost further decreases to 212.1636 × 104 Yuan. Additionally, the study delves into the sensitivity of the HGA-MFDM algorithm to ambient temperature and wellhead temperature in hydrogen storage facilities. The analysis reveals that wellhead temperature has a more significant impact on pipeline network investment, whereas ambient temperature exhibits a more pronounced effect on iteration curves. The findings provide valuable insights for the precise adjustment and optimization of hydrogen storage pipeline networks in practical applications.

Rationally designing of Co-WS2 catalysts with optimized electronic structure to enhance hydrogen evolution reaction

Designing and developing cost-effective, high-performance catalysts for hydrogen evolution reaction (HER) is crucial for advancing hydrogen production technology. Tungsten-based sulfides (WSx) exhibit great potential as efficient HER catalysts, however, the activity is limited by the larger energy required for water dissociation under alkaline conditions. Herein, we adopt a top-down strategy to construct heterostructure Co-WS2 nanofiber catalysts. The experimental results and theoretical simulations unveil that the work functions-induced built-in electric field at the interface of Co-WS2 catalysts facilitates the electron transfer from Co to WS2, significantly reducing water dissociation energy and optimizing the Gibbs free energy of the entire reaction step for HER. Besides, the self-supported catalysts of Co-WS2 nanoparticles confining 1D nanofibers exhibit an increased number of active sites. As expected, the heterostructure Co-WS2 catalysts exhibit remarkable HER activity with an overpotential of 113 mV to reach 10 mA cm−2 and stability with 30 h catalyzing at 23 mA cm−2. This work can provide an avenue for designing highly efficient catalysts applicable to the field of energy storage and conversion.

Investment risk assessment of anaerobic fermentation based hydrogen production project based on regret linguistic Z-number averaging Choquet integral operator

Anaerobic fermentation based hydrogen production technology has a good market investment prospect for its advantages of abundant raw material sources, low cost and low energy consumption. The industry is in the early stage of development and will face many risks. The corresponding risk assessment has not yet attracted attention. Therefore, this paper constructs a risk assessment framework. Firstly, 17 critical risk factors affecting the anaerobic fermentation based hydrogen production project is identified and grouped into five categories. The linguistic Z-number is then used to describe the uncertainty. Later, a regret linguistic Z-number averaging Choquet integral operator is put forward to deal with interrelationships between criteria and simulate the decision-makers’ regret avoidance attitudes. In addition, a novel relative entropy measure is determined, wherein the expert weight model is established by combining the reliability measure. Subsequently, a case study is conducted and the result demonstrates the risk level of the project located in Hubei, China is between “Medium” and “Slightly high”. Finally, some measures are proposed to deal with these risks. This work can provide a theoretical basis for the risk prevention and investment decision of anaerobic fermentation based hydrogen production projects.

Numerical assessment and optimization of photovoltaic-based hydrogen-oxygen Co-production energy system: A machine learning and multi-objective strategy

Green hydrogen production technology based on photovoltaic (PV), battery energy storage system (BESS) and proton exchange membrane (PEM) water electrolysis plays a crucial part in the transition process of energy to zero carbon technology. But few studies have focused on achieving all-day continuous hydrogen production, which is the key to large-scale hydrogen utilization. In this study, we developed an off-grid PV-BESS-PEM system for hydrogen and oxygen production. Firstly, the PV, BESS and PEM water electrolysis components were modeled and model validation was performed. Secondly, an energy management strategy (EMS) is proposed to achieve the goal of continuous and stable hydrogen production. Then, a surrogate model between design variables and optimization objectives is established based on machine learning methods, and a multi-objective optimization algorithm is used to drive the optimization process. Finally, a case study of the PV-BESS-PEM system is presented based on solar irradiation data in Lhasa, where there is sufficient solar resources and oxygen demand. The results demonstrate that the EMS can satisfy the purpose of all-day continuous and stable hydrogen production. The number of cells in the electrolyzer and the water temperature have a significant effect on the hydrogen production and the electrolysis efficiency. And the optimal system has increased the hydrogen production by 16.80 % and the electrolysis efficiency of PEM by 12.08 %, respectively. Herein, the methodological framework is expected to provide theoretical guidance for large-scale water electrolysis hydrogen production applications based on solar energy.

Stainless steel as gas evolving electrodes in water electrolysis: Boosting the electrocatalytic hydrogen evolution reaction on electrodeposited Ni@CoP modified stainless steel electrodes

High efficient and durable electrocatalytic electrodes play a vital role in energy conversion and storage. In this concern, water electrolysis technology needs high performance electrodes with high activity and stability to implement this technology for green hydrogen production. Here, this study reports on the development of self-supported electrodes for the hydrogen evolution reaction (HER) based on sequential electrodeposition technique. First, the CoP has been deposited on stainless steel mesh (SSM) electrode followed by deposition of Ni to form Ni@CoP electrocatalysts standing on SSM. The loading amount of Ni was studied to achieve a high catalytic activity. The developed electrodes have been investigated with FE-SEM, EDX, XRD and XPS to identify their morphological properties as well as their chemical states and compositions. Electrocatalytic activity and durability have been studied in alkaline media by different electrochemical methods, such as LSV, EIS and CP. The results showed that the optimum deposition time of 10 min (10Ni@CoP) exhibited the higher catalytic activity in term of overpotential and Tafel slope giving a overpotential of 188 mV at 10 mA cm−2 with a small Tafel slope of 69 mV.dec−1 compared to CoP electrode with overpotential 266 mV and Tafel slope of 105 mV.dec−1 highlighting the role of Ni in enhancing the catalytic activity of the developed electrodes towards HER. Moreover, the Ni@CoP showed high stability under continues electrolysis at 50 and 100 mA.cm−2. These findings have been discussed in light of porous structure of the electrodes and introducing of Ni particles which led to creating more active sites and enhancing the hydrogen adsorption/desorption and thus facilitating the HER kinetics. The facial preparation method of self-supported electrodes and the obtained activity and stability of Ni@CoP electrodes render them as potent electrodes for HER in alkaline water electrolysis.

Self‐Powered System for H2 Production and Biomass Upgrading

AbstractHydrazine‐oxidation‐assisted self‐powered H2 generation system greatly expands the applicability of hydrogen production technology. However, the high cost of hydrazine greatly impedes the widespread adoption of hydrazine‐contained energy systems for large‐scale H2 production. Besides, the gaseous products of hydrazine splitting, comprising a mixture of H2 and N2, necessitate energy‐intensive downstream separation. Here, taking advantage of a low‐potential furfural oxidation reaction (FOR) on the Cu electrode, a self‐powered H2 production system by integrating a direct furfural fuel cell (DFFC) and a bipolar H2 production electrolyser is reported. Ru‐dispersed Cu nanowire with remarkable catalytic activity is developed as a hydrogen evolution reaction (HER) catalyst to couple with the FOR. The HER‐FOR electrolyzer achieves bipolar H2 production with an apparent 200% Faradaic efficiency, attaining a current density of 100 mA cm−2 with a low cell voltage of 0.43 V. The DFFC displays an open circuit potential of 0.969 V and a peak power density up to 193 mW cm−2. Inspired by the bipolar H2 production that eliminates the gas separation, a self‐powered system utilizing furfural as the sole consumable, which yields a pure H2 production rate of 6 mmol h−1 m−2 is demonstrated. This work provides a new avenue for constructing self‐powered H2 production systems.

Research Advances of Non-Noble Metal Catalysts for Oxygen Evolution Reaction in Acid.

Water splitting is an important way to obtain hydrogen applied in clean energy, which mainly consists of two half-reactions: hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, the kinetics of the OER of water splitting, which occurs at the anode, is slow and inefficient, especially in acid. Currently, the main OER catalysts are still based on noble metals, such as Ir and Ru, which are the main active components. Hence, the exploration of new OER catalysts with low cost, high activity, and stability has become a key issue in the research of electrolytic water hydrogen production technology. In this paper, the reaction mechanism of OER in acid was discussed and summarized, and the main methods to improve the activity and stability of non-noble metal OER catalysts were summarized and categorized. Finally, the future prospects of OER catalysts in acid were made to provide a little reference idea for the development of advanced OER catalysts in acid in the future.

Application Prospect of Carbon Dioxide Hydrogenation to Methanol Technology in the New Electric Power Systems

The new electric power systems based on new energy is a power system that is supported by source-grid-load-storage interaction and multi-energy complementarity, in order to reduce the carbon emission level of the new electric power systems, it is necessary to change the existing energy structure of the system through different energy carriers. Through technology comparison and analysis, seawater in-situ electrolysis hydrogen production technology can make full use of offshore renewable energy, which can effectively reduce the production cost of hydrogen production by electrolysis. With the development and industrial application of the third-generation low-energy phase change absorber, the technology of carbon dioxide capture by phase change solvent has great application prospects. The industrial application of carbon dioxide hydrogenation to methanol can rely on the existing mature C1 chemical system, and the new carbon dioxide hydrogenation to methanol device can improve the effective utilization rate of carbon dioxide and reduce the emission of tail gas. On this basis, the application scheme of carbon dioxide hydrogenation to methanol technology in the new power system is proposed: centered on the power grid, renewable energy is used to generate electricity, and part of the electricity is sent to the grid; part of the electricity is sent to the seawater in-situ electrolysis hydrogen production unit to produce hydrogen; the main product hydrogen is stored in the hydrogen storage equipment, and the by-product oxygen is used comprehensively; the carbon dioxide generated in the process of fossil fuel power generation is captured by phase change solvent, and then the new carbon dioxide hydrogenation to methanol device is used to synthesize carbon dioxide and hydrogen into methanol under the action of catalyst, part of the methanol is converted into hydrogen by cracking and stored, and the other part of methanol is directly used as the fuel of internal combustion power locomotives, when the power output of the grid is insufficient, methanol can be used as fuel for internal combustion generators, which are used to generate electricity and sent to the grid, and the stored hydrogen can also be used as fuel for hydrogen fuel cells, which are used to generate electricity and sent to the grid.

Sustainability of hydrogen production considering alternative technologies towards a neutral carbon society

Hydrogen can be produced from several feedstocks and technologies, making it an important partner in the energy transition to neutral carbon societies. Hydrogen production can be based on renewable feedstocks, such as agricultural residues, which are highly available and economical. However, a comprehensive analysis of all available hydrogen production technologies must be done. Therefore, this work focused on developing a comparative analysis of the sustainability of the main hydrogen production technologies. Technologies with the greatest opportunity for development were simulated and evaluated from a sustainability perspective. Techno-energetic, economic, environmental, and social indicators were used to calculate a comprehensive sustainability index (SId). Steam biomethane reforming (SBMR) and electrolysis (EL) were the schemes with the highest SId based on the techno-energetic and environmental dimensions. However, the SId decreased substantially when the economic dimension was considered because SBMR presented high capital and operating costs, and EL had low technical performance. On the other hand, thermochemical and biological technologies require further research to decrease the environmental burden and improve the mass yield of the process. Therefore, each production scheme involves different disadvantages that must be resolved to increase the opportunities for hydrogen development.

Self-standing Ni–Cu–Ti/NCNTs electrocatalyst with porous structure for hydrogen evolution reaction

The development of water electrolysis hydrogen production technology is of great significance for accelerating the global carbon neutrality goals. Nickel-based electrode materials are considered the most promising catalysts for alkaline water electrolysis. However, the slow kinetics of the hydrogen evolution reaction remains a key challenge to be solved. To address this, a porous Ni–Cu–Ti/NCNTs cathode electrode was prepared using the powder metallurgy method. The microstructure characterizations and electrochemical measurements revealed that adjusting the content of NCNTs, while maintaining the Ni–Cu–Ti ratio of 5.5:3.5:1, can improve the catalytic activity of hydrogen evolution to a certain extent. Among the electrodes tested at room temperature, the one with 0.7% NCNT content exhibited the best performance in terms of hydrogen evolution. The analysis suggests that the porous structure of the electrode provides ample channels for object transmission. The addition of NCNTs further enhances the surface roughness of the electrode, exposing more active sites. Additionally, NCNTs promote electron transfer, synergize with Ni, Cu, and Ti, and improve the catalytic activity of hydrogen evolution.

A high durable and conductive Mg(OH)2-filled PP/PE composite membrane for alkaline water electrolysis

Design and synthesis of a low-cost, high-durable, and conductive membrane are paramount in reducing energy losses for alkaline water electrolysis (AWE), which has emerged as a promising technology for green hydrogen production. In this study, we utilize Mg(OH)2 particles to fill the pores of a low-cost polypropylene/polyethylene (PP/PE) membrane, thereby reducing gas crossover and enhancing conductivity. This leads to the preparation of a Mg(OH)2-PP/PE composite membrane. When equipped in a flow-type AWE electrolyzer, this composite membrane exhibits a voltage of 1.93 V at a current density of 0.5 A cm−2 over a 100 h measurement period, which is superior to the commercial polyphenylene sulfide (PPS) membrane's voltage of 2.69 V. Furthermore, the 5000 h stability test, without any conductivity loss in the membrane, further confirms its high stability. The successful design of this composite membrane provides a new approach for high-performance AWE.

Molten salts coupled Ni/Al2O3 for hydrogen from CH4 pyrolysis at mild temperature in bubble-cap reactor

Methane pyrolysis is a promising sustainable technology for CO2-free hydrogen production. However, the development of stable methods for methane pyrolysis to produce hydrogen at lower temperatures has presented significant challenges. This study presents a reaction system that combines molten carbonate with Ni/Al2O3 catalyst and investigates methane pyrolysis using this system in a bubble-cap reactor. Remarkably, this system exhibited a low activation energy of 145.8 kJ per mole, enabling the achievement of a methane conversion of 92.5 % at 580 °C by employing a double-layer bubble cap tray configuration. Furthermore, the system showcases sustained activity for a duration of up to 72 h.

Thermodynamic Feasibility Evaluation of Alkaline Thermal Treatment Process for Hydrogen Production and Carbon Capture from Biomass by Process Modeling

Hydrogen is attracting attention as a low-carbon fuel. In particular, economical hydrogen production technologies without carbon emissions are gaining increasing attention. Recently, alkaline thermal treatment (ATT) has been proposed to reduce carbon emissions by capturing carbon in its solid phase during hydrogen production. By adding an alkali catalyst to the conventional thermochemical hydrogen production reaction, ATT enables carbon capture through the reaction of an alkali catalyst and carbon. In this study, a thermodynamic feasibility evaluation was carried out, and the effects of the process conditions for ATT with wheat straw grass (WSG) as biomass were investigated using Aspen Plus software V12.1. First, an ATT process model was developed, and basic thermodynamic equilibrium compositions were obtained in various conditions. Then, the effects of the process parameters of the reactor temperature and the mass ratio of NaOH/WSG (alkali/biomass, A/B value) were analyzed. Finally, the product gas compositions, process efficiency, and amount of carbon capture were evaluated. The results showed that the ATT process could be an efficient hydrogen production process with carbon capture, and the optimal process conditions were a reactor temperature of 800 °C, an A/B value of three, and a flow rate of steam of 6.9 × 10−5 L/min. Under these conditions, the maximum efficiency and the amount of carbon dioxide captured were 56.9% and 28.41 mmol/g WSG, respectively.

Macroporous NiFe-LDH accelerating highly-selective electrosynthesis of benzaldehyde accompanied with hydrogen production

Alkaline overall water splitting (OWS) is a potential technology for hydrogen (H2) production, however, the sluggish oxygen evolution reaction (OER) with high overpotential has limited its large-scale application. Herein, we successfully prepared the macroporous NiFe layered hydroxide (M-NiFe-LDH) on self-supported carbon cloth (CC) as electrocatalyst to drive an energy-saving device for both H2 production and benzyl alcohol (BA) oxidation to synthesize benzaldehyde (BAD). By utilizing the polystyrene (PS) microsphere templates and electrodeposition technology, CC@M-NiFe-LDH can be easily obtained after removing the PS templates. Due to the synergistic effect of bimetallic NiFe-LDH and macropores arrays which can expose more catalytic active sites, CC@M-NiFe-LDH electrocatalyst only needs a low potential of 1.31 VRHE to reach the current density of 10 mA cm−2 with a high BAD selectivity (∼99 %). Consequently, an energy-saving two-electrode device with both BAD electrosynthesis and H2 production can be assembled, which needs a low cell voltage of 1.648 V and electricity consumption of 3.60 kW h per cubic meter of H2, lower than that of OWS (1.826 V and 3.99 kW h).

Hydrogen Production from Rice Husk: Techno-Economic and Life Cycle Analysis

The abundance of rice husk in some regions of Southeast Asia makes it a potential feedstock for hydrogen synthesis. However, the information on economic and environmental feasibility of its conversion to hydrogen is lacking. This study aims to assess the techno-economic and life cycle sustainability of hydrogen production from rice husk via the thermochemical gasification method. The techno-economic analyses reveal that rice husk-based hydrogen conversion is more financially attractive than conventional hydrogen production technology. The results of the life cycle assessment are also promising, especially with the global warming potential of the rice husk-based hydrogen production being 99.7 % lower than that of natural gas steam reforming. Waste valorization of rice husk into hydrogen is therefore economically and environmentally viable.

Ag engineered NiFe-LDH/NiFe2O4 Mott-Schottky heterojunction electrocatalyst for highly efficient oxygen evolution and urea oxidation reactions

Efficient and durable electrocatalysts with sufficient active sites and high intrinsic activity are essential for advancing energy-saving hydrogen production technology. In this study, a Mott-Schottky heterojunction electrocatalyst with Ag nanoparticles in-situ grown on NiFe layered double hydroxides (NiFe-LDH)/NiFe2O4 nanosheets (Ag@NiFe-LDH/NiFe2O4) were designed and successfully synthesized through a hydrothermal process and subsequent spontaneous redox reaction. The in-situ growth of metallic Ag on semiconducting NiFe-LDH/NiFe2O4 triggers a strong electron interaction across the Mott-Schottky interface, leading to a significant increase in both the intrinsic catalytic activity and the electrochemical active surface area of the heterojunction electrocatalyst. As a result, the Ag@NiFe-LDH/NiFe2O4 demonstrates impressive oxygen evolution reaction (OER) performance in alkaline KOH solution, achieving a low overpotential of 249 mV at 100 mA cm−2 and a Tafel slope of 42.79 mV dec−1. When the self-supported Ag@NiFe-LDH/NiFe2O4 is coupled with the Pt/C electrocatalyst, the alkaline electrolyzer reaches a current density of 10 mA cm−2 at a cell voltage of only 1.460 V. Furthermore, X-ray photoelectron spectroscopy and in-situ Raman analysis reveal that the Ni(Fe)OOH is the possible active phase for OER in the catalyst. In addition, when employed for UOR catalysis, the Ag@NiFe-LDH/NiFe2O4 also displays intriguing activity with an ultralow potential of 1.389 V at 50 mA cm−2. This work may shed light on the rational design of multiple-phase heterogeneous electrocatalysts and demonstrate the significance of interface engineering in enhancing catalytic performance.

A brief review of hydrogen production technologies

As a result of the array of problems arising from the use of fossil fuels, it is necessary to develop and optimize alternative energy technologies. Despite hydrogen being an ideal form of energy, its primary source is still fossil fuels via conventional methods. Therefore, several hydrogen-production resources and techniques have been investigated, providing feasibility for clean and effective hydrogen production. This paper provided a mini-review of hydrogen production technologies, including renewable energy, chemical looping, water electrolysis, photocatalysis, and plasma.