Enhanced Hydrogen Production Research Articles

Enhanced Hydrogen Production in Microwave‐Driven Water‐Splitting Redox Cycles by Engineering Ceria Properties (Adv. Energy Mater. 38/2024)

Enhanced Hydrogen Production in Microwave‐Driven Water‐Splitting Redox Cycles by Engineering Ceria Properties (Adv. Energy Mater. 38/2024)

Nickel doped enhanced LaFeO3 catalytic cracking of tar for hydrogen production

The transformation of biomass into green energy was pivotal for sustainable development, yet the efficient conversion of biomass-derived tar into hydrogen-rich syngas remained a significant challenge. This study addressed the catalytic demand for hydrogen production from tar, focusing on the development of LaNixFe1-xO3 perovskites as catalysts. A series of LaNixFe1-xO3 perovskites with varying nickel doping levels (x=0, 0.25, 0.5, 0.75, 1) were synthesized to evaluate their catalytic performance in converting toluene, a representative tar component, into hydrogen. The LaNi0.5Fe0.5O3 catalyst demonstrated the highest hydrogen yield (14.5L/6h) and volume percentage (82.9V/V%), highlighting the optimal nickel doping level for enhancing hydrogen production. The hydrogen production performance of LaNixFe1-xO3 was significantly affected by nickel doping. In particular, a small amount of nickel doping can significantly enhance the hydrogen production capacity of LaFeO3 and maintain good reaction stability. The enhanced performance was attributed to the high oxygen storage capacity of perovskite, which facilitated the removal of surface carbon and promotes the methanation reaction. Notably, the total content of defect oxygen and surface adsorbed oxygen/hydroxyl groups significantly impacted the hydrogen production efficiency. These findings indicated that LaNi0.5Fe0.5O3 was an effective catalyst for converting biomass-derived tar into hydrogen-rich syngas, offering a promising solution to the catalytic demand in the hydrogen production system.

Enhance Hydrogen Production from Water Using 532 Lasers

ABSTRACT: hydrogen production via water electrolysis under the influence of laser sounds fascinating with its unique properties, was particularly effective in promoting hydrogen production. The mechanism by which the laser promotes hydrogen production The electrolytic cell used in this work contains 270 ml of distilled water stimulated with different amounts of alcohol (2 ml - 4 ml - 6 ml - 8 ml - 10 ml). This chamber consists of two vertically oriented cylinders. Inside each cylinder there are graphite electrodes, each measuring 10 x 5 x 7 mm3, connected to the positive and negative terminals of a direct current power source, in addition to using a green laser source (532). An efficiency study was conducted using a green laser with a wavelength of 532 nanometers as an optical light source for water analysis through electrolysis. Results were obtained using both the standard electrolysis method and with the green laser source (532 nm). In the case of standard electrolysis, we obtained (When adding 5 ml of cohol, we get 6.63 hydrogen ), while (Adding 10 ml of ill we get 7.44 of hydrogen ) was obtained when using the laser source. The results indicate that using the laser source enhances hydrogen production significantly compared to standard electrolysis, demonstrating the laser's high effectiveness in electrolysis due to its non-absorptive property in water. This could have significant implications for renewable energy and hydrogen fuel production.

Configuration optimization of a biomass chemical looping gasification (CLG) system combined with CO2 absorption

Biomass chemical looping gasification (CLG) combined with CO2 absorption in a dual circulating fluidized bed (DCFB) has emerged as an advanced technology for clean and efficient biomass utilization, yet the reactor design for achieving higher gasification performance and the in-depth understanding of physical-thermal-chemical characteristics is still lacking. This study presents an optimized design aimed at enhancing hydrogen production and carbon reduction in the biomass CLG process with a DCFB reactor by employing the multiphase particle-in-cell (MP-PIC) method integrated with thermochemical sub-models. The proposed reactor is comprehensively compared with the original reactor from the experimental setup in terms of particle mixing, heat transfer, and gasification behaviors. The results indicate that compared to the original setups, the proposed CLG system demonstrates: (i) an improved gas-solid mixing, as evidenced by the particle mixing index rising from 0.23 to 0.34; (ii) an enhanced particle heat transfer coefficient, which boosts heat and mass transfer process; (iii) a 10.11 % increase in H2 concentration alongside a 23.71 % decrease in CO2 concentration; (iv) a particle distribution characterized by higher concentration at the bottom and lower concentration at the top, along with intensified particle back-mixing. The pressure drop inside the combustor is higher than that in the gasifier. A smaller absorbent mean particle diameter and lower-positioned biomass feeding port contribute to the improvement of the CLG performance.

Porous and defective NiCo2O4 spinel derived from bimetallic NiCo-based Prussian blue analogue for enhanced hydrogen production via the urea electro-oxidation reaction

The efficient hydrogen production via overall water splitting is seriously restrained by the slow kinetics of the oxygen evolution reaction (OER). The substantially low potential for the urea electro-oxidation reaction (UOR) can tackle this problem by replacing the OER at the electrolyzer anode. Herein, the NiCo2O4 spinel with rich oxygen vacancies (Ov) and embedded within mesoporous carbon network (Ov-NiCo2O4@mC) was derived from NiCo-based Prussian blue analogous (NiCo PBA) and exploited as the bifunctional electrocatalyst of the UOR and OER for boost the hydrogen production via the overall water splitting. Benefiting to the regular skeleton and abundant dual metal sites of NiCo PBA, the derived Ov-NiCo2O4@mC comprises abundant oxygen vacancies, lattice defects, and adjustable electron structure. These features afford Ov-NiCo2O4@mC the improved UOR ability, showing the potential of 1.33 V versus reversible hydrogen electrode (RHE) at the current density of 10 mA cm−2, along with a small Tafel slopes of 31 mV dec−1, remarkably lower than that of the OER (1.51 V versus RHE, Tafel slope = 85 mV dec−1). The UOR performance of Ov-NiCo2O4@mC substantially outperforms to most of the reported Co and/or Ni-based electrocatalysts. Impressively, the assembled two-electrode urea-assisted overall water splitting device shows the small voltage for the hydrogen production (1.43 V versus RHE) and good long-term stability. The present work can provide a new alternative for the efficient hydrogen production using the MOFs-derivatives.

Organic municipal solid waste derived hydrogen production through supercritical water gasification process configured with K2CO3/SiO2: Performance study

Cities worldwide face a significant public health and environmental challenge in handling municipal solid waste (MSW). This research exposed an effective utilization of MSW as the source for hydrogen production via a supercritical water gasification process under 450–650 °C at 15–45 min processing time. The impacts of gasification temperature and processing time on the functional properties of hydrogen production are studied. Its results are compared to identify the optimum processing temperature and processing time to adopt the system. Integrating 3 wt% silicon dioxide (SiO2) nanoparticles/3 wt% of potassium carbonate (K2CO3) enhances hydrogen production by increasing the catalyst's surface area and improving the stability of active sites, leading to more efficient gasification reactions. Increasing the gasification temperature from 450 to 650 °C significantly raises the hydrogen molar fraction and gas yield with peak gasification efficiency (GE) and hydrogen efficiency (HE) values. The gasifier functioned with catalyst (3 wt% K2CO3/SiO2) under 650 °C gasification temperature and 45min gasification time influenced better output responses like improved hydrogen gas yield of 63.7 mol/kg, higher gasification efficiency of 59.8 %, better hydrogen efficiency (63.4 %) and increased carbon conversion efficiency of 63.4 and 42.5 % respectively.

Metal–organic framework derived RuNiMo/NC for enhanced hydrogen production and methanol reforming electrolysis

It is important to probe the effect of doping of ultratrace content of precious metal and synergistic effects of multimetals on effective electrocatalysts for water splitting. Thus, ultratrace content Ru doping NiMo-NC were acquired through simple hydrothermal technology and high-temperature pyrolysis. Benefiting from porous structure, ultratrace content Ru doping and synergistic effect of multiple metals, RuNiMo-NC-2 presents the small overpotentials of 130 and 199 mV for MOR to achieve 10 and 100mA cm−2 in 1 mol/L potassium hydroxide with 5 mol/L methanol. The assembled water electrolyzer with the RuNiMo-NC-2||RuNiMo-NC-2 couple only requires 1.49 V to realize 10mA cm−2 for the overall water splitting in 1 mol/L potassium hydroxide with 5 M methanol. This paper offers a feasible method for designing bifunctional electrocatalysts with superior electrocatalytic performance, which can be used in hydrogen production through water electrolysis.

Advances in the heterostructures for enhanced hydrogen production efficiency: a comprehensive review.

The growing global energy demand and heightened environmental consciousness have contributed to the increasing interest in green energy sources, including hydrogen production. However, the efficacy of this technology is contingent upon the efficient separation of charges, high absorption of sunlight, rapid charge transfer rate, abundant active sites and resistance to photodegradation. The utilization of photocatalytic heterostructures coupling two materials has proved to be effective in tackling the aforementioned challenges and delivering exceptional performance in the production of hydrogen. The present article provides a comprehensive overview of operational principles of photocatalysis and the combination of photocatalytic and piezo-catalytic applications with heterostructures, including the transfer behavior and mechanisms of photoexcited non-equilibrium carriers between the materials. Furthermore, the effects of recent advances and state-of-the-art designs of heterostructures on hydrogen production are discussed, offering practical approaches to form heterostructures for efficient hydrogen production.

Ultrathin Porous Carbon Nitride Anchored with Pt Nanoclusters for Synergistic Enhancement of Hydrogen Production in Alkaline Photocatalytic Polyester Reforming.

Photocatalytic reforming (PR) of polyester waste, fueled by renewable sources like solar energy, offers a sustainable method for producing clean H2 and valuable by-products under mild conditions. The design of high-performance photocatalyst plays a pivotal role in determining the efficacy of an alkaline polyester PR system, influencing H2 generation activity and selectivity. Here, ultrathin porous carbon nitride nanosheets (UP-CN) loaded with Pt nanoclusters (Pt NCs, average diameter of 1.7nm) with uniform Pt NCs distribution are introduced. The resulting Pt NCs/UP-CN catalyst can accelerate charge and mass transfer while providing additional active sites, achieving superior H2 generation rates of 11.69mmol gcat -1 h-1 and 2923mmol gPt -1 h-1 under AM 1.5 light, which nine times higher than that of Pt nanoparticles-bulk graphitic carbon nitride composite (1.29mmol gcat -1 h-1 and 258mmol gPt -1 h-1) as counterpart. This performance also surpasses that of previously reported carbon nitride-based and TiO2-based photocatalysts. Moreover, the density functional theory calculations reveal a significant reduction in the energy barrier for the water dissociation step (H2O + * → *H + OH) at the interface between UP-CN and anchored Pt NCs, showcasing the synergistic effect between Pt NCs and UP-CN. This catalytic system also exhibits universality across various polyester plastics.

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.

Engineering superhydrophilic Ni-Se-P on Ni-Co nanosheets-nanocones arrays for enhanced hydrogen production assisted by hydrazine oxidation reaction

The production of hydrogen gas as an environmentally friendly and emission-free fuel source, has emerged as the preeminent substitute for traditional fossil fuels. The demand for a viable and low-cost substitute of the anodic Oxygen Evolution Reaction (OER) in hydrogen gas production has led researchers to explore the Hydrazine Oxidation Reaction (HzOR), aiming to reduce overpotential. In this study, we present the synthesis of a NiSeP@NiCo/Cu electrocatalyst via electrodeposition method, offering precise control over parameter adjustments and an affordable price. The binder-free nanosheet structure of this electrocatalyst demonstrates improved performance in water electrolysis, resulting in potentials of −40 and −134 mV vs. Reversible Hydrogen Electrode (RHE) for Hydrogen Evolution Reaction (HER) and 0.041 and 0.194 V (vs. RHE) for HzOR (i = 10 and 100 mA.cm−2). The electrode has excellent features, including active electrochemical surface, synergistic effects among the elements, high stability, super-hydrophilicity and super-aerophobicity. The Bi-functional performance of electrode was tested in a two-electrode set for HER/HzOR, the cell voltage required to reach current densities of 10 and 100 mA.cm−2 were determined as 0.071 and 0.298 V respectively. On the whole, this work presents the excellent capabilities of the synthesized electrode (NiSeP@NiCo/Cu) for hydrogen gas production.

Prediction of hydrogen production in proton exchange membrane water electrolysis via neural networks

Advancements in water electrolysis technologies are crucial for green hydrogen production. Proton exchange membrane water electrolysis (PEMWE) is characterized by its efficiency and environmental benefits. The prediction and optimization of hydrogen production rates (HPRs) in PEMWE systems is difficult and still challenging because of the complexity of the system as well as the operational parameters. The integration of artificial intelligence (AI) and machine learning (ML) appears to be effective in optimization within the energy sector. Hence, this work employs the artificial neural network (ANN) to develop a model that accurately predicts HPR in PEMWE setups. A novel approach is introduced by employing the Levenberg–Marquardt backpropagation (LMBP) algorithm for training the ANN. This model is designed to predict HPR based on critical operational parameters, including anode and cathode areas (mm2), cell voltage (V) and current (A), water flow rate (mL/min), power (W), and temperature (K). The optimized ANN configuration features an architecture with 7 input nodes, two hidden layers of 64 neurons each, and a single output node. The performance of the ANN model was evaluated against conventional regression models using key metrics: mean squared error (MSE), coefficient of determination (R2), and mean absolute error (MAE). The findings of this study reveal that the developed ANN model significantly outperforms traditional models, achieving an R2 value of 0.9989 and an MAE of 0.012. In comparison, random forest (R2 = 0.9795), linear regression (R2 = 0.9697), and support vector machines (R2 = − 0.4812) show lower predictive accuracy, underscoring the ANN model's superior performance. This work demonstrates the efficiency of the LMBP in enhancing hydrogen production forecasts and sets a foundation for future improvements in PEMWE efficiency. By enabling precise control and optimization of operational parameters, this study contributes to the broader goal of advancing green hydrogen production as a viable and scalable alternative to fossil fuels, offering both immediate and long-term benefits to sustainable energy initiatives.

Photocatalytic Reforming of Ethanol in the Liquid Phase Using a Ternary Composite of Rh/TiO2/g-C3N4 as a Catalyst.

Photocatalytic reforming of ethanol provides an effective way to produce hydrogen energy using natural and nontoxic ethanol as raw material. Developing highly efficient catalysts is central to this field. Although traditional semiconductor/metal heterostructures (e.g., Rh/TiO2) can result in relatively high catalyst performance by promoting the separation of photoinduced hot carriers, it will still be highly promising to further improve the catalytic performance via a cost-effective and convenient method. In this study, we developed a highly efficient photocatalyst for ethanol reformation by preparing a ternary composite structure of Rh/TiO2/g-C3N4. Hydrogen is the main product, and the reaction rate could reach up to 27.5 mmol g-1 h-1, which is ∼1.41-fold higher than that of Rh/TiO2. The catalytic performance here is highly dependent on the wavelength of the light illumination. Moreover, the photocatalytic reforming of ethanol and production of hydrogen were also dependent on the Rh loading and g-C3N4:TiO2 ratio in Rh/TiO2/g-C3N4 composites as well as the ethanol content in the reaction system. The mechanism of the enhanced hydrogen production in Rh/TiO2/g-C3N4 is determined as the improvement in the separation of photoinduced hot carriers. This work provides an effective photocatalyst for ethanol reforming, largely expanding its application in the field of renewable energy and interface science.

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.

Effectively enhanced photocatalytic hydrogen production performance of novel noble metal-free Cu(OH)2/MoSe2-g-C3N4 ternary nanocomposite under visible light irradiation

The present work presents a novel copper hydroxide-molybdenum diselenide-carbon nitride (3 % Cu(OH)2/MoSe2-g-C3N4, (3CM-CN)) ternary nanocomposite catalyst. This catalyst was synthesized using a three-step process: hydrothermal synthesis, ball milling, and wet impregnation. The focus of this research is on the hydrogen generation (H₂) capabilities of this novel material. The catalyst was extensively characterized using various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS), resulting in a comprehensive understanding of its structure, morphology, optical properties, and surface composition. The catalytic activity and mechanism of Cu(OH)2/MoSe2-g-C3N4 composites were investigated. The ternary nanocomposite catalyst significantly enhanced hydrogen production, achieving rates 7.7 times greater than g-C3N4 and 4 times greater than 3 % Cu(OH)2/MoSe2 (3CM). Its maximum production reached an impressive 3012 µmol g−1 h−1. The analysis demonstrated a significant increase in active sites on the composite’s surface, accompanied by an increase in the composite-specific surface area to 73 m2/g. The development of a ternary nanocomposite led to a higher rate of catalyst production for hydrogen generation while simultaneously decreasing the rate of electron-hole recombination. It gave an innovative strategy for constructing highly efficient composite catalysts for hydrogen generation very effectively.

Self-catalysed breakdown of titanate nanotubes by graphitic carbon nitride resulting in enhanced hydrogen production

Efficient design of a photocatalyst is an important step in realizing real world applications. In this work, using in-situ catalysis we have prepared and investigated a titanate nanotube (TiNT)/ graphitic carbon nitride nanocomposite, which after optimization shows excellent hydrogen production efficiency of 2.3 mmolg−1h−1, much improved compared to GCN, which achieved a rate of 0.56 mmolg−1h−1. We can conclude that pyrolysis of urea to carbon nitride also self catalyses the breakdown of TiNT into anatase TiO2 nanoparticles, resulting in a nanocomposite material comprising TiO2 and heterojunctions with GCN. After heating and modification the TiO2 shows a conduction band edge with a more negative potential than the H+/H2 potential, which along with the ideal position of the GCN CB edge facilitates hydrogen production under light irradiation. This novel method can be viewed as a general method for improving catalysis synthesis and design, whilst simultaneously reducing the complexity and energy footprint of active catalyst synthesis.

Enhancing hydrogen production via dry reforming of methane: Optimization of Co and Ni on scandia-ceria-zirconia supports for catalytic efficiency and economic feasibility

The Novel “Scandia-ceria incorporated zirconia” (10ScCeZr) is a well-recognized material in ceramic and solid oxide electrolytes due to stable phases (like cubic ZrO2) and oxide conducting phases (like hexagonal Sc4Zr3O12 phases). The objective of the current study is to introduce 10ScCeZr as support for bearing a proportional ratio of active sites (Ni and Co), investigating catalytic performance in DRM and studying the economic viability with respect to other catalysts. The 10ScCeZr support is used first time where the concentration of ceria is minimal to minimize the risk of oxidation of active sites but achieve the benefit of mobile lattice oxygen along with scandia and zirconia. Upon dispersion of different proportions of Ni and Co over 10ScCeZr, the reducibility pattern, stability of active sites, stability of oxide vacancy, and type of carbon deposit are modified markedly. Upon using 3: 1 Ni and Co over 10ScCeZr, the crystallinity of the catalyst is minimal, and the total concentration of active site and stable active sites doesn’t fluctuate more than 5Ni/10ScCeZr, and active sites are majorly derived by NiO. During the DRM, less inert carbon is deposited over the catalyst (than 5Ni/10ScCeZr). These physiochemical modifications over 3.75Ni1.25Co/10ScCeZr result in the highest 45 % H2 yield at 700 °C and 79 % H2 yield at 800 °C at the end of 300 min. The significant high operational savings due to the 0.44 % increased H2-yield validate the long-term financial benefits upon industrialization of the current catalyst. Now, this catalyst is open for further investigation on promotors’ effect and process optimization for developing a high-performance catalyst with excellent savings in H2-production through DRM.

Drastic Enhancement of Hydrogen Production from Water in Gold–Silver Sulfide Hybrid Quantum Dot-Sensitized Photoelectrochemical Cell through Plasmon–Plasmon–Exciton Coupling

Drastic Enhancement of Hydrogen Production from Water in Gold–Silver Sulfide Hybrid Quantum Dot-Sensitized Photoelectrochemical Cell through Plasmon–Plasmon–Exciton Coupling

Plasma-Enabled Process with Single-Atom Catalysts for Sustainable Plastic Waste Transformation.

In this study, we present a novel plasma-enabled strategy for the rapid breakdown of various types of plastic wastes, including mixtures, into high-value carbon nanomaterials and hydrogen. The H2 yield and selectivity achieved through the catalyst-free plasma-enabled strategy are 14.2 and 5.9 times higher, respectively, compared to those obtained with conventional thermal pyrolysis. It is noteworthy that this catalyst-free plasma alone approach yields a significantly higher energy yield of H2 (gH2/kWh) compared to other pyrolysis processes. By coupling plasma pyrolysis with thermal catalytic process, employing of 1 wt.% M/CeO2 atomically dispersed catalysts can further enhance hydrogen production. Specifically, the 1 wt.% Co/CeO2 catalyst demonstrated excellent catalytic performance throughout the 10 cycles of plastic waste decomposition, achieving the highest H2 yield of 46.7 mmol/gplastic (equivalent to 64.4% of theoretical H2 production) and nearly 100% hydrogen atom recovery efficiency at the 7th cycle. Notably, the H2 yield achieved over the atomically dispersed Fe on CeO2 surface in the integrated plasma-thermal catalytic process is comparable to that obtained with Fe particles on CeO2 surface (10 wt.%). This innovative and straightforward approach provides a promising and expedient strategy for continuously converting diverse plastic waste streams into high-value products conducive to a circular plastic economy.

The effect of GO content on the improvement of efficient water splitting applications in ZnO/GO nanocomposites

The production of solar hydrogen presents a compelling opportunity to harness solar energy, playing a crucial role in addressing climate change and reducing reliance on fossil fuels. The progress of the hydrogen economy largely depends on establishing hydrogen production as a key foundational element. Moreover, selecting appropriate materials to support the main catalyst is vital for enhancing hydrogen production. This article furnishes a simple, affordable approach to existing water-splitting technologies that harness solar energy as the primary source for hydrogen production. To achieve this, the impact of GO content on ZnO nanoparticles/GO compositions' photoelectrochemical efficiency is studied. While all the presented samples show sensitivity to light, the sample with 0.35% GO performs the best, demonstrating the highest photocurrent density, the lowest rate of electron-hole recombination, and the greatest photoelectrochemical efficiency.