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The utilization of coal for hydrogen generation presents a multifaceted approach employing processes like coal gasification, pyrolysis, or high-temperature steam reforming. These methodologies entail reacting coal with steam or oxygen under elevated temperatures, yielding a gas mixture comprising hydrogen, carbon monoxide, and various byproducts. This paper delves into the exploration of hydrogen generation from coal, highlighting techniques such as gasification, pyrolysis, and other emerging methods. Notably, hydrogen discoveries within coal basins have garnered significant attention due to their implications for energy production and environmental sustainability. Certain coal basins harbor deposits rich in hydrogen, surpassing conventional coal reserves in their hydrogen content. These hydrogen-rich coals, including select sub-bituminous and lignite varieties, offer promising avenues for hydrogen production and utilization. However, the utilization of coal for hydrogen generation is not without its challenges. Technical hurdles, such as process efficiency and environmental concerns, demand rigorous investigation and innovative solutions. This paper addresses the challenges faced in coal-based hydrogen generation while elucidating the potential future prospects. It explores avenues for enhancing process efficiency, mitigating environmental impacts, and integrating coal-based hydrogen generation into broader energy strategies. Moreover, it underscores the importance of interdisciplinary research and collaboration in unlocking the full potential of coal for sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

A highly efficient electrode material is required to explore and apply to microbial electrolysis cell (MEC) with high hydrogen evolution reaction (HER) efficiency. Pt/C was one of the most efficient catalysts for hydrogen production in current lab research, but it was expensive and some chemicals in wastewater were prone to Pt poisoning, which was a great limitation in application. Thus, a cheap and effective nickel(II) Oxide/Y (NiO/Y) material was prepared by using Y zeolites as carrier loaded with NiO in this study, which was used in MEC to evaluate the hydrogen evolution performance in comparison with Pt/C. The results indicated that NiO/Y composites showed a competitive HER performance to Pt/C. The linear sweep voltammetry (LSV) tests and Tafel plots showed that the NiO/Y composites exhibited the best catalytic activity for HER. In the MEC tests, the NiO/Y composites cathode was comparable with the Pt/C cathode in terms of current densities and energy efficiency. The coulombic efficiency, cathodic energy efficiency rate and hydrogen production rate obtained with NiO/Y cathode MEC was 85.88 ± 6.5%, 228.39 ± 3.2% and 0.83 ± 0.05 m3/m3d under, respectively, which were slightly higher than those obtained with the Pt/C cathode MEC. It was concluded that even with the cheap Y zeolites as the supports, the NiO/Y materials showed the superior performance, which was attributed to a good dispersing of the active component of NiO on the large specific surface area of Y zeolites and the fast escape of hydrogen bubbles from microporous and mesoporous structure of Y zeolites. [ABSTRACT FROM AUTHOR]

The photo-fermentative biohydrogen production using photosynthetic purple non-sulfur and non-oxygenic bacteria Rhodobacter sphaeroides is a very promising green technology. In this paper, several strategies conducted in the literature to make the bioprocess more economical, less expensive and more efficient have been reviewed. The used of co-cultures and genetic modification strategies increased the yield and the rate of hydrogen production. Also, the biohydrogen production using organic wastes as a substrate, an environmentally friendly process, in several reactors designs with immobilized and suspension cultures have been employed to achieve a high conversion efficiency of the substrate and light energy. At the optimized conditions, the hydrogen production enhances and becomes more economic. [ABSTRACT FROM AUTHOR]

Few studies focus on the simultaneous removal performance and mechanism of H2S and SO2 mixture in Claus tail gas with a high concentration of H2O (20–30 vol.%) and CO2 (8–10 vol.%). In this paper, the effects of H2O and CO2 on the simultaneous removal of H2S and SO2 for the by activated carbon (TL-1) were studied. Fresh (TL-1-F) and desulfurisation sulfur-loaded TL-1 activated samples (TL-1-E1 and TL-1-E2) were characterised by BET, elemental analysis, TG-MS, FT-IR and XPS. The simultaneous adsorption mechanism of H2S and SO2 on TL-1 in the presence of H2O and CO2 was discussed. Results show that the breakthrough sulfur capacity of TL-1 for the simultaneous removal of H2S and SO2 mixture reaches up to 301.6 mg S/g ads when the feed gas containing 30 vol.% H2O and 8 vol.% CO2, which is 40% higher than that without H2O. H2O in the feed is adsorbed on the surface of TL-1 and forms a water film. The adsorbed H2S and SO2 are dissolved and ionised in the water film, which is conducive to the adsorption removal of H2S and SO2 by TL-1 and the generation of sulfuric acid (55.8%) and S8 (44.2%). Meanwhile, CO2 is only physically adsorbed on the surface of TL-1, and does not participate in the chemical adsorption (or chemical reaction) for the removal sulfide process. [ABSTRACT FROM AUTHOR]

In this paper the phenomenon of flame jump vis-a-vis steady propagation in biomass packed beds in counter-current mode is discussed. By analyzing the fuel flux and propagation rate data from experiments with a range of oxidizers, namely, air, O2-N2, O2-CO2, and O2-steam mixtures, parameter regimes of steady propagation, and flame jump are identified. A theoretical basis for this classification is developed by analyzing the thermo-chemical conversion of single particles subject to flow and thermal conditions in a packed bed. The ratio of the ignition ( t i g ) to devolatilization ( t v ) times is shown to emerge as the controlling parameter in determining the flame propagation regimes. It is found from the theoretical analysis that steady propagation occurs for t v / t i g < 2 and transition to flame jump occurs if t v / t i g > 2. Operational zones of a packed bed biomass system is mapped using the predicted ratio of t v / t i g as a function of volatiles-based equivalence ratio ( ϕ v ). Implications of these results to practical ligno-cellulosic biomass combustion and gasification systems, especially using oxygen-steam mixtures for hydrogen generation, are brought out. [ABSTRACT FROM AUTHOR]

4-chlorophenol (4-CP) could be rapidly mineralized by using Fenton reaction. However, massive iron sludge will be generated because of the excessive consumption of iron salt and poor recycling of FeIII back to FeII. In this paper, by introducing hydrogen gas and solid catalyst Pd/NH2-MIL-101(Cr) to classic Fenton reactor, the novel system named MHACF-NH2-MIL-101(Cr) was constructed. Much less FeII was needed in this system because the hydrogen could significantly accelerate the regeneration of FeII. The catalyst improved the utilization of H2. The degradation reaction of 4-CP could be driven by using only trace amount of FeII. It could be rapidly degraded by the hydroxyl radical detected by the 4-Hydroxy-benzoicacid which is the oxidative product of benzoic acid and hydroxyl radical. The effects of dosage of ferrous salt, H2O2 and catalyst, H2 flow, Pd content, and initial pH of and concentration of 4-CP aqueous solution were investigated. The robustness and morphology changes of this catalytic material were also systematically analysed. By clarifying the role of this solid MOFs material in this hydrogen-mediated Fenton reaction system, it will provide a new direction for the research and development of advanced oxidation processes with high efficiency and low sludge generation in future. [ABSTRACT FROM AUTHOR]

As the reserve of prime coking coal is low, there is a good amount of research going on worldwide to improve the coking potential of non-coking coal. Researchers have revealed the importance of hydrogen generation/transfer to improve the coking potential of coal. Based on this hypothesis, in this paper, the authors have tried to improve the coking potential of non-coking coal by adding different polymers. The polymers are derived from formaldehyde and phenol derivatives. Coking potential has been tested through conventional tests like crucible swelling number. Thermogravimetric mass spectroscopy (TG-MS) has been used to get an idea of plasticity and hydrogen generation in the plastic zone. High-temperature microscopy has also been used to evaluate the swelling of coal. Results indicate that the addition of polymers in a small percentage has an effect on hydrogen generation in the plastic zone, and thus, it can improve the coking potential of non-coking coal. [ABSTRACT FROM AUTHOR]

Understanding the effect of the liquid depth (z) on the acoustic generation of hydrogen is highly required for designing large-scale sonoreactors for hydrogen production because acoustic cavitation is the central event that initiates sonochemical reactions. In this paper, we present a computational analysis of the liquid-depth effect on the generation of H2 from a reactive acoustic bubble trapped in water irradiated with an attenuating sinusoidal ultrasound wave. The computations were made for different operating conditions of frequency (355–1000 kHz), acoustic intensity (1–5 W/cm2), and liquid temperature (10–30°C). The contribution of the acoustic wave attenuation on the overall effect of depth was appreciated for the different conditions. It was found that the acoustic generation of hydrogen diminished hardly with increasing depth up to z = 8 m, and the depth effect was strongly operating parameter-dependent. The sound wave attenuation played a crucial role in quenching H2 yield, particularly at higher z. The reduction of the H2 yield with depth was more pronounced at higher frequency (1000 kHz) and lower temperature (10°C) and acoustic intensity (1 W/cm2). The attenuation of the sound wave may contribute up to 100% in the overall reductive effect of depth toward H2 production rate. This parameter could be imperatively included when studying all aspects of underwater acoustic cavitation. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide generation during contact of aqueous ozone with activated carbon surface is an established process. However, no systematic research concerning this phenomenon has been conducted. In this paper, factors affecting H2O2 generation are presented. Formation of hydrogen peroxide in contact of ozone with carbon is a surface phenomenon, strongly affected by the solution pH. Re-ozonation of the same carbon sample does not lead to H2O2 generation. Additionally, the amount of generated H2O2 is significant only in strongly acidic environment. It implies that hydrogen peroxide generated by surface of activated carbon cannot be ozone decomposition initiator in catalytic ozonation based on activated carbon as a catalyst. [ABSTRACT FROM AUTHOR]

Our group has developed a series of molecular electrocatalysts for hydrogen generation based on triazenido-metal complexes (such as cobalt, copper, etc.). In this paper, we present the electrocatalytic performance of a new dinuclear silver complex, [Ag2(L)2], formed by reaction of the triazenido ligand, 1-[(2-carboxyethyl)benzene]-3-[benzimidazole]triazene (HL) with AgNO3. The electrocatalytic systems based on this silver complex can afford 91.23 and 473 moles of hydrogen per mole of catalyst per hour (mol H2/mol catalyst/h) from acetic acid at overpotential (OP) of 991.6 mV and an aqueous buffer at an OP of 837.6 mV, respectively. Electrochemical investigations show both the silver center and the triazenido ligand, HL, play important roles in determining the catalytic activities of the electrocatalytic system. Additionally, the triazenido ligand (HL) can serve as a fluorescent sensor for Ag+. [ABSTRACT FROM AUTHOR]

Evaluations of severe accident conditions for water-cooled reactors with metallic fuel pin cladding must consider the oxidation of this material for accident sequences that could lead to high metal temperatures in a steam environment. Such representations are included in integral accident analysis computer codes. If the oxidation causes sufficiently high temperatures to melt, or liquefies the core materials, the core geometry changes as the melt drains downward and freezes on cooler structures promoting blockages and redirection of steam flowing through the fuel assemblies. Once this configuration forms, the accident condition is characterized as the late phase of core oxidation. The Phebus in-reactor experiments investigated hydrogen generation in this compacted core state and measured the generation rates over several thousand seconds. This paper investigates the role of countercurrent steam-hydrogen flow to the debris upper surface as a limit for the generation rate and finds that this provides a close description of the behavior for the Phebus experiments. Applying this mechanism to reactor accident conditions shows how this should be considered in the Severe Accident Management Guidelines. [ABSTRACT FROM AUTHOR]

The efficient utilization of wood waste is important for protecting the environment and solving the energy shortage problem. Taking Fraxinus mandshurica (FM) as an example, polyoxometalate (POM) was used as a catalyst for cyclic redox in an H-type electrolytic cell, where wood was oxidized to valuable small-molecule chemicals at the anode and hydrogen was generated at the cathode. The system successfully recycles energy, simultaneously converting biomass to chemical and electrical to hydrogen. Furthermore, the effects of various factors on the reaction were also investigated to obtain the optimal electrochemical conversion results for wood waste. At the optimal conditions, the FM degradation rate of 56.1%, with aromatic organic and carbonyl compounds as the main products, and the average Faraday efficiency of hydrogen generation can reach 93%, saving about 40% of energy consumption compared to water electrolysis at 0.1 A cm−2. Therefore, this electrochemical conversion method provides a new potential pathway for the application of wood waste. [ABSTRACT FROM AUTHOR]

A microscale Fe/Ni bimetallic particle was examined to convert O2 to H2O2 and further to •OH radicals and to degrade metronidazole (MNZ) antibiotic in a heterogeneous Fenton-like reaction. The properties of the bimetallic particle before and after the reaction were studied using SEM, EDX, XRD, and BET techniques. The complete removal of MNZ was achieved within 15 min with an initial pH of 3, oxygen flow rate of 150 L/h, Fe/Ni of 1 g/L, and MNZ of 25 mg/L. Under these conditions, the maximum H2O2 concentration of about 31 mg/L was generated but only 27% of TOC was removed after 60 min. The presence of NaCl and the high ionic strength accelerated the iron dissolution and MNZ removal efficiency. The reaction was mainly inhibited at the solution pH of 7, implying the significance of solution pH in Fenton-like process. Besides, the possible MNZ degradation pathway was further proposed based on the intermediates identified by GC/MS. Acetamide was monitored as the degradation intermediate. The results showed a significant contribution on the usage of a catalyst for in-situ generation of H2O2 via the activation of dissolved oxygen. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) is examined as a fuel and as one of the most extensively studied substitute energy resources for available sources that are being consumed rapidly. Thus, the growing interest in the development of competitive, low-cost hydrogen production leads us to devote particular efforts to establish efficient processes in an economical and environmentally benign way. In this view, both photochemical and electrochemical processes have been exclusively investigated as greener paths for hydrogen production. The present review article highlights the process established for hydrogen generation over the last few years. The overall thrust of the present theme is a discussion of the efforts that have been made so far for finding hydrogen as an alternative fuel from different feedstock through photochemical and electrochemical processes. [ABSTRACT FROM AUTHOR]

To better understand the MELCOR oxidation and degradation models, past work compared the MELCOR model to a CORA experiment (CORA Test 13). These MELCOR analyses specifically focused on fuel bundle heatup and clad oxidation when compared to CORA test data. The comparison allowed the authors to investigate differences between hydrogen generation data and simulation results. Several potential reasons were considered for hydrogen generation rate differences, including MELCOR input power, heat transfer modeling, the clad solid-phase oxidation model, and the gaseous steam diffusion model. This work focuses on the possible uncertainty in the clad oxidation models used in MELCOR. First, the MELCOR nodalization approach for the CORA test was reviewed. Then, the temperature history and spatial variation were examined. One main focus was to consider other clad solid-phase oxidation models to compare the MELCOR models. This was accomplished by developing a separate model, MYCOAC, using MELCOR temperature predictions as input. Finally, the mass transfer resistance of steam diffusion to the clad suiface was examined and found to be a small effect. While the Baker-Just solid-phase oxidation model showed better agreement with CORA data at low temperatures, the conclusion in this paper is that the oxidation models are not the major source of uncertainty in hydrogen generation rate differences. Future work will focus on heat transfer modeling of the CORA test. [ABSTRACT FROM AUTHOR]

In this study, an integrated hybrid polygeneration system based on solar and biogas energy is developed for simultaneous heat and power generation and hydrogen production. A heat recovery system is employed, which can recover the waste heat from the flue gas for effective utilisation in the steam network. The devised system, comprising solar, biogas, chemical, steam, and power islands, is investigated and comparatively evaluated through energy and exergy approaches. Additionally, an optimisation study is carried out to find the optimal exergy efficiency. The findings suggest that integrating the steam island and hybrid system improved the overall system performance significantly. The optimisation results demonstrate the value of 58.06% for exergy efficiency, while energy efficiency is also increased from 60.55% to 65.94%. [ABSTRACT FROM AUTHOR]

The reaction of NiCl2, K2(i-mnt) (i-mnt2−= 2,2-dicyanoethylene-1,1-dithiolate) and 1-benzyl-4-amino-pyridinium bromide [BzPyNH2]Br affords a nickel complex, [BzPyNH2]2[Ni(i-mnt)2], a molecular catalyst for electrochemical and photochemical driven hydrogen evolution. As an electrocatalyst, [BzPyNH2]2[Ni(i-mnt)2] can electrocatalyze hydrogen generation from a neutral buffer with a turnover frequency (TOF) of 556 (±3) mol of hydrogen per mole of catalyst per hour (mol H2/mol catalyst/h) at an overpotential (OP) of 837.6 mV. As a photocatalyst, combining with CdS nanorods (CdS NRs) as a photosensitizer, and ascorbic acid (H2A) as a sacrificial electron donor, [BzPyNH2]2[Ni(i-mnt)2] photocatalyzes hydrogen evolution in heterogeneous environments with a turnover number (TON) of 18420 (±5) mol H2 per mol of catalyst during 60 h irradiation. The highest apparent quantum yield (AQY) is ∼10% at 469 nm. Several chemical and physical methods are employed to understand catalytic procedures for H2 production. [ABSTRACT FROM AUTHOR]

4-Phenyl-3-thiosemicarbazide reacts with 2,3-butanedione to provide a new compound, diacetyl-bis(N4-phenyl-3-thiosemicarbazonato) (H2ATSP). In the presence of triethylamine (Et3N), the reaction of H2ATSP with NiCl2 affords a new nickel complex, diacetyl-bis(N4-phenyl-3-thiosemicarbazonato)nickle(II) (NiII-ATSP), a diamagnetic material, which has been characterized by physicochemical and spectroscopic methods. Studies exhibit that Ni-ATSP has good catalytic activities for both electrochemical and photochemical driven hydrogen evolution. Under an overpotential (OP) of 837.6 mV, 188.7 moles of hydrogen per mole of catalyst per hour (mol H2/mol catalyst/h) are afforded from an electrolysis of neutral water with Ni-ATSP. With blue light (λ = 469 nm) irradiation, together with CdS nanorods (CdS NRs) as a photosensitizer, and ascorbic acid (H2A) as a sacrificial electron donor, Ni-ATSP can catalyze hydrogen generation with a turnover number (TON) of 9554 moles H2 per mol of catalyst (mol of cat−1) during 50 h irradiation in a heterogeneous environment. [ABSTRACT FROM AUTHOR]

Fermentative hydrogen production is considered as a promising source of renewable energy, and bacterial strain is an essential factor influencing hydrogen production. In this study, a high hydrogen-producing fermentative strain was isolated from a sugar plant, and identified as Clostridium sp. 5A-1 by 16S rRNA analysis. Strain 5A-1 was found to be a robust hydrogen-producing fermentative bacterium, which could produce hydrogen under a wide range of temperature (25°C–50°C) and initial pH (pH 5–9). The optimum culture temperature and initial pH for hydrogen production was 43°C and pH 7.5, respectively. The glucose concentration of 10 g/L resulted in the highest hydrogen production (1847 mL/L) and hydrogen production rate (231 mL/L.h), and 7 g/L glucose was the optimum substrate concentration for hydrogen yield (1.92 mol/mol glucose). Thus, Clostridium sp. 5A-1 is a potential candidate for fermentative hydrogen production. [ABSTRACT FROM AUTHOR]

Ru-Co/CNTs catalysts are prepared by microwave-assisted heating electroless plating using Carbon nanotubes as Carrier. The structure of the catalyst was analyzed by TEM, XRD, EDS and TGA, and the performance of the catalytic alcoholysis of sodium borohydride was tested. At 25 oC, the carbon nanotube diameter is 10-20 nm, the catalyst dosage is 20 mg, the sodium borohydride concentration is 5 wt.%, and the sodium hydroxide concentration is 7 wt.%, the maximum rate of catalytic hydrogen production reaches the maximum value. At the same time, the activation energy is calculated to be 34.35 kJ · mol-1, which is much lower than the activation energy of spontaneous alcoholysis of sodium borohydride (63.0 kJ/mol). [ABSTRACT FROM AUTHOR]

We report how four sets of thiourea-based heterodimers interact, and how incorporation of a metal centre imparts reduced degrees of rotational freedom. Through single-crystal X-ray diffraction, 1H NMR, and UV-vis analysis, the interactions of these systems are dissected and presented. These motifs are considered to be stable and desirable for supramolecular hydrogen-bonded functional materials. Interpretation of the structural design of thiourea-based ligand and its incorporation into metal complexes can contribute to the understanding of preorganised self-assembly and open new pathways in design of novel soft materials. This work also contributes to the unexplored library of hydrogen-bonded metal complexes based on iridium. As such we examined the photoluminescence of the system of general formula [Ir(C^N)2(N^S)] and the effect of hydrogen bonding on the emission properties when combined with different n-heteroacenes. [ABSTRACT FROM AUTHOR]

This assay investigates the Co-Cr-B catalyst effect supported on γ-Al2O3 to produce hydrogen (HG) from ammonia-borane hydrolysis (ABH). For characterization of this catalyst, SEM-EDX, XRD, FTIR and BET surface area analysis were performed. The maximum hydrogen generation rate (HGR) with this catalyst used for the ABH was 3260 ml min−1 g−1catalyst. The recyclability tests for the Co-Cr-B/γ-AlO3 catalyst on the ABH have maintained an activity of 68% even after four hydrolysis treatments. Also, the activation energy (Ea) obtained using the Co-Cr-B catalyst supported on γ-AlO3 for the ABH was 56.06 kJ/mol. [ABSTRACT FROM AUTHOR]

In the present study, the authors developed a new numerical model to predict the bulk fluid flow, heat transfer, hydrogen species transfer with the hydrogen bubble generation, dynamics and trapping during solidification of aluminium through the continuum theory with Lagrangian bubble dynamics. The generated bubble size is assumed to be dependent on the microstructure. The bubble drag force is newly proposed in the Euler-Lagrange framework. In a model casting system, almost all generated hydrogen bubbles are trapped into a solidified aluminium. However, the hydrogen bubbles are capable of generating in the melt phase and detaching from the mushy zone when the initial hydrogen concentration is high. In this case, the hydrogen bubbles move upward due to buoyancy and this movement is slightly affected by the surrounding melt flow. [ABSTRACT FROM AUTHOR]

Two of dihydropyridine derivatives, namely, 4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (DPCN) and 4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carboxamide (DPCA) were evaluated as controllers for H2 production during the dissolution of Zn in dilute HCl. Different chemical (thermometry, gravimetry, and gasometry) and electrochemical (potentiodynamic polarization and impedance) techniques were used. SEM and optical profilometry surface investigations for some corroded and un-corroded Zn samples were carried out to describe the Zn surface during the dissolution process. The rate of H2 production was found to increase with the immersion time and temperature and was lowered by the inhibitor. The potentiodynamic data proved that DPCN and DPCA inhibit the dissolution of Zn according to a mixed-type mechanism. [ABSTRACT FROM AUTHOR]

There are different methods of fast hydrogen generation by reaction of metal powder with water. Fundamental study of combustion of aluminum-water compositions with frozen water (aluminum-ice [ALICE]) is of great interest for the rocket technique applications. New solid hydro-reactive compositions of ALICE type on the base of permeable micro-porous metal-polymer matrices filled with water is reported. Magnesium (Mg) powder of 80 μm was chosen as a combustible. Combustion characteristics for these compositions in a nitrogen or argon atmosphere at different pressures were studied. It was found that the burning rate was 12-18 mm/s in the wide pressure range up to 80 atm, as the pressure exponent was close to zero. It was shown that the presence of a thin agglutinant polymer film on the Mg particle of the metal-polymer matrix did not significantly affect the burning rate of samples in comparison with mixtures of Mg powder with water but resulted in some combustion peculiarities. Preliminary experiments studying the combustion wave propagation along the metal-polymer matrix surface in water steam were carried out. [ABSTRACT FROM AUTHOR]

A 100 W proton exchange membrane fuel cell (PEMFC) system with a sodium borohydride (NaBH4) hydrogen generator was investigated for small unmanned aerial vehicles (UAVs). The performance of a cobalt-phosphorous/nickel foam catalyst was evaluated to determine the change in catalytic activity under real operating conditions. The response time increased owing to oxidation of the metals and accumulation of sodium; however, the catalyst remained active at high reaction temperatures. A NaBH4 hydrogen generator with the catalyst was developed for a 100 W PEMFC system. The hydrogen generation rate was stable for 3 h, and the conversion efficiency was 97.8%. Finally, a 100 W PEMFC system with the NaBH4 hydrogen generator was investigated for small UAVs. The maximum power and energy density of the PEMFC system were 95.96 W and 185.2 Wh/kg, respectively. [ABSTRACT FROM AUTHOR]

As the most abundant metal on the earth, aluminum is one of alternative clean fuels. This work presents experimental studies on the reaction process characteristics in a specially designed reactor using Al-based metals as fuel. The experiments of different samples with steam in a thermogravimetric analyzer and special designed reactor indicated that Al–Li alloy had a better reactivity than Al–Mg–Li. The efficiency was 87.83% and H2 yield reached 1155.03 ml/g for Al–Li alloy. It is feasible to use Al–Li alloy as fuel to provide H2 and heat. [ABSTRACT FROM AUTHOR]

An environment-friendly graphene reinforced slag-based nanocomposite (GRSN) was synthesized by incorporation of two-dimensional lamellar graphene into the alkali-activated blast-furnace slag-based cementitious-material (ABSC), and firstly used as an excellent catalyst for solar photocatalytic hydrogen generation. The mechanical testing results indicated that the compressive and flexural strengths of ABSC were prominently reinforced by the incorporation of graphene. The X-ray diffraction (XRD) results showed that the GRSN powder mainly contained the network structure of calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH). The photoluminescence spectra implied that the separation efficiency of photo-excited electrons and holes increased with the increasing graphene. The yield of hydrogen gradually ascended with the amount of graphene incorperated. The highest H2 yield of 1928.6 µmol/g for 0.02GRSN sample is ascribed to the synergistic effect of graphene and semiconductor oxides of TiO2 and Fe2O3 deriving from the ABSC. [ABSTRACT FROM AUTHOR]

Hydrogen generation by the reaction of Al–NaCl mixtures with water was investigated over the 30–70°C temperature range. 5, 10, and 20 wt% of NaCl were added to Al powder and ground by planetary ball milling. The addition of NaCl activated the powders and prevented cold welding of Al powders during ball milling process. Smaller particle size and deformed microstructure accelerated the corrosion rate of aluminum with water. The results showed that 20 wt% NaCl, 12 h ball milling time, and 70°C reaction temperature effectively enhanced the hydrogen generation rate of the powders. [ABSTRACT FROM PUBLISHER]

Ammonia borane (NH3BH3, AB) has a hydrogen capacity of 19.6 wt-%, exceeding that of gasoline and making itself an attractive candidate for hydrogen storage applications. Great efforts have been paid to research the low cost and highly efficient catalysts for hydrogen generation from the hydrolysis or methanolysis of AB in the past decade. Copper is admitted as being a promising catalyst, being as reactive as noble metals and much more cost effective. In this review, we focus on the research progresses of the Cu based nanocatalysts in dehydrogenation from AB for chemical hydrogen storage. [ABSTRACT FROM AUTHOR]

An efficient and cheap catalyst, montmorillonite supported Ru nanoclusters (Ru/MMT) were successfully prepared and explored for the hydrogen generation from alkaline NaBH4solution. The catalytic behavior and the kinetics of Ru/MMT catalyzed hydrolysis of alkaline NaBH4was studied detailedly by measuring the volume of generated hydrogen gas varying catalyst concentration and temperature. The relationship between the activation energy (Ea) of NaBH4hydrolysis reaction and Ru/MMT amount was constructed, and the minimum value was determined to be 49.6 kJ/mol, which was lower than the most reported Ru-based supported catalysts that have been reported in the open literatures. The higher catalytic activity of Ru/MMT was due to the more open frame of montmorillonite than the other inorganic supporters, which decreases the substrate inhibition in catalytic hydrolysis of NaBH4. [ABSTRACT FROM AUTHOR]

We report that hydrogen gas can be easily produced from water at room temperature using a Mg nanopowder (30-1000 nm particles, average diameter 265 nm). The Mg nanopowder was produced by dc arc melting of a Mg ingot in a chamber with mixed-gas atmosphere (20% N2-80% Ar) at 0.1MPa using custom-built nanopowder production equipment. The Mg nanopowder was passivated with a gas mixture of 1% O2 in Ar for 12 h in the final step of the synthesis, after which the nanopowder could be safely handled in ambient air. The nanopowder vigorously reacted with water at room temperature, producing 110 ml of hydrogen gas per 1 g of powder in 600 s. This amount corresponds to 11% of the hydrogen that could be generated by the stoichiometric reaction between Mg and water. Mg(OH)2 flakes formed on the surface of the Mg particles as a result of this reaction. They easily peeled off, and the generation of hydrogen continued until all the Mg was consumed. [ABSTRACT FROM AUTHOR]