Abstract To obtain Al alloys possessing the excellent hydrogen-generation performance with high efficiency/low cost via the hydrolysis reaction of aluminum with water, a series of as-cast Al alloys (∼10 g) alloying by 13 kinds of Ga-based low melting point alloys with different contents were prepared by the high frequency induction melting method under a high purity argon atmosphere. The effect of the content and composition of the low melting point alloys on the hydrogen-production property of Al alloys ingots with the tap water was systematically investigated. The relationship among the hydrogen production performance, the microstructure, and the phase constituents of these Al alloys was investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy disperse spectroscopy and differential scanning calorimeter (DSC). Compared with conventional activated Al alloys powders prepared by the ball-milling method, the as-cast bulk Al alloys show the same excellent properties of hydrogen production, i.e., the high hydrogen-generation ratio but slower and more persistent hydrogen generation rate. The preparation method of Al-alloy ingots is simple, convenient, low preparation cost and high efficient, compared with the ball-milling method, which shows the significant industrial application value and prospect. Besides, the activation mechanism of the Al-water reaction dynamics was revealed on the basis of the analysis of the microstructure, phase composition and related literature.
In this study, (Al0.5CrFeNiTi0.25)Nx high-entropy films are prepared by a reactive direct current (DC) magnetron sputtering at different N2 flow rates on silicon wafers. It is found that the structure of (Al0.5CrFeNiTi0.25)Nx high-entropy films is amorphous, with x = 0. It transforms from amorphous to a face-centered-cubic (FCC) structure with the increase of nitrogen content, while the bulk Al0.5CrFeNiTi0.25 counterpart prepared by casting features a body-centered-cubic (BCC) phase structure. T...
Abstract The effective parameters for the Al-water reaction are studied. Salts such as sodium chloride (NaCl), potassium chloride (KCl) and barium chloride (BaCl2) were added to Al particles and the mixture were alloyed via high-energy ball milling. It was observed that the reaction of Al/water is evolved and the reaction induction time declined significantly by the application of BaCl2 as new modifier in comparison with NaCl and KCl. The X-ray diffraction patterns revealed that the other valuab...
Abstract Al-Bi alloys and Al-Bi-C composites with different compositions were synthesized by high-pressure torsion (HPT) and their hydrogen generation behavior via hydrolysis was investigated in contact with pure water. Bi was added to Al to enhance the effect of nano-galvanic cells and to promote the pitting corrosion, and C in the form of graphite was added to Al to accelerate the fragmentation of the composite and to increase the total active surface area. An optimized Al-30 wt%Bi-10 wt%C com...
Last. Cuiping Wang(Ha Tai: Xiamen University)H-Index: 22
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Abstract Highly activated Al-based composite powders with compositions of Al-20Bi and Al-20Sn (wt.%) were prepared by gas atomization method for hydrogen generation. The Al-20Bi powders formed incomplete core–shell structure with Bi aggregating on the powder surface, while the Al-20Sn powders presented eutectic structure with Sn distributed homogeneously on the grain boundaries of Al. The hydrolysis characteristics of these powders were investigated in distilled water. The results showed that th...
Abstract Possibility of effective hydrogen generation by the water steam barbotage through the aluminum melt was demonstrated experimentally. The reactor was created and a burner device with the volumetric matrix was used for melting of aluminum and generation of water steam in the reactor. The hydrogen generation regimes were analyzed. The maximum hydrogen yield of 40% was reached for steam flow rate not above than 0.01 g/s. Admixture of 10wt % KOH in aluminum increased the hydrogen yield up to...
Last. Kefa Cen(ZJU: Zhejiang University)H-Index: 77
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In order to recover the released heat of Al–H2O reaction and promote the reaction itself, the hydrogen production processes of aluminum with lithium addition in molten state are investigated. Experiments are conducted by both a thermogravimetric analyzer and a special experimental facility at high temperature. The results on both apparatuses show that the addition of Li can promote the reactivity of aluminum with water. Compared with pure aluminum, only 5% of Li content can achieve a great impro...
Last. Kefa Cen(ZJU: Zhejiang University)H-Index: 77
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Aluminum (Al) is a promising hydrogen carrier. Continuous reaction of pure Al and water (H2O) cannot proceed smoothly because Al particles are covered with a protective oxide layer. Thus, 20% Mg, Li, Zn, Bi, and Sn content were added as additives to Al–H2O reaction at high temperature. Thermogravimetric experiments were conducted to determine the reactivity of pure Al and five other samples with additives in a vapor atmosphere. Experiments indicated that Mg and Li drove the Al–H2O reaction, but ...
Abstract An Al-Ga-InSn4-InBi quinary alloy was prepared by a simple smelting and casting method. The phase components and microstructures of the quinary alloy were investigated by means of XRD and SEM with EDX. Two different intermetallic compounds of InBi and InSn4 were simultaneously found in the alloy. Al-Ga-In3Sn and Al-Ga-InSn4 quaternary alloys were prepared in the same way for comparison purpose. The reactions of alloys with water were performed at different water temperatures ranging fro...
Last. Jian-Ge Zhou(JSU: Jackson State University)H-Index: 6
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Abstract A high-activity Al(OH) 3 suspension is prepared by the reaction of Al with water using an ultrasonic procedure. The above Al(OH) 3 suspension could considerably promote the Al-water reaction and hydrogen-generation under ambient condition. This Al(OH) 3 suspension has a good stability in air and its activity increases with decreasing the particle sizes of Al powder to prepare it. The mechanism analyses reveal that the Al(OH) 3 particles in ultrasonically prepared Al(OH) 3 suspensions ar...
Last. Zhen-Yan Deng(SHU: Shanghai University)H-Index: 12
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SUMMARY Hydrogen generation by the reaction of pure Al powder in water with the addition of Al(OH)3, γ-Al2O3, α-Al2O3, or TiO2 at mild temperatures was investigated. It was found that the reaction of Al with water is promoted and the reaction induction time decreases greatly by the above hydroxide and oxides. X-ray diffraction analyses revealed that the hydroxide and oxide phases have no any change during the Al–water reaction, indicating that they are just as catalysts to assist the reaction of...
Last. Jianmin Li(BIT: Beijing Institute of Technology)H-Index: 5
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Abstract Activated aluminum composites have received widespread attention because they can generate hydrogen by reacting with water at room temperature quickly and easily. Regulating the hydrogen generation rate of activated aluminum composites is urgent, and it is a challenging task for the application of activated aluminum composites in industrial hydrogen generation. Herein, three types of carbon materials with different morphologies are used to prepare three corresponding activated aluminum ...
#1Hui Liang(DUT: Dalian University of Technology)H-Index: 3
#2Dongxu Qiao(DUT: Dalian University of Technology)H-Index: 6
Last. Tongmin Wang(DUT: Dalian University of Technology)H-Index: 34
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Abstract To evaluate the potential of high entropy alloys for marine applications, a new high entropy alloy coating of AlCrFeNiW0.2Ti0.5 was designed and produced on Q235 steel via laser cladding. The microstructure, microhardness and tribological performances sliding against YG6 cemented carbide, GCr15 steel and Si3N4 ceramic in seawater were studied in detail. The AlCrFeNiW0.2Ti0.5 coating showed an anomalous ‘sunflower-like’ morphology and consisted of BCC and ordered B2 phases. The microhard...
Abstract null null Hydrogen is becoming important clean energy while zerovalent iron (ZVI) and ferroferric oxide are of great interest to many applications including environmental remediation and chemical catalysis. Here, we report production of hydrogen, zerovalent iron and ferroferric oxide octahedron by etching Al–Fe alloys using NaOH solutions. The rate of hydrogen generation increased with increasing NaOH concentration and the alloy's particle size and decreasing the alloy's Fe concentratio...
a bstract In this study, different types of waste aluminum produced in daily life and their pure equivalents were evaluated and compared in terms of their hydrogen generation performance through the water-splitting reaction. An experimental system was designed for the production process that consisted of electrodes, DC power supply, alkaline solution, and various waste aluminum products. The hydrogen generation rate of the aluminum source was then measured to determine the optimum conditions for...
Abstract null null Semi-solid AlGaInSn bulk was fabricated for hydrogen production by Al-water reaction, of which the semi-solid structure was characterized by near-sphere primary phases dispersed within active metals enriched fine secondary-solidification-structures. The unique structure gives rise to a dramatic hydrogen production compared with the cast counterpart, although uneven throughout the whole bulk and hard to control. The underlying mechanism is demonstrated that owing to the fractur...
Abstract null null Electric vehicles are a viable alternative for internal combustion engine cars to overcome transportation problems due to high fossil fuel consumption and greenhouse gas emissions. Due to their direct current motor and battery technologies' technological development, they have become an efficient transportation option in the last decades. However, the rapid spread of electric vehicles will bring huge dump problems for the environment. Thus, policies related to the recycling of...
Last. Liuzhang Ouyang(SCUT: South China University of Technology)H-Index: 50
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The potential of a multiphase Al-Li alloy with the unreported Al1.08Li1.92 phase, for use as a hydrolytic material to produce hydrogen was studied. This alloy enabled rapid hydrogen release in a wide temperature range with roubst hydrogen yield. It could produce 1496 ml H2 g-1 within merely 0.5 min at 299 K and release 1076 ml H2 g-1 in 0.5 min even at a subzero temperature of 243 K. The hydrogen production kinetics was confirmed with a chemical step and could be well-controlled by tailoring the...
As an environmentally friendly and high-density energy carrier, hydrogen has been recognized as one of the ideal alternatives for fossil fuels. One of the major challenges faced by “hydrogen economy” is the development of efficient, low-cost, safe and selective hydrogen generation from chemical storage materials. In this review, we summarize the recent advances in hydrogen production via hydrolysis and alcoholysis of light-metal-based materials, such as borohydrides, Mg-based and Al-based materi...
Abstract The hydrolysis of Mg-based alloys and their hydrides with high abundance on the earth and low cost could produce hydrogen with high theoretical capacity and the formation of by-products that have no pollution to the environment. Hence, it has been regarded as one of the most promising way for hydrogen generation. Particularly, a gravimetric capacity of 6.4 wt% and 3.4 wt% H2 could be produced from the hydrolysis of pure Mg and MgH2, respectively, even when stoichiometric water is includ...