A Potential Hydrogen Sources from Milled Silicon Powder Activated by Lithium, and Aluminum Chloride

2017 ◽  
Vol 20 (3) ◽  
pp. 123-127
Author(s):  
Tianchu Yin ◽  
Hongwei ShenTu ◽  
Chengqiao Xi ◽  
Xin Chen ◽  
Wenzhen Zou ◽  
...  
Keyword(s):  
Particle Size ◽  
Aluminum Chloride ◽  
Hydrogen Generation ◽  
Silicon Powder ◽  
Hydrolysis Rate ◽  
Hydrogen Yield ◽  
Silicon Matrix ◽  
Pure Silicon ◽  
Hydrolysis Of ◽  
Silicon Activity

A potential hydrogen source generated from milled Li-Si-AlCl3 composite was evaluated in this paper. The composite exhibits good hydrogen generation performance in water at 313–343 K, whereas pure silicon powder cannot continuously react with water under similar conditions. The hydrogen yield reaches 1300 mL hydrogen/g within 20 min, and the highest hydrogen generation rate is higher than 1200 mL hydrogen/g min within the first minute of hydrolysis. The hydrogen generation performance increases with increasing concentrations of lithium and aluminum chloride. Microstructure analysis indicates that silicon activity increases due to decreased particle size and distribution of lithium and aluminum chloride into silicon matrix during milling. The hydrolysis of the additives generates heat and alkaline hydrolysis byproducts, thereby stimulating the hydrolysis rate of silicon in the micro area. Therefore, the hydrolysis of silicon in water may act as a potential hydrogen source for portable micro fuel cells.

Hydrogen Generation by Hydrolysis of the Ball Milled Al-C-KCl Composite Powder in Distilled Water

2012 ◽  
Vol 519 ◽  
pp. 87-91 ◽  
Author(s):  
Xia Ni Huang ◽  
Zhang Han Wu ◽  
Ke Cao ◽  
Wen Zeng ◽  
Chun Ju Lv ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Fine Particle ◽  
Composite Powder ◽  
Hydrogen Generation ◽  
Aluminum Particle ◽  
Generation Rate ◽  
Composite Powders ◽  
Fine Particle Size ◽  
Hydrolysis Of

In the present investigation, the Al-C-KCl composite powders were prepared by a ball milling processing in an attempt to improve the hydrogen evolution capacity of aluminum in water. The results showed that the hydrogen generation reaction is affected by KCl amount, preparation processing, initial aluminum particle size and reaction temperature. Increasing KCl amount led to an increased hydrogen generation volume. The use of aluminum powder with a fine particle size could promote the aluminum hydrolysis reaction and get an increased hydrogen generation rate. The reaction temperature played an important role in hydrogen generation rate and the maximum hydrogen generation rate of 44.8 cm3 min-1g-1of Al was obtained at 75oC. The XRD results identified that the hydrolysis byproducts are bayerite (Al(OH)3) and boehmite (AlOOH).

scholarly journals Research on hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution

2019 ◽  
Vol 118 ◽  
pp. 03048
Author(s):  
Changchun Li ◽  
Yuxin Wu
Keyword(s):  
Hydrogen Production ◽  
Kinetic Model ◽  
Sodium Fluoride ◽  
Hydrogen Generation ◽  
Hydrogen Yield ◽  
Shrinking Core Model ◽  
Fluoride Solution ◽  
Shrinking Core ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

Hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution was investigated through a hydrolysis experiment. Rapid and instant hydrogen yield were observed using sodium fluoride as additive. The experimental results demonstrate that the increase of temperature and the amount of additives in a certain range will boost the hydrogen production. The amount of additives outside the range only has an effect on the rapid hydrolysis of the aluminum during the initial stage, but the total amount of hydrogen produced doesn’t increased significantly. Theoretical analysis of the effects of the mixing ratio and the temperature on the hydrogen production rates were performed using the shrinking core model and the kinetic model. The shrinking core model parameter a and k indicate the film change degree of porosity and thickness and the effect of time on the diffusion coefficient. the kinetic model is verified and the activation energy confirming hydrogen yield control by a molecular diffusion process. Correspondingly, mechanisms of Al corrosion in NaF solutions under low and high alkalinity were proposed, respectively.

Hydrolysis of MgH2 in MgCl2 solutions as an effective way for hydrogen generation

2021 ◽  
pp. 38-52
Author(s):  
V. Berezovets ◽  
◽  
A. Kytsya ◽  
Yu. Verbovytskyy ◽  
I. Zavaliy ◽  
...  
Keyword(s):  
Hydrogen Generation ◽  
Strong Acid ◽  
Magnesium Hydride ◽  
Hydrolysis Reaction ◽  
Hydrolysis Rate ◽  
Reaction Yield ◽  
Buffer Solution ◽  
Passivation Film ◽  
Products Of Reaction ◽  
Hydrolysis Of

Magnesium hydride (MgH2) has a high hydrogen storage capacity (7.6 wt%) and the Mg element is abundant on the earth. Due to its strong reduction ability, even at room temperature it can provide the hydrogen yield reaching 15.2 wt% H (1703 mL/g) when interacting with water, which makes it very attractive for the application in supplying hydrogen for autonomous H energy systems. However, the hydrolysis reaction is rapidly inhibited by the Mg(OH)2 passivation layer formed on the surface of MgH2. In order to remove the passivation film and improve the efficiency of the MgH2 hydrolysis process, several methods including alloying, ball milling, changing the aqueous solution, have been successfully utilized. In this paper the process of hydrolysis of magnesium hydride in aqueous solutions of MgCl2 used as a promotor of the interaction has been studied in detail. It was found that the initial hydrolysis rate, pH of the reaction mixture, and overall reaction yield are all linearly dependent of the logarithm of MgCl2 concentration. It has been shown that pH of the reaction mixture in the presence of MgCl2 is well described by considering a system “weak base and its salt with strong acid” type buffer solution. Reference data for this hydrolysis reaction were also carefully analyzed. The mechanism and the kinetic model of the process of MgH2 hydrolysis in water solutions involved passivation of the MgH2 surface by the formed Mg(OH)2 precipitate followed by its repassivation have been proposed. The obtained after the hydrolysis reactions precipitates were studied using XRD and EDS. It was found also that the final products of reaction consist of Mg(OH)2 (brucsite type) and remaining MgH2. This fact shows that the formation of solid species such as MgCl2 xMgO yH2O at the studied conditions is unlikely and decreasing of pH the reaction mixture has a different nature.

Accelerated Hydrolysis of Solid-state NaBH4/Al System by Co2B Milled with Li for Hydrogen Generation

2016 ◽  
Vol 19 (2) ◽  
pp. 109-115
Author(s):  
Jiasong Chang ◽  
Wenlong Song ◽  
Ting Li ◽  
Jindan Chen ◽  
Hanmei Wu ◽  
...  
Keyword(s):  
Milling Time ◽  
Hydrogen Generation ◽  
Synergetic Effect ◽  
Hydrogen Yield ◽  
Preparation Process ◽  
Preparation Technology ◽  
High Hydrogen ◽  
Hydrolysis Process ◽  
Hydrolysis Of ◽  
Li Content

Co2B catalyst was milled with Al and Li to form Al-Li-Co2B composite, and the hydrogen generation performance of Al-Li-Co2B/NaBH4 system was investigated in this study. 100% hydrogen yield was reached, and high hydrogen generation rate was regulated by optimizing the composition design and preparation technology. The improvement was attributed to the synergetic effect of Co2B and Li in the preparation process, whereas a large specific surface area was obtained with the increase in Li content, Co2B, and milling time. In addition, the catalytic activity of Co2B and LiOH from Li hydrolysis was heightened for the hydrolysis of the Al/NaBH4 system because of the addition of Al(OH)3, LiAl2(OH)7.xH2O, and NaBO2 in the hydrolysis process.

Combined Hydrogen Generation from Al/NiCl2 Powder and Alkaline NaBH4 Solution for Portable Fuel Cell

2012 ◽  
Vol 16 (1) ◽  
pp. 9-12
Author(s):  
Yan Ling An ◽  
Chao Li ◽  
Bin Hong Tang ◽  
Xia Xiao ◽  
Tian Zhe Zhang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Catalytic Effect ◽  
Hydrogen Generation ◽  
Generation Rate ◽  
Hydrogen Yield ◽  
High Hydrogen ◽  
Composition Design ◽  
Naoh Solution ◽  
Al Powder ◽  
Hydrolysis Of

Hydrolysis of Al and NaBH4 for hydrogen generation has obtained considerable attention as a portable hydrogen source system. In this paper, we report a new combined hydrogen generation from Al powder and alkaline NaBH4 solution activated by NiCl2 additive. The system is characterized as the followed features: the interaction of Al/NaBH4 hydrolysis, catalytic effect of Ni2B for Al and NaBH4, Al hydrolysis stimulated by NaOH solution. The effects which affect the hydrogen generation performance of the system were studied. The results showed that a favorable combination of high hydrogen yield and high hydrogen generation rate might be obtained via the optimized composition design. Therefore, the system may be developed as a portable hydrogen source system.

Improved Commercialized Lithium Titanate Performance in Lithium-ion Batteries by Annealing

2012 ◽  
Vol 16 (1) ◽  
pp. 19-23
Author(s):  
Xinxi Li ◽  
Guoqing Zhang ◽  
Zhongqiong Xiong ◽  
Junqiao Xiong ◽  
Yongping Qiu
Keyword(s):  
Lithium Ion Batteries ◽  
Catalytic Effect ◽  
Hydrogen Generation ◽  
Lithium Ion ◽  
Lithium Titanate ◽  
Hydrogen Yield ◽  
High Hydrogen ◽  
Naoh Solution ◽  
Al Powder ◽  
Hydrolysis Of

Hydrolysis of Al and NaBH4 for hydrogen generation has obtained considerable attention as a portable hydrogen source system. In this paper, we report a new combined hydrogen generation from Al powder and alkaline NaBH4 solution activated by NiCl2 additive. The system is characterized as the followed features: the interaction of Al/NaBH4 hydrolysis, catalytic effect of Ni2B for Al and NaBH4, Al hydrolysis stimulated by NaOH solution. The effects which affect the hydrogen generation performance of the system were studied. The results showed that a favorable combination of high hydrogen yield and high hydrogen generation rate might be obtained via the optimized composition design. Therefore, the system may be developed as a portable hydrogen source system.

Hydrogen Generation from Hydrolysis of Sodium Borohydride Using Nanosized NiB Amorphous Alloy Catalysts

NANO ◽  
2020 ◽  
Vol 15 (06) ◽  
pp. 2050081
Author(s):  
Hongjing Yuan ◽  
Weitao Huo ◽  
Yongchao Hao ◽  
Yanna Wang ◽  
Weiye Qiao ◽  
...  
Keyword(s):  
Particle Size ◽  
Amorphous Alloy ◽  
Sodium Borohydride ◽  
Photoelectron Spectroscopy ◽  
Hydrogen Generation ◽  
Chemical Reduction ◽  
Catalytic Performance ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrolysis Of

Generation of hydrogen by sodium borohydride solution had attracted lots of attention. A serial of nanosized NiB catalysts were prepared using the chemical reduction method through introducing AlCl3 into the preparation. Catalytic performance of NiB catalysts were investigated in the hydrolysis of alkaline NaBH4 solution. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption, Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results showed that NiB catalysts possessed amorphous alloy structure, and the particle size could be adjusted by the AlCl3 amount. Catalytic performance showed that NiB catalyst with smaller particle size had much higher activity. The NiB catalyst also displayed high stability, the catalytic activity could retain about 84% of its initial value after four cycles.

Combination of Chemical Hydride Hydrogen Generation System with Low-Temperature PEMFCs

2012 ◽  
Vol 253-255 ◽  
pp. 751-759
Author(s):  
Ay Su ◽  
Hsiu Lu Chiang ◽  
Zhen Ming Huang
Keyword(s):  
Sodium Borohydride ◽  
High Purity ◽  
Production Efficiency ◽  
Hydrogen Generation ◽  
Flow Reactor ◽  
Integrated System ◽  
Hydrogen Yield ◽  
High Hydrogen ◽  
Fuel Feed ◽  
Hydrolysis Of

High purity hydrogen generated by hydrolysis of sodium borohydride can be used as the fuel of PEM fuel cell and other portable device. As its high hydrogen storage capacity, controllable reaction and mild condition, hydrogen generation by catalytic hydrolysis of chemical hydride, such as sodium borohydride, has been the major focus of researches. On the threshold of the controllable of hydrogen generated by hydrolysis of sodium borohydride, the catalyst for hydrolysis of hydrogen generation (HG) is studied. First, applying chemical plating, Ru/Ni foam catalyst was prepared; then, continuous flow reactor method was used to generate hydrogen. Varied parameters, such as concentrations of NaBH4 and NaOH, flow rate of NaBH4 solution and quantity of catalyst, were inspected in this research. It was found that, the NaBH4 and NaOH concentration at 20wt% and 3wt%, fuel feed to 4 g/min, hydrogen yield of 1.72 L/min, the hydrogen production efficiency as high as 91.2%. The present hydrogen generator was integrated with a 100W PEMFC and the optimum performance of the integrated system was studied. The hydrogen produced from NaBH4 has high purity and humidity; therefore, it can be directly used as the fuel for PEMFCs, which in general require humidified hydrogen. It is found that for cell voltage above 0.6V, the performance of cell using NaBH4 hydrogen is 103.45W, versus 99.9W with cylinder hydrogen.

Hydrolysis of AlLi/NaBH4 system promoted by Co powder with different particle size and amount as synergistic hydrogen generation for portable fuel cell

2013 ◽  
Vol 38 (25) ◽  
pp. 10857-10863 ◽  
Author(s):  
Mei Qiang Fan ◽  
Yu Wang ◽  
Guang Lei Tian ◽  
De sheng Mei ◽  
Da Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Fuel Cell ◽  
Hydrogen Generation ◽  
Hydrolysis Of

scholarly journals Immobilization of Pt nanoparticles on hydrolyzed polyacrylonitrile-based nanofiber paper

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soon Yeol Kwon ◽  
EunJu Ra ◽  
Dong Geon Jung ◽  
Seong Ho Kong
Keyword(s):  
Particle Size ◽  
Uniform Distribution ◽  
Pt Nanoparticles ◽  
Electrochemical Activity ◽  
Aggregate Formation ◽  
Free Standing ◽  
Pt Electrode ◽  
Catalytic Current ◽  
Nucleation Sites ◽  
Hydrolysis Of

AbstractThe electrochemical activity of catalysts strongly depends on the uniform distribution of monodisperse Pt nanoparticles without aggregates. Here, we propose a new hydrolysis-assisted smearing method for Pt loading on a free-standing paper-type electrode. Polyacrylonitrile (PAN)-based nanofiber paper was used as the electrode, and it acted as a Pt support. Hydrolysis of the electrode tripled the number of active nucleation sites for Pt adsorption on the PAN nanofibers, thereby significantly enhancing the wettability of the nanofibers. This facilitated the uniform distribution of Pt nanoparticles without aggregate formation up to 40 wt% (about 0.8 mg/cm2) with a particle size of about 3 nm. The catalytic current of the hydrolyzed Pt electrode in CH3OH/H2SO4 solution exceeded 213 mA/cm2 Pt mg, which was considerably greater than the current was 148 mA/cm2 Pt mg for an unhydrolyzed electrode.

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