中国有色金属学报(英文版)

Trans. Nonferrous Met. Soc. China 22(2012) 1140-1145

Hydrogen generation from coupling reactions of AlLi/NaBH4 mixture in

water activated by Ni powder

LIU Shu, WANG Liang-liang, YAO Jun, SUN Wen-qiang, FAN Mei-qiang

Department of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, China

Received 6 May 2011; accepted 23 November 2011

Abstract:

A novel composition of AlLi/NaBH4 mixture activated by common Ni powder in water for hydrogen generation was investigated. The composition presents good hydrogen generation performance and an optimized Al-10% Li-10% Ni/NaBH4 mixture (mass ratio of 3:1) generates 1540 mL/g hydrogen with 96% efficiency at 333 K. Ni powder exhibits dual catalytic effects on the hydrolysis of AlLi/NaBH4 mixture due to the formation of Ni2B in the hydrolysis process. The Ni2B deposited on aluminum surface could act as a cathode of a micro galvanic couple. Ni2B/Al(OH)3 also has a synergistic effect on NaBH4 hydrolysis. Good hydrogen generation performance with stable pH value of hydrolysis byproduct Al(OH)3/NaBO2·2H2O was obtained with successive additions of Al-Li-Ni /NaBH4 mixture into fixed water.

Key words:

hydrogen generation; AlLi alloy; NaBH4; Ni;

1 Introduction

Hydrogen is an ideal energy source for fuel cells where the energy obtained in the reaction of hydrogen and oxygen is converted to electric energy. Hydrogen storage is still a large problem for the application of fuel cell in transportation vehicles and small portable devices [1,2]. Scientists have done much endeavor to solve the problem on two ways: one is to develop hydrogen storage materials which meet the required targets of U.S. Department of Energy (referred as DOE) at moderate pressure and temperature ranges [3]; another is to develop hydrogen generation materials which can supply portable hydrogen source when and where it is needed. Due to no hydrogen storage materials which can be efficiently applied to supplying hydrogen for fuel cells, on board hydrogen generation has been an alternative choice for fuel cells in recent years.

Sodium borohydride (NaBH4) has been extensively studied nowadays for portable and mobile fuel cell applications with theoretical gravimetric hydrogen generation value of 10.8% [3,4]. The environmentally benign sodium metaborate (NaBO2) can be recycled [5] and the hydrogen generation rate can be controlled with catalyst. Unfortunately, there are many engineering problems, such as high cost, low catalyst durability caused by the solubility limitations of sodium by-products borohydride and sodium metaborate (NaBO2) in an aqueous solution. Aluminum and aluminum alloy have been identified as another attractive candidate for on board hydrogen generation, with a lot of advantages including abundant source, low cost, etc [6]. Some studies [7-9] evidenced that Al has high reactivity in alkali solution. The corrosive nature of alkaline solutions is harmful to the common user; thus, they cannot be easily handled in practical applications. Many literatures have found that milled aluminum alloys including some additives such as light metals, salts and oxides, can react with water in neutral solution at mild condition [10,11]. But these additives would reduce the gravimetric hydrogen generation volume because they could not react with water. Previous work by LIU et al [12] showed that Li additive could significantly improve the hydrolysis rate of Al-based mixtures and increase hydrogen generation amount. It is a pity that the theoretical hydrogen generation density from Al/H2O system is limited to 3%-4% (mass fraction), which is still far below the target of 6.5% of the DOE [10,11,13]. Recently, SHAFIROVICH et al [14] found a novel method to supply about 7% hydrogen generation density from NaBH4/nano-Al composite. There was an interaction of Al/NaBH4 hydrolysis without any catalyst. The hydrolysis by-product Al(OH)3 from Al hydrolysis has a catalytic effect on the hydrolysis kinetic of NaBH4 [15]. On the contrary, a lot of heat and protons generated from NaBH4 hydrolysis also stimulate Al hydrolysis. Some non-ferrous metals or salts, such as Co, Ni, CoCl2 and NiCl2, have dual catalytic effects on the hydrolysis kinetic of Al/NaBH4. SOLER et al [8] found that AlCo/NaBH4 had better hydrolysis performance than Al/NaBH4. The improvement was attributed to the formation of Co2B in the hydrolysis process, which showed superior catalytic activity on the hydrolysis kinetic of Al/NaBH4. But so far, the hydrolysis of Al/NaBH4 system has to be performed in alkaline solution or using nanoscale Al powder.

In this work, a new composition of Al-Li-Ni and NaBH4 powder is designed to obtain high hydrogen generation density in neutral aqueous solution with affordable cost. The effects of composition design, preparation method and hydrolysis mechanism of Al/NaBH4 activated by Li and Ni, are explored and discussed. The aim of the work is to find the best composition with a high hydrogen yield and elaborate the possible application of AlLi/NaBH4 as hydrogen generation materials.

2 Experimental

2.1 Preparation of Al alloys

Aluminum powder (mean size of 10 μm, common grade, 99.9% purity) (supplied by Beijing Xingry Technology Company Ltd.), Li flakes (d16 mm×0.5 mm, 99.9% purity), pure Ni powder, sodium borohydride (solid, 95% purity) supplied by Tianjin Delan Chemical Company, China, were used as the starting materials. All reagents were used as-received. A little NaCl was added as a milling-assisted agent. The reagents were weighed and put into 50 mL stainless steel jars including stainless steel balls in an argon-filled glove box. The mass ratio ball to mixture was 26:1. Then 15 h-milling was performed in a QM-3SPO4 planetary ball miller at 450 r/min under 0.2 MPa argon atmospheres if not specially noted. Two preparation methods of Al-Li-Ni/NaBH4 mixture were considered: Method 1, mixture of Al+Li+Ni and NaBH4 was milled for 15 h; Method 2, Al-Li-Ni milled for 15 h and solid-state NaBH4 were mixed. The processes are listed in Fig. 1.

2.2 Measurement of hydrogen evolution

The hydrolysis experiments of Al-Li-Ni/NaBH4 mixtures were carried out in pure water with a sealed reactor attached a condenser at 333 K and 101.325 kPa. The volume of water was fixed (50 mL) and the mass of the Al-Li-Ni/NaBH4 mixture was probably 0.4 g. The mass ratio of Al-Li-Ni/NaBH4 mixture was 3:1, unless otherwise indicated. The mixture was pressed into a tablet in a stainless steel mold with diameter of 10 mm, using 49 kN pressure before the hydrolysis reaction because highly dispersed Al-Li alloy easily burned with water even at 298 K. The generated hydrogen gas was monitored by the measurement of the inverted cylinder by water displacement. The generated hydrogen was collected and measured from the water level change in the cylinder at 273 K and 101.325 kPa. The hydrogen generation rate was calculated from the amount evolved from the beginning of the test. As water/ (Al-Li-Ni/NaBH4 mixture) mass ratio was approximately 500: 1, the hydrolysis kinetics of aluminum mixture in water wholly came from the effect of global temperature.

2.3 Microstructure analysis

Powder X-ray diffraction (XRD) patterns of the as-prepared samples were collected by an X-ray diffractometer (RIGAKU, Japan, model, D/MAX2550V/PC) over a range of diffraction angle 2θ=10°-80° with Cu Kα radiation filtered by a monochromater. Scanning electron microscopy (SEM) observations were performed on a JSM-5610LV from JEOL Company. The solid hydrolysis by-product in the reactor was filtered using a vacuum pump and then dried in an oven at 323 K for 24 h.

Fig. 1 Flow chart of different preparation technologies of Al-Li-Ni/NaBH4 mixture: (a) Method 1; (b) Method 2

3 Results and discussion

3.1 Effects of preparation technology and Ni amount

Figure 2 shows hydrogen generation of Al-10%Li-10%Ni/NaBH4 (mass ratio of 3:1) by different preparation methods. The mixture prepared by Method 1 has bad hydrolysis performance with less than 800 mL/g hydrogen generation amount within 60 min. However, the mixture with the same composition prepared by Method 2 can generate approximately 1540 mL/g hydrogen within 60 min. NaBH4 milled with Al-Li-Ni or not seriously affects its hydrolysis performances due to the distribution of NaBH4 on the surface of Al-Li-Ni alloy. Figure 3 shows XRD patterns of Al-Li-Ni/NaBH4 by different preparation methods. Microstructure changes can be found with the addition of NaBH4. The peaks of Al, AlLi, etc, become broadened, reflecting that the particle size decreases. It can be further confirmed from SEM micrograph in Figs. 4(a) and 4(b). The NaBH4 particle deposited on the surface of the composites impedes the contact of Al, Ni and Li, and results in the uniform distribution of the composition. Large specific area and uniform distribution obtained with milled Al-Li-Ni /NaBH4 mixture results in fast hydrolysis rate in Fig. 2. Al-10% Li-10% Ni/NaBH4 mixture prepared by Method 1 has a maximum hydrogen generation rate of 667 mL/(g·min), evidently higher than 158 mL/(g·min) of the same mixture prepared by  Method 2.

From Fig. 3, there is also a great difference that the peaks of AlNi alloy cannot be identified in the XRD patterns of Al-Li-Ni/NaBH4 mixture prepared by Method 1, but observed in the mixture prepared by Method 2. AlNi alloy can easily form micro galvanic cell and react with water and NaBH4 to generate nano-Ni2B/Al(OH)3 catalyst due to the distribution of Ni into Al matrix in AlNi alloy. Figures 4(c) and 4(d) show SEM micrographs and EDS of hydrolysis byproduct of Al-Li-Ni/NaBH4 mixture prepared by Method 2. The sub-micro platy particles [LiAl2(OH)7] distribute in loose solid [Al(OH)3]. Combined with XRD results in Fig. 3 and Ni map in Fig. 4, it shows that Ni element is uniformly distributed in the hydrolysis by-product, reflecting that Ni2B is uniformly distributed in Al(OH)3. The same phenomenon was observed by SOLER et al [8] where AlCo/NaBH4 had good hydrogen generation performance due to the formation of nano-Co2B/Al(OH)3. But common Ni powder prepared by Method 1 has a low catalytic ability to improve hydrolysis of Al-Li-Ni/ NaBH4 mixture, even common Ni2B/Al(OH)3 generates in the hydrolysis process. Therefore, all Al-Li-Ni/NaBH4 mixtures are prepared according to Method 2 if not specially noted.

Fig. 2 Hydrogen generation of Al-10%Li-10%Ni/NaBH4 (mass ratio, 3:1) by different preparation methods: (a) Milled Al-Li-Ni/NaBH4 (mass ratio 3:1) by Method 1; (b) NaBH4+ milled Al-Li-Ni (mass ratio 3:1) by Method 2

Fig. 3 XRD patterns of Al-Li-Ni/NaBH4 with mass ratio of 3:1 by different preparation methods: (a) Al-10%Li- 10%Ni/NaBH4 mixture milled for 15 h; (b) Al-10%Li-10%Ni alloy milled for 15 h; (c) Solid hydrolysis product

Figure 5 shows the effect of Ni amount on hydrogen generation performance of Al-Li-Ni/NaBH4 mixture. Hydrogen generation amount increases from 1135 to 1540 mL/g with Ni amount increasing from 2% to 10% within 45 min. It has been elaborated that Ni has a dual catalytic effect on Al/NaBH4 mixture. So, more Ni amount results in higher hydrogen generation rate of the Al-Li-Ni/NaBH4 mixture, as shown in Fig. 5. However, with Ni amount further increasing from 10% to 15%, the hydrogen generation rate is increased when the sacrifice of hydrogen generation amount is decreased from 1540 to 1350 mL/g. Therefore, the suitable Ni amount in the mixture should be pursued.

3.2 Effect of Al-Li-Ni/NaBH4 mass ratio

Table 1 shows the maximum hydrogen generation rate and amount of Al-10%Li-10%Ni/NaBH4 mixture with different mass ratios. With Al-10%Li- 10%Ni/NaBH4 mass ratio changing from 4:0 to 0:4, the maximum hydrogen generation rate is decreased from 218 to 115 mL/(g·min). Hydrogen generation amount is increased from 843 to 1715 mL/g with Al-10%Li- 10%Ni/NaBH4 mass ratio changing from 0:4 to 1:3 and then is decreasing with further increased mass ratios. Their conversion efficiency was calculated and the largest value of 96% can be obtained in the mixture with Al-10%Li-10%Ni/NaBH4 in mass ratio of 3:1. The results confirm that the catalytic effect of Ni powder can be improved with the interaction of Al/NaBH4 hydrolysis. The hydrolysis of Al-Li-Ni is based on micro galvanic cell between Al (anode) and Ni (cathode). Li/NaBH4 hydrolysis generates a lot of protons and heat which stimulate the work of micro galvanic cell and accelerate Al corrosion. Otherwise, the exothermic reaction of Al and Li also improves NaBH4 hydrolysis with the catalytic effect of Ni2B/Al(OH)3. Considering hydrogen generation performance of Al-Li-Ni/NaBH4 mixture and high cost of NaBH4, Al-10%Li-10%Ni/NaBH4 mixture (mass ratio 3:1) may be a good choice for future portable hydrogen sources.

Fig. 4 SEM images (a, b, c) and EDS (d) of Al-10%Li-10%Ni/NaBH4: (a) SEM, milled Al-10%Li-10% Ni; (b) SEM, milled Al-10%Li-10%Ni with NaBH4; (c) SEM, hydrolysis by-product of NaBH4 and milled Al-10%Li-10% Ni; (d) EDS of hydrolysis by-product of NaBH4 and milled Al-10%Li-10% Ni

Fig. 5 Hydrogen generation performance of Al-10%Li/NaBH4 mixtures (mass ratio 3:1) doped with different Ni amounts

Table 1 Hydrogen generation amount and the maximum rate of Al-10%Li-10%Ni/NaBH4 with different mass ratios

3.3 Potential application

Table 2 and Fig. 6 report the hydrogen generation performance of the 11th successive addition of Al-10%Li-15%Ni/NaBH4 (mass ratio of 3:1) mixture into fixed water. The mixture has hydrogen generation amount of 1303 mL/g and the maximum hydrogen generation rate of 710 mL/(g·min-1) in the first run. The pH value of hydrolysis by-products quickly soars from 7 to 12.51. With the successive addition of Al-10%Li-15%Ni/NaBH4, the hydrogen generation performance of the mixture is improved evidently and the largest values of hydrogen generation amount and rate appear in the fifth addition. The values are 2359 mL/(g·min) and 1582 mL/g, respectively. The improvement has been explained from the catalytic effect of Ni2B/Al(OH)3 and the interaction of Al/NaBH4 hydrolysis. However, with further successive addition of Al-10%Li-15%Ni/NaBH4, hydrogen generation amount and rate are undermined. The mixture only yields 1321 mL/g hydrogen with a maximum hydrogen generation rate of 926 mL/(g·min) in the 11th addition, lower than those of the 5th addition. The hydrolysis by-product presents strong alkaline with pH of 12.5-13.5 which accelerates Al hydrolysis. So, the deteriorated hydrogen generation performance mostly comes from NaBH4 hydrolysis. Hydrolysis by-product NaBO2 indicates alkaline and dissolves Al(OH)3 in Reaction (1). Support failure of the catalyst results in the catalyst deterioration. The problem can be resolved by changing Al/NaBH4 mass ratio in practical application.

Al(OH)3+NaBO2→NaAlO2+H3BO3              (1)

Table 2 Hydrogen generation amount and the maximum rate of Al-10%Li-15%Ni/NaBH4 (mass ratio of 3:1) with consecutive runs

Fig. 6 Hydrogen generation of Al-10%Li-15%Ni/NaBH4 mixture (mass ratio of 3:1) in consecutive runs

4 Conclusions

1) The mixture of NaBH4 and milled Al-Li-Ni has excellent hydrogen generation performance and the optimized Al-10%Li-10%Ni/NaBH4 (mass ratio of 3:1) yields 1540 mL/g hydrogen with 96% efficiency at   333 K.

2) The effect of Ni powder is attributed to nano-Ni2B generated in the hydrolysis process due to the existence of AlNi alloy in milled Al-Li-Ni mixture. Ni2B has dual catalytic effects on the hydrolysis of AlLi/NaBH4 mixture. Ni2B deposited on aluminum surface can act as a cathode of a micro galvanic couple. Ni2B/Al(OH)3 catalyst is also a good promoter to improve the hydrolysis kinetics of NaBH4.

3) There exists the interaction of Al/NaBH4 hydrolysis while a lot of heat and protons from NaBH4 hydrolysis promote the corrosion of aluminum. On the contrary, the highly exothermic Al/H2O reaction and hydrolysis byproduct Al(OH)3 improve the hydrolysis performance of NaBH4.

4) Hydrolysis by-product shows good hydrogen generation performance with stable pH value when successive addition of Al-Li-Ni/NaBH4 mixture into fixed water is performed.

References

[1] Principi G, Agreste F, Magdalena A, Russo S L. The problem of solid state hydrogen storage [J]. Int J Hydrogen Energy, 2008, 34(12): 2087-2097.

[2] Parmuzina A V, Kravchenko O V. Activation of aluminum metal to evolve hydrogen from water [J]. Int J Hydrogen Energy, 2008, 33(12): 3073-3076.

[3] U.S. Department of Energy Hydrogen Program. Independent review: go/no-go recommendation for sodium borohydride for on-board vehicular hydrogen storage [EB/OL]. [2007]. NREL/MP-150-42220. http://www.hydrogen.energy,gov/.pdfs/42220.pdf.

[4] LiANG Yan, WANG Ping, DAI Hong-bin. Hydrogen generation from catalytic hydrolysis of sodium borohydride solution [J]. Progress in Chemistry, 2009, 21(10): 2219-2228. (in Chinese)

[5] ZHANG xiang, sun kui-bin, zhou jun-bo. progress in hydrogen production technology from hydrolysis of sodium borohydride [J]. Inorganic Chemicals Industry, 2010, 42(1): 9-12. (in Chinese)

[6] Charles S. Process of obtaining metals from their ores or compounds by electrolysis: US Patent 464933 [P]. 1883-02-23.

[7] Li Q F, Bjerrum N J. Aluminum as anode for energy storage and conversion: A review [J]. J Power Sources, 2002, 110(1): 1-10.

[8] Soler L, Macanas J, Munoz M. Synergistic hydrogen generation from aluminum, aluminum alloys and sodium borohydride in aqueous solutions [J]. Int J Hydrogen Energy, 2007, 32(18): 4702-4710.

[9] Uehara K, Takeshita H, Kotaka H. Hydrogen gas generation in the wet cutting of aluminum and its alloys [J]. J Mater Process Technol, 2002, 127(2): 174-177.

[10] Kravchenko O V, Semenenko K N, Bulychev B M, Kalmykov K B. Activation of aluminum metal and its reaction with water [J]. J Alloys Compounds, 2005, 397(1-2): 58-62.

[11] Czech E, Troczynski T. Hydrogen generation through massive corrosion of deformed aluminum in water [J]. Int J Hydrogen Energy, 2010, 35(3): 1029-1037.

[12] Liu S, FAN M Q, Wang C, Huang Y X, Chen D. Hydrogen generation by hydrolysis of Al-Li-Bi-NaCl mixture with pure water [J]. Int J Hydrogen Energy, 2012, 37(1): 1014-1020.

[13] Deng Z Y, Tang Y B, Zhu L L, Sakka Y, Ye J. Effect of different modification agents on hydrogen-generation by the reaction of Al with water [J]. Int J Hydrogen Energy, 2010, 35(18): 9561-9568.

[14] Shafirovich E, Diakov V, Varma A. Combustion of novel chemical mixtures for hydrogen generation [J]. Combust Flame, 2006, 144(1-2): 415-418.

[15] DAI H B, MA G L, KANG X D, WANG P. Hydrogen generation from coupling reactions of sodium borohydride and aluminum powder with aqueous solution of cobalt chloride [J]. Catalysis Today, 2011, 170: 50-55.

[16] Fan M Q, Xu F, Sun L X. Studies on hydrogen generation characteristics of hydrolysis of the ball milling Al-based materials in pure water [J]. Int J Hydrogen Energy, 2007, 32(14): 2809-2815.

金属Ni掺杂催化AlLi/NaBH4混合体系水解析氢

刘 姝,王亮亮,姚 钧,孙文强,范美强

中国计量学院 材料科学与工程学院,杭州 310018

摘  要:采用机械球磨法制备AlLi/NaBH4/Ni混合体系。水解测试分析表明,固态Al-Li-Ni/NaBH4混合物具有良好的析氢性能。Al-10%Li-10%Ni/NaBH4(质量比为3:1)混合物在333 K时的产氢值达1540 mL/g,产氢效率为96%。 通过XRD、SEM等分析Ni 掺杂改善其水解析氢机制,金属Ni 的产物Ni2B对Al合金和NaBH4的水解具有双重催化作用。Ni2B沉积在Al表面可作为微型腐蚀电池的阴极并促进铝的阳极腐蚀。另外,Ni2B/Al(OH)3对NaBH4的水解动力学具有很好的催化作用。连续水解测试结果显示:水解产物Al(OH)3/NaBO2·2H2O具有稳定的pH值,Al-Li-Ni /NaBH4混合物具有很好的水解动力学。

关键词:水解析氢;铝锂合金;硼氢化钠;镍

(Edited by YANG Hua)

Foundation item: Projects (21003112, 21003111) supported by the National Natural Science Foundation of China; Project (Y4090507) supported by the Zhejiang Basic Research Program, China

Corresponding author: FAN Mei-qiang; Tel: +86-571-86835738; E-mail: fanmeiqiang@126.com

DOI: 10.1016/S1003-6326(11)61296-X

Abstract: A novel composition of AlLi/NaBH4 mixture activated by common Ni powder in water for hydrogen generation was investigated. The composition presents good hydrogen generation performance and an optimized Al-10% Li-10% Ni/NaBH4 mixture (mass ratio of 3:1) generates 1540 mL/g hydrogen with 96% efficiency at 333 K. Ni powder exhibits dual catalytic effects on the hydrolysis of AlLi/NaBH4 mixture due to the formation of Ni2B in the hydrolysis process. The Ni2B deposited on aluminum surface could act as a cathode of a micro galvanic couple. Ni2B/Al(OH)3 also has a synergistic effect on NaBH4 hydrolysis. Good hydrogen generation performance with stable pH value of hydrolysis byproduct Al(OH)3/NaBO2·2H2O was obtained with successive additions of Al-Li-Ni /NaBH4 mixture into fixed water.

[1] Principi G, Agreste F, Magdalena A, Russo S L. The problem of solid state hydrogen storage [J]. Int J Hydrogen Energy, 2008, 34(12): 2087-2097.

[2] Parmuzina A V, Kravchenko O V. Activation of aluminum metal to evolve hydrogen from water [J]. Int J Hydrogen Energy, 2008, 33(12): 3073-3076.

[3] U.S. Department of Energy Hydrogen Program. Independent review: go/no-go recommendation for sodium borohydride for on-board vehicular hydrogen storage [EB/OL]. [2007]. NREL/MP-150-42220. http://www.hydrogen.energy,gov/.pdfs/42220.pdf.

[4] LiANG Yan, WANG Ping, DAI Hong-bin. Hydrogen generation from catalytic hydrolysis of sodium borohydride solution [J]. Progress in Chemistry, 2009, 21(10): 2219-2228. (in Chinese)

[5] ZHANG xiang, sun kui-bin, zhou jun-bo. progress in hydrogen production technology from hydrolysis of sodium borohydride [J]. Inorganic Chemicals Industry, 2010, 42(1): 9-12. (in Chinese)

[6] Charles S. Process of obtaining metals from their ores or compounds by electrolysis: US Patent 464933 [P]. 1883-02-23.

[7] Li Q F, Bjerrum N J. Aluminum as anode for energy storage and conversion: A review [J]. J Power Sources, 2002, 110(1): 1-10.

[8] Soler L, Macanas J, Munoz M. Synergistic hydrogen generation from aluminum, aluminum alloys and sodium borohydride in aqueous solutions [J]. Int J Hydrogen Energy, 2007, 32(18): 4702-4710.

[9] Uehara K, Takeshita H, Kotaka H. Hydrogen gas generation in the wet cutting of aluminum and its alloys [J]. J Mater Process Technol, 2002, 127(2): 174-177.

[10] Kravchenko O V, Semenenko K N, Bulychev B M, Kalmykov K B. Activation of aluminum metal and its reaction with water [J]. J Alloys Compounds, 2005, 397(1-2): 58-62.

[11] Czech E, Troczynski T. Hydrogen generation through massive corrosion of deformed aluminum in water [J]. Int J Hydrogen Energy, 2010, 35(3): 1029-1037.

[12] Liu S, FAN M Q, Wang C, Huang Y X, Chen D. Hydrogen generation by hydrolysis of Al-Li-Bi-NaCl mixture with pure water [J]. Int J Hydrogen Energy, 2012, 37(1): 1014-1020.

[13] Deng Z Y, Tang Y B, Zhu L L, Sakka Y, Ye J. Effect of different modification agents on hydrogen-generation by the reaction of Al with water [J]. Int J Hydrogen Energy, 2010, 35(18): 9561-9568.

[14] Shafirovich E, Diakov V, Varma A. Combustion of novel chemical mixtures for hydrogen generation [J]. Combust Flame, 2006, 144(1-2): 415-418.

[15] DAI H B, MA G L, KANG X D, WANG P. Hydrogen generation from coupling reactions of sodium borohydride and aluminum powder with aqueous solution of cobalt chloride [J]. Catalysis Today, 2011, 170: 50-55.

[16] Fan M Q, Xu F, Sun L X. Studies on hydrogen generation characteristics of hydrolysis of the ball milling Al-based materials in pure water [J]. Int J Hydrogen Energy, 2007, 32(14): 2809-2815.