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A Novel Self-Assembling Al-based Composite Powder with High Hydrogen Generation Efficiency.

Wang C, Liu Y, Liu H, Yang T, Chen X, Yang S, Liu X - Sci Rep (2015)

Bottom Line: The results indicated that the powders formed unique core/shell microstructures with cracked surfaces and (Bi, Sn)-rich phases distributed on the Al grain boundaries.The powders exhibited good oxidation resistance and reacted violently with distilled water at temperatures as low as 0 °C.The mechanisms of the hydrolysis reactions were also analyzed.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005, P. R. China.

ABSTRACT
In this study, a novel self-assembling hydrogen generation powder comprised of 80Al-10Bi-10Sn wt.% was prepared using the gas atomization method and then collected in an air environment. The morphological and hydrolysis properties of the powders were investigated. The results indicated that the powders formed unique core/shell microstructures with cracked surfaces and (Bi, Sn)-rich phases distributed on the Al grain boundaries. The powders exhibited good oxidation resistance and reacted violently with distilled water at temperatures as low as 0 °C. Furthermore, at 30 °C, the powders exhibited a hydrogen conversion yield of 91.30% within 16 minutes. The hydrogen produced by this powder could be directly used in proton exchange membrane fuel cells. The mechanisms of the hydrolysis reactions were also analyzed.

No MeSH data available.


(a) Hydrogen generation curves of the 80Al-10Bi-10Sn wt.% powders in distilled water; (b) XRD patterns of the powders after reacting with the distilled water at 30 °C for different amounts of time.
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f2: (a) Hydrogen generation curves of the 80Al-10Bi-10Sn wt.% powders in distilled water; (b) XRD patterns of the powders after reacting with the distilled water at 30 °C for different amounts of time.

Mentions: The hydrogen generation properties of the composite powders in distilled water were investigated and the results are shown in Fig. 2a. The 80Al-10Bi-10Sn powders exhibited superior hydrolysis characteristics and reacted immediately with distilled water. At 30 °C, the reactions occurred rapidly and the conversion yield increased to 91.30% within 16 minutes. Higher temperatures promoted the reactions, the reactions at 40 °C and 50 °C achieved higher conversion yields in smaller amounts of time. Even at 0 °C, the reactions were still violent, achieving a conversion yield of 80.43% after 88 minutes. The final conversion yield of the reactions at 0 °C, 30 °C, 40 °C and 50 °C is 80.56%, 92.02%, 94.05% and 97.15%, respectively. The reason for the conversion yield not reaching 100% is the unavoidable oxidation of the bare Al-phase on the powder surface during the powder collection process in air environment. Thus, a little amount of Al is consumed before the hydrogen generation experiments (Supplementary Figure S4). It is worth noting that, the conversion curve labeled with a pentagram in Fig. 2a represents the conversion curve of 80Al-10Bi-10Sn wt.% materials (with the same composition as that of the composite powders used in this study) prepared through the ball milling method in pure water at room temperature14. It is obvious that, although the self-assembling powders in this study were collected in an air environment, they exhibited relatively high hydrogen generation rates and conversion yields, indicating the composite powders in this study had good oxidation resistance and higher hydrogen generation efficiency. Prolonging the exposure time in air environment, the conversion yield of the composite powders almost kept the same value (Supplementary Figure S5).


A Novel Self-Assembling Al-based Composite Powder with High Hydrogen Generation Efficiency.

Wang C, Liu Y, Liu H, Yang T, Chen X, Yang S, Liu X - Sci Rep (2015)

(a) Hydrogen generation curves of the 80Al-10Bi-10Sn wt.% powders in distilled water; (b) XRD patterns of the powders after reacting with the distilled water at 30 °C for different amounts of time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663537&req=5

f2: (a) Hydrogen generation curves of the 80Al-10Bi-10Sn wt.% powders in distilled water; (b) XRD patterns of the powders after reacting with the distilled water at 30 °C for different amounts of time.
Mentions: The hydrogen generation properties of the composite powders in distilled water were investigated and the results are shown in Fig. 2a. The 80Al-10Bi-10Sn powders exhibited superior hydrolysis characteristics and reacted immediately with distilled water. At 30 °C, the reactions occurred rapidly and the conversion yield increased to 91.30% within 16 minutes. Higher temperatures promoted the reactions, the reactions at 40 °C and 50 °C achieved higher conversion yields in smaller amounts of time. Even at 0 °C, the reactions were still violent, achieving a conversion yield of 80.43% after 88 minutes. The final conversion yield of the reactions at 0 °C, 30 °C, 40 °C and 50 °C is 80.56%, 92.02%, 94.05% and 97.15%, respectively. The reason for the conversion yield not reaching 100% is the unavoidable oxidation of the bare Al-phase on the powder surface during the powder collection process in air environment. Thus, a little amount of Al is consumed before the hydrogen generation experiments (Supplementary Figure S4). It is worth noting that, the conversion curve labeled with a pentagram in Fig. 2a represents the conversion curve of 80Al-10Bi-10Sn wt.% materials (with the same composition as that of the composite powders used in this study) prepared through the ball milling method in pure water at room temperature14. It is obvious that, although the self-assembling powders in this study were collected in an air environment, they exhibited relatively high hydrogen generation rates and conversion yields, indicating the composite powders in this study had good oxidation resistance and higher hydrogen generation efficiency. Prolonging the exposure time in air environment, the conversion yield of the composite powders almost kept the same value (Supplementary Figure S5).

Bottom Line: The results indicated that the powders formed unique core/shell microstructures with cracked surfaces and (Bi, Sn)-rich phases distributed on the Al grain boundaries.The powders exhibited good oxidation resistance and reacted violently with distilled water at temperatures as low as 0 °C.The mechanisms of the hydrolysis reactions were also analyzed.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005, P. R. China.

ABSTRACT
In this study, a novel self-assembling hydrogen generation powder comprised of 80Al-10Bi-10Sn wt.% was prepared using the gas atomization method and then collected in an air environment. The morphological and hydrolysis properties of the powders were investigated. The results indicated that the powders formed unique core/shell microstructures with cracked surfaces and (Bi, Sn)-rich phases distributed on the Al grain boundaries. The powders exhibited good oxidation resistance and reacted violently with distilled water at temperatures as low as 0 °C. Furthermore, at 30 °C, the powders exhibited a hydrogen conversion yield of 91.30% within 16 minutes. The hydrogen produced by this powder could be directly used in proton exchange membrane fuel cells. The mechanisms of the hydrolysis reactions were also analyzed.

No MeSH data available.