Experimental Study on Zn-Doped Al-Rich Alloys for Fast on-Board Hydrogen Production

Abstract

For the purpose of investigating the effect of Zn replacement of In3Sn on the hydrogen production performance of Al-rich alloy ingots, Al-Ga-In3Sn alloys with various Zn dosages (0–5 wt.%) were prepared by a traditional melting and casting technique. The phase compositions and microstructures were characterized using X-ray diffractometer (XRD) and scanning electron microscope (SEM) with an Energy Dispersed X-ray system (EDS). The SEM results indicate that, with a small amount of Zn instead of In3Sn, the number and total area of grain boundary (GB) phases will decrease gradually, and the average single GB area will eventually stabilize. The distribution of Zn in the alloy is similar to that of Ga, and an area with high Zn content appeared in the high-Zn-doped sample. The melting behaviors of Al with other metals were measured by DSC. The reaction of these alloys and water were investigated at different temperatures. Compared with Al-Ga-In3Sn alloy, low addition of Zn changed the composition of GB phase and increased the maximum hydrogen production rate. The reason for the changes in the hydrolysis reaction of Al with the addition of Zn was discussed.

Enhanced Hydrogen Generation through Low-Temperature Plasma Treatment of Waste Aluminum for Hydrolysis Reaction

“…However, a notable obstacle hindering the practical application of the aluminum hydrolysis process is the inert aluminum oxide layer that naturally forms on the surface of pure aluminum, impeding the hydrogen generation process. Various techniques have been examined to remove the passive oxide, including mechanical activation of Al [ 22 , 23 , 24 ], liquid metal activation and alloying [ 25 , 26 , 27 ], activation of Al in alkaline or acidic solutions [ 28 , 29 , 30 ], activation by Al 2 O 3 or Al(OH) 3 [ 31 , 32 , 33 ], activation with carbon-based materials [ 34 , 35 , 36 ], and others [ 37 , 38 , 39 , 40 ]. Significant improvements were achieved using these methods, mostly related to aluminum–water reaction kinetics.…”

Special Issue “Intermetallic Compound”

“…In the last article, Qian Gao et al [10] present an experimental study on Zn-doped Al-rich alloys for fast on-board hydrogen production. The hypothesis that Zn will change the hydrogen production performance of the alloy by entering the GB phase was verified and it was found that the reaction mechanism cannot only be explained by the eutectic reaction of the GB phase and Al.…”