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

Cuiping Wang,Xingjun Liu,Xinren Chen,Tao Yang,Yuheng Liu,Hongxin Liu,Shuiyuan Yang

doi:10.1038/srep17428

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.

Highlights

Due to increasing worldwide energy demands and environmental concerns, studies concerning the use of hydrogen (H2) as an energy source have become prevalent in the past few decades[1,2,3,4,5,6]
In order to reduce the energy of the whole powder, the (Bi, Sn)-rich phase with lower surface energies moved outward, wetting and occupying the powder surface
As for the small (Bi, Sn)-rich phases distributed on the grain boundaries inside the powders, as shown in Fig. 1c, they were supersaturated from the Al-rich phase when the temperature decreased

Summary

Introduction

Due to increasing worldwide energy demands and environmental concerns, studies concerning the use of hydrogen (H2) as an energy source have become prevalent in the past few decades[1,2,3,4,5,6]. Numerous attempts to remove this passive oxide layer and, thereby, improve the H2 generation efficiency of aluminum water reactions have been made[10,11,12,13] Among these existing strategies, the use of the ball milling method to fabricate Al-based powders containing low-melting-point metals[14,15,16], active metals[17,18,19], and other additives[20,21,22,23] has been considered to be the most effective way to facilitate the continuous generation of H2. The hydrogen generation properties and reaction mechanisms of this powder in distilled water were investigated

Methods

Results

Conclusion