Improved performance of hydrogen generation for Al–Bi-CNTs composite by spark plasma sintering

Abstract

A new preparing method for Al-based hydrogen generation material has been proposed in this work. Al–Bi-CNTs materials have been prepared by the method of combination of both ball milling and spark plasma sintering (SPS). After SPS, the Al–Bi-CNTs materials change from a powder into a block. The influence of SPS on hydrogen generation performance of Al–Bi-CNTs block has been studied. The results indicate that the performances of hydrogen generation and antioxidant capacity of the block are higher than those of the powder. The conversion yield of Al-3.0 wt% Bi-5.0 wt% CNTs block reaches to 94.5% at a reaction temperature 343.15 K. However, the corresponding conversion yield of powder is only 46.1% at the same condition. Meanwhile, the block also shows a good oxidation resistance, such as its conversion yield is 65.8% of its original value after being exposed in air for 20 days. The conversion yield of powder, however, only retains 11.1% of its original value. The activation mechanism of SPS on Al based composite is also studied by XRD, SEM and TEM. In a word, the Al–Bi-CNTs block prepared by SPS is a suitable material to generate hydrogen for fuel cells.