Transition metal nanoparticles composite Al(OH)3 catalysts for hydrogen generation of Al/H2O system

Abstract

Background: Enhanced reaction of Al and water through catalysts is an excellent method for hydrogen generation. The generation of hydrogen is closely connected to the activity of catalysts. Methods: This work prepares a highly active metal-composite aluminum hydroxide (MCAH) catalyst by a simple co-precipitation method. The metallic nanoparticles are Ni, Co, and Ag. The MCAH catalyst exhibits a robust catalytic effect and significantly promotes the reaction of Al and water by decreasing the induction time. Characterization using powder X-ray diffraction, field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) adsorption analysis show that the metallic nanoparticles are attached to the surface of aluminum hydroxide, increasing the catalytic activity, which is considered to be assistant to the generation of hydrogen. Significant findings: The high catalytic activity could be due to the high specific surface area (such as Ni-Al(OH)3 for 144.1 m2/g) and stability. Furthermore, the dissociation of water molecules on the surface of the catalyst and the micro galvanic interaction between the metals and the Al(OH)3 could promote the hydration of the passive oxide layer on the surface of Al particles. Therefore, accelerate hydrogen generation.