Novel flame-retardant aluminum-based hydrolyzed material

Abstract

Al is the most abundant metallic element in the Earth's crust, and its theoretical capacity of hydrolyzing hydrogen production is high (1244mL/g). How to destroy Al2O3 films and control reaction rate are the key to control hydrolysis. Herein, we designed an activity-controlled and flame-retardant Al based hydrolytic composite by analyzing the mechanism of Al2O3 film breaking. The results show that the addition of anion is an important factor to improve film breaking. Among them, the system with CaH2 and NaF showed the best modification effect in deionized water (vmax = 265 mL/(s·g), Cmax = 1075 mL/g), and the mean hydrogen conversion was 97.79%. It is generally believed that the synergistic pitting effect of H− and F− is the heart of the continuation of the hydrolysis reaction. However, by studying the mechanism of pitting, we noticed that Ca(OH)2, Al(OH)3 and F− can provide an in-situ high concentration alkali field, which plays the crucial role for hydrolysis of Al. Meanwhile, the ignition test of the composite material shows that it is flame retardant. Then, the proposed novel hydrolysis film breaking mechanism of in-situ high concentration alkali field can also provide an idea for the further development of hydrolyzed hydrogen production materials.