Synthesis and characterization of nano iron nitride for application in hydrazine decomposition

A series of nano iron nitrides were prepared from different nano iron oxides by a temperature-programmed reaction (TPR) method. It was found that the nano iron oxide prepared from homogeneous precipitation could yield 50~100 nm iron nitride. However, those prepared from the precipitation by ammonia or sol-gel method apparently produced larger nitride particles, even though they had much smaller original sizes. This suggests that nano iron oxide particles tend to congregate during the TPR process. In addition, the ?phase nano iron oxide particles were more likely to assemble than the ?phase iron oxide particles. They enlarged to 50 folds of the original size after the nitridation. The as-prepared nano iron nitrides were tested in the catalytic hydrazine decomposition, and they showed superior catalytic activities and much higher H2 selectivities than the large particle iron nitrides. The noble-metal-like characteristics of the nitrides are responsible for the high catalytic performance