FeCe nanocomposite with high iron content as efficient catalyst for generation of COx-free hydrogen via ammonia decomposition

Abstract

FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method. The as-prepared materials were characterized by various techniques including powder X-ray diffraction (XRD), N2 adsorption/desorption and high-resolution transmission electron microscopy (HRTEM). Catalyst with the highest iron content (90FeCe) shows the best activity for the hydrogen generation via ammonia decomposition. 83% NH3 conversion is achieved at 550 °C and nearly full conversion of NH3 is realized at 600 °C with a GHSV of 24000 cm3/(gcat·h). The large content and small size crystal particles of iron species are responsible for the good catalytic performance. Temperature-programmed reduction by hydrogen (H2-TPR) was performed to investigate the interaction between cerium and iron species. It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species, so as to improve the catalytic activity for ammonia decomposition.