(569fr) Effect of Citric Acid Addition on Co/Al2O3 Catalysts for Ammonia Decomposition

Ammonia has appeared as a promising medium for hydrogen due to its high hydrogen content, facile handling, and compability with existing infrastructure. The ammonia decomposition is an efficient way for generating CO_x-free hydrogen, with extensive research focus on Ruthenium, a costly noble metal. In this study, we prepared transition metal-based catalyst, Co/Al₂O₃. In order to improve the dispersion of Co particles on the Al₂O₃ support, we applied a citric acid-assisted impregnation method for preparation of catalyst (CA-Co/Al₂O₃). Sequential heat treatment of the CA-Co/Al₂O₃ under an inert gas atmosphere resulted in the formation of smaller Co particles, leading to a higher surface Co concentration compared to those of the counterpart prepared without citric acid. As a result of higher dispersion of Co particles, the CA-Co/Al₂O₃ catalyst exhibited superior performance to the Co/Al₂O₃ catalyst. Our results present a promising approach to enhance the performance of transition metal-based catalysts for ammonia decomposition.