TY - JOUR
T1 - Hydrogen production from ammonia decomposition using Co/γ-Al2O3 catalysts – Insights into the effect of synthetic method
AU - Bell, T. E.
AU - Ménard, H.
AU - González Carballo, J. M.
AU - Tooze, R.
AU - Torrente-Murciano, L.
PY - 2020/8/7
Y1 - 2020/8/7
N2 - Chemical hydrogen storage in molecules such as ammonia (>17 wt% H2) have the unique potential to overcome the current storage and transport limitations of the H2 economy. However, sustainable on-demand production of hydrogen via ammonia decomposition, requires the development of novel transition metal-based catalysts beyond the current use of highly active but expensive ruthenium to ensure economic feasibility. In this paper, we provide fundamental understanding of the effects of a range of synthetic methods of Co/γ-Al2O3 catalysts on the resulting ammonia decomposition activity. The main activity determining factors are collectively the reducibility of the cobalt species and their particle size. This systematic work demonstrates that decreasing the cobalt particle size enhances the ammonia decomposition catalytic activity. However, a careful balance is required between a strong metal-support interaction leading to small particle sizes (promoted by precipitation methods) and the formation of inactive cobalt aluminate species (encouraged by adsorption methods). In addition, impurities such as boron and chloride remaining from particular synthetic methods were found to have detrimental effects on the activity.
AB - Chemical hydrogen storage in molecules such as ammonia (>17 wt% H2) have the unique potential to overcome the current storage and transport limitations of the H2 economy. However, sustainable on-demand production of hydrogen via ammonia decomposition, requires the development of novel transition metal-based catalysts beyond the current use of highly active but expensive ruthenium to ensure economic feasibility. In this paper, we provide fundamental understanding of the effects of a range of synthetic methods of Co/γ-Al2O3 catalysts on the resulting ammonia decomposition activity. The main activity determining factors are collectively the reducibility of the cobalt species and their particle size. This systematic work demonstrates that decreasing the cobalt particle size enhances the ammonia decomposition catalytic activity. However, a careful balance is required between a strong metal-support interaction leading to small particle sizes (promoted by precipitation methods) and the formation of inactive cobalt aluminate species (encouraged by adsorption methods). In addition, impurities such as boron and chloride remaining from particular synthetic methods were found to have detrimental effects on the activity.
KW - Alumina
KW - Ammonia decomposition
KW - Cobalt
KW - Heterogeneous catalysis
KW - Hydrogen
KW - Synthesis method
UR - http://www.scopus.com/inward/record.url?scp=85089251860&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2020.07.090
DO - 10.1016/j.ijhydene.2020.07.090
M3 - Article
AN - SCOPUS:85089251860
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
SN - 0360-3199
ER -