TY - JOUR
T1 - High pressure ammonia decomposition on Ru-K/CaO catalysts
AU - Sayas, Salvador
AU - Morlanes, Natalia Sanchez
AU - Katikaneni, Sai P.
AU - Harale, Aadesh
AU - Solami, Bandar
AU - Gascon, Jorge
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: Saudi Aramco is gratefully acknowledged for financial support.
PY - 2020/6/29
Y1 - 2020/6/29
N2 - Potassium-promoted ruthenium supported on CaO is a very efficient catalyst for ammonia decomposition, surpassing the performance of other Ru-supported solids. At an optimum Ru loading of 3% wt, catalysts with a K/Ru atomic ratio of 0.9 showed the best catalytic performance under a wide range of operating conditions, P = 1-40 bar, T = 250-550 °C and WHSV = 9000-30 000 mL g-1 h-1. Although NH3 conversion levels decrease considerably upon increasing the reaction pressure (X550 °C, 40 bar = 0.8), high pressure ammonia decomposition offers the possibility of COx-free compressed hydrogen and hydrogen productivities and TOFs 40 times bigger than when applying atmospheric pressure. Extensive characterization by CO chemisorption and HR-TEM demonstrates that potassium promotion increases metal dispersion by decreasing the Ru particle size. Electronic effects derived from the close proximity between K and Ru result in a decrease in the reaction apparent activation energy, as shown by a detailed kinetic analysis.
AB - Potassium-promoted ruthenium supported on CaO is a very efficient catalyst for ammonia decomposition, surpassing the performance of other Ru-supported solids. At an optimum Ru loading of 3% wt, catalysts with a K/Ru atomic ratio of 0.9 showed the best catalytic performance under a wide range of operating conditions, P = 1-40 bar, T = 250-550 °C and WHSV = 9000-30 000 mL g-1 h-1. Although NH3 conversion levels decrease considerably upon increasing the reaction pressure (X550 °C, 40 bar = 0.8), high pressure ammonia decomposition offers the possibility of COx-free compressed hydrogen and hydrogen productivities and TOFs 40 times bigger than when applying atmospheric pressure. Extensive characterization by CO chemisorption and HR-TEM demonstrates that potassium promotion increases metal dispersion by decreasing the Ru particle size. Electronic effects derived from the close proximity between K and Ru result in a decrease in the reaction apparent activation energy, as shown by a detailed kinetic analysis.
UR - http://hdl.handle.net/10754/664971
UR - http://xlink.rsc.org/?DOI=D0CY00686F
UR - http://www.scopus.com/inward/record.url?scp=85089704806&partnerID=8YFLogxK
U2 - 10.1039/d0cy00686f
DO - 10.1039/d0cy00686f
M3 - Article
SN - 2044-4761
VL - 10
SP - 5027
EP - 5035
JO - Catalysis Science and Technology
JF - Catalysis Science and Technology
IS - 15
ER -