TY - JOUR
T1 - A priori catalytic activity correlations
T2 - The difficult case of hydrogen production from ammonia
AU - Ganley, J. C.
AU - Thomas, F. S.
AU - Seebauer, E. G.
AU - Masel, R. I.
N1 - Funding Information:
This work was supported by the Department of Defense Multidisciplinary University Research Initiative (MURI) program administered by the Army Research Office under Contract DAAD19-01-1-0582. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the Department of Defense or the Army Research Office.
PY - 2004/7
Y1 - 2004/7
N2 - The catalytic decomposition of ammonia has recently been proposed as a possible source of hydrogen for fuel cells. However, the ruthenium catalyst is costly. Although there exist several correlations for catalytic activity that suggest potentially useful alternatives, the particular candidates differ. The present work seeks to determine experimentally which, if any, of these correlations correctly predicts suitable substitutes. The experiments examine 13 different metallic catalysts from numerous places within the Periodic Table, and show that the activity varies in the order Ru > Ni > Rh > Co > Ir > Fe ≫ Pt > Cr > Pd > Cu ≫ Te, Se, Pb. The results suggest that nitrogen desorption limits the rate on Fe, Co, and Ni, whereas N-H bond scission limits the rate on other metals such as Rh, Ir, Pd, Pt, and Cu. Conventional single-parameter correlations of activity generally fail to predict the results because the rate-determining step changes across the data set.
AB - The catalytic decomposition of ammonia has recently been proposed as a possible source of hydrogen for fuel cells. However, the ruthenium catalyst is costly. Although there exist several correlations for catalytic activity that suggest potentially useful alternatives, the particular candidates differ. The present work seeks to determine experimentally which, if any, of these correlations correctly predicts suitable substitutes. The experiments examine 13 different metallic catalysts from numerous places within the Periodic Table, and show that the activity varies in the order Ru > Ni > Rh > Co > Ir > Fe ≫ Pt > Cr > Pd > Cu ≫ Te, Se, Pb. The results suggest that nitrogen desorption limits the rate on Fe, Co, and Ni, whereas N-H bond scission limits the rate on other metals such as Rh, Ir, Pd, Pt, and Cu. Conventional single-parameter correlations of activity generally fail to predict the results because the rate-determining step changes across the data set.
KW - Decomposition of ammonia
KW - Hydrogen from ammonia
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U2 - 10.1023/B:CATL.0000030108.50691.d4
DO - 10.1023/B:CATL.0000030108.50691.d4
M3 - Article
AN - SCOPUS:3042721539
SN - 1011-372X
VL - 96
SP - 117
EP - 122
JO - Catalysis Letters
JF - Catalysis Letters
IS - 3-4
ER -