TY - JOUR
T1 - Improving the stability of H-mordenite for n-butane isomerization
AU - Asuquo, R. A.
AU - Eder-Mirth, G.
AU - Seshan, K.
AU - Pieterse, J. A.Z.
AU - Lercher, J. A.
N1 - Funding Information:
The Christian Doppler Laboratories of Heterogeneous Catalysis and OMV are acknowledged for the financial support of this work. We are grateful the Japanese Catalysis Society for providing the mordenite sample.
PY - 1997
Y1 - 1997
N2 - The conversion of n-butane over mordenite-based catalysts in the presence of hydrogen and water was investigated for reaction temperatures between 523 and 623 K. Special attention was given to the influence of Pt upon catalytic activity, selectivity, and stability. With parent mordenite the catalytic activity for n-butane conversion decreased markedly after a short time on stream. Deactivation can be minimized by hydrogen (in the presence of Pt) and water addition. Both measures are thought to reduce the concentration of intermediate olefins in the zeolite pores. The best results with respect to selective conversion of n-butane to isobutane were obtained for 0.25 wt% Pt on mordenite in the presence of hydrogen. Higher concentrations of Pt in the catalyst are shown to be detrimental for n-butane isomerization, because of increasing selectivity to hydrogenolysis. A detailed mechanistic scheme for n-butane conversion over Pt-containing mordenites is presented. n-Butane conversion is concluded to occur via a bimolecular mechanism involving a complex network of hydrogen transfer, oligomerization/cracking, isomerization, hydrogenation/dehydrogenation, and hydrogenolysis.
AB - The conversion of n-butane over mordenite-based catalysts in the presence of hydrogen and water was investigated for reaction temperatures between 523 and 623 K. Special attention was given to the influence of Pt upon catalytic activity, selectivity, and stability. With parent mordenite the catalytic activity for n-butane conversion decreased markedly after a short time on stream. Deactivation can be minimized by hydrogen (in the presence of Pt) and water addition. Both measures are thought to reduce the concentration of intermediate olefins in the zeolite pores. The best results with respect to selective conversion of n-butane to isobutane were obtained for 0.25 wt% Pt on mordenite in the presence of hydrogen. Higher concentrations of Pt in the catalyst are shown to be detrimental for n-butane isomerization, because of increasing selectivity to hydrogenolysis. A detailed mechanistic scheme for n-butane conversion over Pt-containing mordenites is presented. n-Butane conversion is concluded to occur via a bimolecular mechanism involving a complex network of hydrogen transfer, oligomerization/cracking, isomerization, hydrogenation/dehydrogenation, and hydrogenolysis.
UR - http://www.scopus.com/inward/record.url?scp=0000851916&partnerID=8YFLogxK
U2 - 10.1006/jcat.1997.1655
DO - 10.1006/jcat.1997.1655
M3 - Article
AN - SCOPUS:0000851916
SN - 0021-9517
VL - 168
SP - 292
EP - 300
JO - Journal of Catalysis
JF - Journal of Catalysis
IS - 2
M1 - CA971655
ER -