TY - JOUR
T1 - Characterization of metallic species on Ni- And Co-containing ZSM-5 catalysts - reduction behavior and catalytic properties
AU - Jentys, A.
N1 - Funding Information:
The work was supported by the “Jubil%umsstiftung der Osterreichischen Nationalbank” project JF5410 and by the “Fonds zur Fdrderung der Wissenschaftlichen For-schung” under project P11479. We would like thank
PY - 1997
Y1 - 1997
N2 - A series of Co- and Ni-containing ZSM-5 zeolites with varying metal loading was prepared by solid-state ion exchange and by wet impregnation. Solid-state ion exchange led to highly dispersed metal ions inside the channels of ZSM-5. For the impregnated samples metal oxide clusters, mainly located on the exterior of the crystallites, were observed. Reduction at 573 K of NiZSM-5 prepared by solid-state ion exchange led to the formation of small metallic clusters inside the pores, whereas reduction at 773 K led to the formation of large Ni clusters outside the channels. CoZSM-5 could be only reduced at 773 K, where larger particles were rapidly formed. After low-temperature reduction, NiHZSM-5 showed in the hydroconversion of n-heptane an enhanced selectivity for isomerization, and after high-temperature reduction, for hydrocracking reactions. On CoHZSM-5 increased metal loading led to an extended hydrogenolysis activity in the hydroconversion of n-heptane.
AB - A series of Co- and Ni-containing ZSM-5 zeolites with varying metal loading was prepared by solid-state ion exchange and by wet impregnation. Solid-state ion exchange led to highly dispersed metal ions inside the channels of ZSM-5. For the impregnated samples metal oxide clusters, mainly located on the exterior of the crystallites, were observed. Reduction at 573 K of NiZSM-5 prepared by solid-state ion exchange led to the formation of small metallic clusters inside the pores, whereas reduction at 773 K led to the formation of large Ni clusters outside the channels. CoZSM-5 could be only reduced at 773 K, where larger particles were rapidly formed. After low-temperature reduction, NiHZSM-5 showed in the hydroconversion of n-heptane an enhanced selectivity for isomerization, and after high-temperature reduction, for hydrocracking reactions. On CoHZSM-5 increased metal loading led to an extended hydrogenolysis activity in the hydroconversion of n-heptane.
KW - CoZSM-5
KW - Metal clusters in ZSM-5
KW - NiZSM-5
KW - Reduction
KW - n-heptane hydroconversion
UR - http://www.scopus.com/inward/record.url?scp=0042484743&partnerID=8YFLogxK
U2 - 10.1016/S0144-2449(97)00030-4
DO - 10.1016/S0144-2449(97)00030-4
M3 - Article
AN - SCOPUS:0042484743
SN - 0144-2449
VL - 18
SP - 391
EP - 397
JO - Zeolites
JF - Zeolites
IS - 5-6
ER -