Title of article :
The effect of cerium, lanthanum and zirconium on nickel/alumina catalysts for the hydrogenation of carbon oxides
Author/Authors :
L. Znak، نويسنده , , K. Sto?ecki، نويسنده , , William J. Zielinski، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
Pages :
7
From page :
65
To page :
71
Abstract :
A series of nickel/alumina catalysts promoted with cerium, lanthanum and zirconium was studied in relation to CO and CO2 hydrogenation. The following examinations were applied in the studies: temperature-programmed reduction (TP reduction), X-ray diffraction, TP desorption of pre-adsorbed hydrogen, adsorption of O2 and its TP hydrogenation, thermal effect of O2 adsorption, adsorption of CO and its TP desorption or TP hydrogenation, and testing of activity in CO and CO2 hydrogenation. The examinations of O2 and CO adsorption demonstrate that the promoters decrease rate but do not affect quantity of the adsorption. On the other side, the promoters do not affect TP desorption of hydrogen and TP hydrogenation of pre-adsorbed oxygen which indicates that the promoters do not modify the state of oxygen and hydrogen adsorbed on nickel. At the same time, the TP desorption of CO demonstrates that, contrary to zirconium, cerium and lanthanum considerably promote dissociation of CO. The effect very likely is responsible for higher activity of the catalysts in TP hydrogenation of pre-adsorbed CO and also in the steady state activity of the catalysts in CO and CO2 hydrogenation.
Keywords :
lanthanum and zirconium promoters , Cerium , Hydrogenation of CO and CO2 , Nickel/alumina catalysts
Journal title :
CATALYSIS TODAY
Serial Year :
2005
Journal title :
CATALYSIS TODAY
Record number :
1234152
Link To Document :
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