Abstract
The performance of Ce-promoted and undoped 5Co-15Ni/Al2O 3 catalysts for the dry reforming of CH4 has been investigated in a fixed-bed reactor. Although addition of Ce (2.5 wt%) significantly reduced carbon deposition by up to 50%, there was neither marked improvement in CH4 reaction rate (<5% increase) nor a significant change in activation energy. The increased carbon resistance of the Ce-promoted catalyst was attributed to equilibrium between stable multiple oxidation states of the Ce ion during the reaction. TPR-TPO of used catalysts revealed the existence of two types of carbon species-reactive Cα which is easily gasified by H2 and also participates in redox reactions with cerium oxides, and a relatively non-reactive Cβ which is only removed by O2 and does not participate in the redox cycle. A dual-site Langmuir-Hinshelwood mechanism for the reaction was also proposed.
Original language | British English |
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Pages (from-to) | 221-226 |
Number of pages | 6 |
Journal | Catalysis Today |
Volume | 164 |
Issue number | 1 |
DOIs | |
State | Published - 30 Apr 2011 |
Keywords
- Cerium promoter
- CO reforming of CH
- Cobalt-nickel catalyst
- Kinetic analysis