fulltext.study @t Gmail

Carbon-supported cobalt–iron catalysts for ammonia synthesis

Paper ID Volume ID Publish Year Pages File Format Full-Text
44055 46001 2006 5 PDF Available
Carbon-supported cobalt–iron catalysts for ammonia synthesis

The cobalt, iron and Co–Fe catalysts deposited on carbon were prepared, characterised (XRD, H2 TPD) and studied in ammonia synthesis at 90 bar (H2:N2 = 3:1). Partly graphitised carbon material obtained via high temperature treatment (1900 °C) of commercial activated carbon was used as a support for the active metals (10 wt.%) and barium or potassium were used as promoters. XRD studies of unpromoted materials have shown that cobalt (5–20% in Co + Fe) dissolves in the iron phase (alloy formation); the average sizes of crystallites (20–30 nm) are roughly independent of the metal kind (Co, Fe, Co–Fe). The effect of Ba and that of K on the catalyst performance proved to be strongly dependent on the choice of an active phase (Co or Fe or Co–Fe). In the case of Co/C, the promotional effect of barium was extremely large. Furthermore, the Ba–Co/C system was found to be less inhibited by the ammonia product than Ba–Fe/C. At low temperature (400 °C) and at high conversion (8% NH3 in the gas), the surface-based reaction rate (TOF) for Ba–Co/C is about six times higher than that for Ba–Fe/C.

Ammonia synthesis; Cobalt–iron catalyst; Carbon support; Barium potassium promoter
First Page Preview
Carbon-supported cobalt–iron catalysts for ammonia synthesis
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 300, Issue 2, 26 January 2006, Pages 181–185
, , , , , , ,
Physical Sciences and Engineering Chemical Engineering Catalysis