Send to

Choose Destination
See comment in PubMed Commons below
J Phys Chem B. 2006 Jul 20;110(28):13897-904.

A DFT study of the adsorption and dissociation of CO on sulfur-precovered Fe100.

Author information

Schuit Institute of Catalysis, Technische Universiteit Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.


Sulfur is known to be a poison to several catalytic reactions, e.g., the Fischer-Tropsch synthesis (FTS), in which it affects drastically the performance of both iron- and cobalt-based catalysts. However, despite the importance of this industrial process, little is known about what elementary steps are poisoned by sulfur. In the present article, we report, using density functional theory, the effect of sulfur on one of the most relevant reactions in the FTS: the dissociation of carbon monoxide over iron surfaces. We have studied the adsorption and dissociation of CO on Fe(100)-S-p(2 x 2) (theta(S) = 0.25 ML) and on Fe(100)-S-c(2 x 2) (theta(S) = 0.50 ML). We have found surface configurations that correlate well with the desorption features observed in temperature-programmed desorption mass spectroscopy. In addition, we have calculated the activation energy of CO dissociation on Fe(100)-S-p(2 x 2), which, interestingly, is very similar to the activation energy of CO dissociation on the sulfur-free Fe(100) surface. However, the sign of the reaction changes by the presence of sulfur; CO dissociation is highly exothermic on the sulfur-free Fe(100) surface, whereas on the Fe(100)-S-p(2 x 2) surface, it is slightly endothermic. Moreover, according to our results, the influence of sulfur in the CO dissociation seems to be short-ranged.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Support Center