Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics

Details Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics

2003-05-14

arxiv.org/abs/cond-mat/0305312v1

Phys. Rev. B 68, 165412 (2003)

Physics

Condensed Matter

Materials Science

15 pages including 9 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.html

Scientific paper

10.1103/PhysRevB.68.165412

To help understand the high activity of silver as an oxidation catalyst, e.g., for the oxidation of ethylene to epoxide and the dehydrogenation of methanol to formaldehyde, the interaction and stability of oxygen species at the Ag(111) surface has been studied for a wide range of coverages. Through calculation of the free energy, as obtained from density-functional theory and taking into account the temperature and pressure via the oxygen chemical potential, we obtain the phase diagram of O/Ag(111). Our results reveal that a thin surface-oxide structure is most stable for the temperature and pressure range of ethylene epoxidation and we propose it (and possibly other similar structures) contains the species actuating the catalysis. For higher temperatures, low coverages of chemisorbed oxygen are most stable, which could also play a role in oxidation reactions. For temperatures greater than about 775 K there are no stable oxygen species, except for the possibility of O atoms adsorbed at under-coordinated surface sites Our calculations rule out thicker oxide-like structures, as well as bulk dissolved oxygen and molecular ozone-like species, as playing a role in the oxidation reactions.

Affiliated with

Also associated with

No associations

Rating

Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-80707