Resonant Active Sites in Catalytic Ammonia Synthesis: A Structural Model Full article
| Journal |
Surface Science
ISSN: 0039-6028 |
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| Output data | Year: 2016, Volume: 645, Number: 1, Pages: 41-48 Pages count : 8 DOI: 10.1016/j.susc.2015.10.042 | ||
| Tags | Active site, Basal plane, Catalytic ammonia synthesis, Noble metal, Semi-empirical calculation, Transition metal | ||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 14-03-00285 |
Abstract:
Adsorption sites Mn consisted of n adjacent atoms M, each bound to the adsorbed species, are considered within a
realistic model. The sum of bonds Σ lost by atoms in a site in comparison with the bulk atoms was used for evaluation
of the local surface imperfection, while the reaction enthalpy at that site was used as a measure of activity.
The comparative study of Mn sites (n = 1–5) at basal planes of Pt, Rh, Ir, Fe, Re and Ru with respect to heat of N2
dissociative adsorption QN and heat of Nad + Had → NHad reaction QNH was performed using semi-empirical
calculations. Linear QN(Σ) increase and QNH(Σ) decrease allowed to specify the resonant Σ for each surface in
catalytic ammonia synthesis at equilibrium Nad coverage. Optimal Σ are realizable for Ru2, Re2 and Ir4
only, whereas other centers meet steric inhibition or unreal crystal structure. Relative activity of the most
active sites in proportion 5.0 × 10−5: 4.5 × 10−3: 1: 2.5: 3.0: 1080: 2270 for a sequence of Pt4, Rh4, Fe4(fcc),
Ir4, Fe2–5(bcc), Ru2, Re2, respectively, is in agreement with relevant experimental data. Similar approach can be
applied to other adsorption or catalytic processes exhibiting structure sensitivity.
Cite:
Cholach A.R.
, Bryliakova A.A.
, Matveev A.V.
, Bulgakov N.N.
Resonant Active Sites in Catalytic Ammonia Synthesis: A Structural Model
Surface Science. 2016. V.645. N1. P.41-48. DOI: 10.1016/j.susc.2015.10.042 WOS Scopus РИНЦ ANCAN OpenAlex
Resonant Active Sites in Catalytic Ammonia Synthesis: A Structural Model
Surface Science. 2016. V.645. N1. P.41-48. DOI: 10.1016/j.susc.2015.10.042 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jul 13, 2015 |
| Accepted: | Oct 27, 2015 |
| Published online: | Nov 3, 2015 |
| Published print: | Mar 1, 2016 |
Identifiers:
| Web of science: | WOS:000368864700006 |
| Scopus: | 2-s2.0-84948181925 |
| Elibrary: | 24935115 |
| Chemical Abstracts: | 2015:1795297 |
| Chemical Abstracts (print): | 164:92618 |
| OpenAlex: | W2192687644 |