A microkinetic model of ammonia decomposition on a Pt overlayer on Au(111)
- Author(s)
- Karsten Rasim, Manfred Bobeth, Wolfgang Pompe, Nicola Seriani
- Abstract
Ammonia decomposition is important for a series of technological applications. For developing efficient catalysts for this reaction, basic understanding of underlying mechanisms is fundamental. We have investigated ammonia decomposition on platinum (11 1) and (1 0 0) surfaces, and on a platinum overlayer on a (1 1 1) gold substrate within a microkinetic model. The kinetic parameters in the corresponding rate equations have been estimated on the basis of ab initio calculations of reaction and activation energies for the adsorption and dehydrogenation processes on the catalyst surface. Steady-state coverages of species participating in the decomposition have been determined as solution of the rate equations in the limiting case of small ammonia concentrations of an N-2-NH3 model gas mixture under flow conditions. Calculated turnover frequencies of ammonia decomposition as a function of the temperature reproduce characteristic features reported for platinum wires. The highest turnover frequency and hydrogen coverage have been obtained for the platinum overlayer on gold. Potential application of this system as ammonia-sensing device is discussed.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Technische Universität Dresden
- Journal
- Journal of Molecular Catalysis A: Chemical
- Volume
- 325
- Pages
- 15-24
- No. of pages
- 10
- ISSN
- 1381-1169
- DOI
- https://doi.org/10.1016/j.molcata.2010.03.021
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1030 Physics, Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/23423383-2fa8-43f3-8286-e6a808c31a8c