Structure-function relationship for alumina supported platinum during formation of ammonia from nitrogen oxide and hydrogen in presence of oxygen
Journal article, 2016
We study the structure-function relationship of alumina supported platinum during forma- tion of ammonia from nitrogen oxide and dihydrogen by employing in situ X-ray absorption and Fourier transformed infrared spectroscopy. Particular focus is directed towards the effect of increased levels of oxygen on the reaction as a model system for emerging technologies for passive selective catalytic reduction of nitrogen oxides. The suppressed formation of ammo- nia observed as the feed becomes net-oxidizing is accompanied by a considerable increase in the oxidation state of platinum as well as enhanced formation of surface nitrates and loss of NH-containing surface species. In the presence of (excess) oxygen, the ammonia formation is proposed to be limited by the weak interaction between nitrogen oxide and the oxidized platinum surface. This leads to slow dissociation rate of nitrogen oxide and thus low abun- dance of atomic nitrogen surface species that can react with adsorbed hydrogen atoms. In this case the consumption of hydrogen through the competing water formation reaction and decomposition/oxidation of ammonia are of less importance for the net ammonia formation.
Author
Emma Adams
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Competence Centre for Catalysis (KCK)
Lindsay R. Merte
Lund University
Anders Hellman
Chalmers, Physics, Chemical Physics
Competence Centre for Catalysis (KCK)
Magnus Skoglundh
Competence Centre for Catalysis (KCK)
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Johan Gustafson
Lund University
Eva Benedixen
Haldor Topsoe
Pär Gabrielsson
Haldor Topsoe
Florian Bertram
Lund University
Jonas Evertsson
Lund University
Chu Zhang
Lund University
Stefan Carlson
Lund University
Per-Anders Carlsson
Competence Centre for Catalysis (KCK)
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Physical Chemistry Chemical Physics
1463-9076 (ISSN) 1463-9084 (eISSN)
Vol. 18 16 10850-10855High efficient Otto engine with diluted combustion II
Swedish Energy Agency (35561-2), 2015-01-01 -- 2017-12-31.
Time-resolved in situ methods for design of catalytic sites within sustainable chemistry
Swedish Research Council (VR) (2013-567), 2013-01-01 -- 2016-12-31.
Driving Forces
Sustainable development
Areas of Advance
Nanoscience and Nanotechnology
Transport
Energy
Materials Science
Subject Categories
Atom and Molecular Physics and Optics
Materials Chemistry
Condensed Matter Physics
DOI
10.1039/C5CP07624B