Structure-function relationship for alumina supported platinum during formation of ammonia from nitrogen oxide and hydrogen in presence of oxygen
Artikel i vetenskaplig tidskrift, 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.
Författare
Emma Adams
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys
Lindsay R. Merte
Lunds universitet
Anders Hellman
Chalmers, Fysik, Kemisk fysik
Kompetenscentrum katalys
Magnus Skoglundh
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Johan Gustafson
Lunds universitet
Eva Benedixen
Haldor Topsoe
Pär Gabrielsson
Haldor Topsoe
Florian Bertram
Lunds universitet
Jonas Evertsson
Lunds universitet
Chu Zhang
Lunds universitet
Stefan Carlson
Lunds universitet
Per-Anders Carlsson
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Physical Chemistry Chemical Physics
1463-9076 (ISSN) 1463-9084 (eISSN)
Vol. 18 16 10850-10855Högeffektiv Ottomotor med utspädd förbränning II
Energimyndigheten (35561-2), 2015-01-01 -- 2017-12-31.
Tidsupplösta in situ metoder för design av katalytiska säten för hållbar kemi
Vetenskapsrådet (VR) (2013-567), 2013-01-01 -- 2016-12-31.
Drivkrafter
Hållbar utveckling
Styrkeområden
Nanovetenskap och nanoteknik
Transport
Energi
Materialvetenskap
Ämneskategorier
Atom- och molekylfysik och optik
Materialkemi
Den kondenserade materiens fysik
DOI
10.1039/C5CP07624B