Ammonia formation over supported platinum and palladium catalysts
Artikel i vetenskaplig tidskrift, 2015

We report experimental results for the formation of ammonia from nitric oxide and hydrogen, and from nitric oxide, water and carbon monoxide over silica, alumina and titania supported platinum and palladium catalysts. Temperature programmed reaction experiments in gas flow reactor show a considerable formation of ammonia in the temperature range 200-450 C, which is suppressed by the presence of excess oxygen. However, oxygen sweep experiments show that for the titania supported catalysts minor amounts of oxygen promotes the ammonia formation at low temperatures. In situ DRIFT spectroscopy measurements indicate that cyanate species on the support play an important role in the ammonia formation mechanism. This work shows that alumina supported palladium is a promising system for passive selective catalytic reduction applications, exhibiting low-temperature activity during the water-gas-shift assisted ammonia formation reaction. Conversely, titania supported samples are less active for ammonia formation as a result of the poor thermal stability of the titania support.

In situ DRIFT spectroscopy

NO(x)reduction

NH3 formation

Pd

Catalytic exhaust aftertreatment

Pt

Passive-SCR

Författare

Emma Adams

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Magnus Skoglundh

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Milica Folic

Haldor Topsoe

Eva Bendixen

Haldor Topsoe

Pär Gabrielsson

Haldor Topsoe

Per-Anders Carlsson

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Applied Catalysis B: Environmental

0926-3373 (ISSN) 1873-3883 (eISSN)

Vol. 165 10-19

Drivkrafter

Hållbar utveckling

Innovation och entreprenörskap

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Fysikalisk kemi

Kemiska processer

DOI

10.1016/j.apcatb.2014.09.064