Induced low temperature catalytic ignition by transient changes in the gas composition

• The effect of gas composition changes on the low temperature activity for supported platinum model catalysts has been studied. By introducing well-controlled periodic O2 pulses to a simple diluted gas mixture of CO and O2, a substantial improvement of the low temperature oxidation activity was observed. The reason for low activity on noble metals at low temperatures is often attributed to self-poisoning by CO. The improved catalytic performance observed is proposed to origin from the transients causing a surface reactant composition that is favourable for the reaction rate, i.e. lower degree of self-poisoning. This was also confirmed by in situ Fourier transform infrared spectroscopy in combination with mass spectrometry measurements, which gave evidence for the existence of a strong interplay between the gas phase concentration and the adsorbate composition for these catalysts.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

Nyckelord

cold start emissions

catalytic oxidation

platinum

DRIFT

carbon monoxide

self-poisoning

in situ FT-IR

low temperature activity

transient changes

periodic pulsing

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)