TY - JOUR
T1 - The Effect of Phosphorus Exposure on Diesel Oxidation Catalysts - Part II: Structural Changes by Transmission Electron Microscopy
AU - Honkanen, Mari
AU - Kärkkäinen, Marja
AU - Heikkinen, O.
AU - Kallinen, K.
AU - Kolli, Tanja
AU - Huuhtanen, Mika
AU - Lahtinen, J.
AU - Keiski, Riitta L.
AU - Lepistö, Toivo
AU - Vippola, M.
PY - 2015
Y1 - 2015
N2 - Phosphorus poisoning and its effect on the diesel oxidation catalysts morphology was studied by transmission electron microscopy (TEM). The studied catalyst samples were PtPd or Pt supported on the aluminabased washcoat including additives. The laboratory-scale phosphorus exposures were carried out with two different phosphorus concentrations. The cross-sectional TEM samples were prepared from the fresh and phosphorustreated catalysts. After phosphorus exposures, significant structural changes were observed compared to the fresh catalysts. The shape of the noble metal particles had changed from irregular to more spherical-shaped particles. In addition, phosphorus was detected throughout the catalyst TEM samples but the amount varied depending on the local composition of the support. Phosphorus accumulated mainly in the alumina-containing areas of the support and indications of dense and amorphous aluminium phosphates were found. Based on the results gained, cross-sectional TEM characterization is essential to observe these kinds of morphological changes in the catalysts caused e.g. by phosphorus exposures. In addition, cross-sectional TEM samples are needed to study the effect of local variation in the support composition on the phosphorus accumulation.
AB - Phosphorus poisoning and its effect on the diesel oxidation catalysts morphology was studied by transmission electron microscopy (TEM). The studied catalyst samples were PtPd or Pt supported on the aluminabased washcoat including additives. The laboratory-scale phosphorus exposures were carried out with two different phosphorus concentrations. The cross-sectional TEM samples were prepared from the fresh and phosphorustreated catalysts. After phosphorus exposures, significant structural changes were observed compared to the fresh catalysts. The shape of the noble metal particles had changed from irregular to more spherical-shaped particles. In addition, phosphorus was detected throughout the catalyst TEM samples but the amount varied depending on the local composition of the support. Phosphorus accumulated mainly in the alumina-containing areas of the support and indications of dense and amorphous aluminium phosphates were found. Based on the results gained, cross-sectional TEM characterization is essential to observe these kinds of morphological changes in the catalysts caused e.g. by phosphorus exposures. In addition, cross-sectional TEM samples are needed to study the effect of local variation in the support composition on the phosphorus accumulation.
KW - diesel oxidation catalyst
KW - phosphorus poisoning
KW - structural characterization
KW - transmission electron microscopy
KW - diesel oxidation catalyst
KW - phosphorus poisoning
KW - structural characterization
KW - transmission electron microscopy
KW - diesel oxidation catalyst
KW - phosphorus poisoning
KW - structural characterization
KW - transmission electron microscopy
UR - http://link.springer.com/article/10.1007/s11244-015-0465-y
U2 - 10.1007/s11244-015-0465-y
DO - 10.1007/s11244-015-0465-y
M3 - Article
SN - 1022-5528
VL - 58
SP - 971
EP - 976
JO - Topics in Catalysis
JF - Topics in Catalysis
IS - 14-17
ER -