High surface area Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} and Ce_0.9Mn_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} solid solutions for CO and HCHO oxidation

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="chmetcnv"> Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} and Ce_0.9Mn_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} solid solutions with high surface area (> 100 m² g^-1) have been prepared by a modified citrate sol-gel method. XRD results confirm the formation of Ce_0.9X_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} (where X = Cu or Mn) solid solution. Raman results indicate that a higher concentration of oxygen vacancies is obtained on the Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} catalyst compared to that of Ce_0.9Mn_0.1O_2-_{<img src='/image/spc_char/delta1.gif'>}. <i style="">In situ</i> DRIFTS results show the chemisorption of CO on the Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} catalyst, but there is no chemisorption of CO on the Ce_0.9Mn_0.1O_2-_{<img src='/image/spc_char/delta1.gif'>} catalyst. For CO oxidation, Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>} shows higher activity than Ce_0.9Mn_0.1O_2-_{<img src='/image/spc_char/delta1.gif'>}, due to the higher concentration of oxygen vacancies and the strong chemisorption of CO on the catalyst. For HCHO oxidation, Ce_0.9Mn_0.1O_2-_{<img src='/image/spc_char/delta1.gif'>} shows slightly higher activity than Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>}, due to the fact that the lattice oxygen is more easily reducible in Ce_0.9Mn_0.1O_2-_{<img src='/image/spc_char/delta1.gif'>} than in Ce_0.9Cu_0.1O_{2-<img src='/image/spc_char/delta1.gif'>}. </smarttagtype>