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Oxidation of NH[sub 3] over YBa[sub 2]Cu[sub 3]O[sub 7](123) oxide systems

Journal Article · · Journal of Catalysis; (United States)
;  [1]
  1. Indian Inst. of Science, Bangalore (India)
A temperature-programmed desorption study showed that the activation energy of oxygen desorption from YBa[sub 2]Cu[sub 3]O[sub 7[minus]x] (x = 0.05), PrBa[sub 2]Cu[sub 3]O[sub 7[minus]x] (x = 0.02), and YBa[sub 2]Cu[sub 2]CoO[sub 7+x] (x = 0.26) were 28.2, 26.4, and 22.3 kcal/mole, respectively. Anaerobic oxidation of NH[sub 3] over these oxide systems shows the formation of H[sub 2]O, N[sub 2], and NO transforming the oxides to tetragonal phases. Aerobic oxidation of NH[sub 3] is NO specific over all the three oxide catalysts. The Co-substituted YBa[sub 2]Cu[sub 2] CoO[sub 7+x] was the most reactive and stable oxide in this family; the lower oxygen desorption energy and higher reactivity are suggested to be due to the presence of holes in the form Co[sup 4+]O[sup 2[minus]] [r reversible] Co[sup 3+]O[sup [minus]]. The conversion of NH[sub 3] to NO was nearly 100% above 400 C when the ammonia flow rates were 10 [mu]mole/cm[sup 2]s over 0.3 g of the YBa[sub 2]Cu[sub 2]CoO[sub 7+x] catalyst.
OSTI ID:
7017439
Journal Information:
Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 135:2; ISSN 0021-9517; ISSN JCTLA5
Country of Publication:
United States
Language:
English

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