Effect of potassium and water vapor on the catalytic reaction of nitric oxide and dioxygen over platinum

Autor:	S.S. Mulla, W. N. Delgass, Fabio H. Ribeiro, N. Chen, Lasitha Cumaranatunge, William S. Epling
Rok vydání:	2006
Předmět:	Order of reaction Transition metal chemistry Potassium Inorganic chemistry chemistry.chemical_element General Chemistry Rate equation Activation energy Platinum Heterogeneous catalysis Catalysis
Zdroj:	Catalysis Today. 114:57-63
ISSN:	0920-5861
Popis:	The turnover rate (TOR) per unit surface Pt atom for NO oxidation by O 2 on a Pt/K/Al 2 O 3 NO x storage-reduction catalyst was 2.5 times higher at 300 °C than the rate on a Pt/Al 2 O 3 catalyst with the same Pt loading. The power rate law orders with respect to NO, O 2 and NO 2 on the Pt/K/Al 2 O 3 catalyst were identical to those on Pt/Al 2 O 3 , viz. r = k [NO] 1 [O 2 ] 1 [NO 2 ] −1 , but the apparent activation energy obtained for the K-promoted catalyst was 60 kJ mol −1 , about 22 kJ mol −1 lower than on the Pt/Al 2 O 3 catalyst. The presence of water vapor in the feed resulted in an initial and irreversible decrease in the Pt surface area and NO conversion for both Pt/K/Al 2 O 3 and Pt/Al 2 O 3 catalysts, but no changes in the reaction orders or apparent activation energy were observed. Water did not affect the NO oxidation turnover rates.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::386b825cd55fc53dd01c5ec4a2f449d4 https://doi.org/10.1016/j.cattod.2006.02.013 Zobrazit plný text záznamu Full Text from ScienceDirect