Catalytic cycle of NO_x conversion based on pentacyanoferrate complexes

• Autorzy: Maciejowska I. , Stasicka Z.
• Języki publikacji: EN

Abstrakty

EN

Conversion of NO(x) + NH(3) to N(2), catalysed by the [Fe(II)(CN)(5)L]n- complexes (L= NO(+), NH(3), H(2)O proceeds through addition, comproportionation and substitution processes within the complexes and the reaction rates are sensitive to the different parameters. In this study the role of added cations was investigated and the main impact found concerned acceleration of the [Fe(CN)(5)NO](2)(2-) production from [Fe(CN)(5)L](3) (L= H(2)O, NH(3) and NO(2)(-) in alkaline medium. This could be achieved by increasing the amount ratio of [Fe(CN)(5)H(2)O] to its parent ammonia complex at given pH taking advantage from the specific cation effect on the rate of the [Fe(CN)(5)NH(3)](3) aquation. The rate wasaffected not only by concentration but also by the nature of the cation, i.e. by the hydratedradius of cation and its influence on the solution viscosity. The reaction of [Fe(CN)(5)NO](2-) with ammonia was re-examined in aspects of the pH dependent production of molecular nitrogen. The results are summarised in the overall photocatalytic cycle for which the optimal working pH range is limited to 10-11. The trend is consistent with the nucleophilic attack of NH(3)(+) on the N(NO) atom in [Fe(CN)(5)NO](2), followed by comproportionation within the N(NO)NH(+)(3) ligand, which results in N(2) generation.

Słowa kluczowe

EN

nitric oxide; pentacyanoferrates; cation effect; homogeneous catalysis

PL

tlenek azotu; żelazian; kation; kataliza homogeniczna

• Wydawca: Centrum Upowszechniania Nauki PAN
• Czasopismo: Bulletin of the Polish Academy of Sciences. Chemistry
• Rocznik: 2002
• Tom: Vol. 50, No. 1
• Strony: 67--76
• Opis fizyczny: Bibliogr. 40 poz.

Twórcy

autor

Maciejowska I.

autor

Stasicka Z.

• Department of Chemical Education, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland,