Simultaneous removal of N2O and CH4 as the strong greenhouse-effect gases over Fe-BEA zeolite in the presence of excess O2

• Published in: Catalysis letters 2000-11, Vol.69 (3-4), p.169-173
• Main Authors: KAMEOKA, S, KITA, K, TAKEDA, T, TANAKA, S, ITO, S, YUZAKI, K, MIYADERA, T, KUNIMORI, K
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Greenhouse effect; Greenhouse gases; High temperature; Methane; Nitrous oxide; Oxidation; Selective catalytic reduction; Stoichiometry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolites
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1023/a:1019054930595

Simultaneous catalytic removal of N2O and CH4 as the strong greenhouse‐effect gases was found to be possible over an Fe‐ion‐exchanged BEA zeolite (Fe‐BEA) by the selective catalytic reduction (SCR) of N2O with CH4. The direct decomposition of N2O (2N2O → 2N2 + O2) and the oxidation of CH4 (CH4 + 2O2 → CO2 + 2H2O) over Fe‐BEA zeolite required high temperature above 400 and 450 °C, respectively. Nevertheless, the catalytic reduction of N2O by adding CH4 over Fe‐BEA zeolite readily occurred at much lower temperatures (ca. 250–350 °C) whether in the presence of O2 or not. No oxidation of CH4 by O2 took place at these temperatures. On the basis of these results and the kinetic studies, it was concluded that CH4 reacted selectively with N2O to produce N2, CO2 and H2O over Fe‐BEA zeolite even in the presence of excess O2. Overall stoichiometry of the SCR of N2O with CH4 was determined as follows: 4N2O + CH4 → 4N2 + CO2 + 2H2O.