Bimetal catalyst based on Fe and Co supported on Al pillared interlayer clays: Preparation, reactivity and mechanism for SCR-CH4
Shuying Ning, Shasha Huang, Honghai Yang, Bingtao Zhao, Yaxin Su
Abstract
Montmorillonite was used as raw clay to prepare the Al-pillared interlayer clay (Al-PILC) as support by impregnation methods. Co and Fe were loaded in series on Al-PILC to prepare the bimetal catalysts (Fe-Co/Al-PILC). The SCR-CH 4 was evaluated in a fixed bed reactor and the results indicated that 0.27Fe-Co/Al-PILC exhibited 100% N 2 selectivity and above 63% NO conversion in the presence of 10% H 2 O, and the introduction of Fe significantly improved the Co/Al-PILC catalyst's resistance to H 2 O and SO 2 . Characterization showed that Lewis and Brønsted acids co-existed on the catalyst surface, and the Lewis acid was the dominant active acid site and enhanced the activation of methane over the 0.27Fe-Co/Al-PILC. Fe promoted the formation of isolated Co 2+ and CoO species, and the isolated Fe 3+ particles improved CH 4 -SCR performance. The reaction route was proposed based on in situ DRIFTS tests and the active intermediates were mainly various nitrates and nitromethane (CH 3 NO 2 ).