Partial oxidation of methane to syngas over the catalyst derived from double perovskite (La0.5Sr0.5)2FeNiO6−δ

Double perovskite-type oxide (La0.5Sr0.5)2FeNiO6−δ (LSFN) was invented as the precursor of a catalyst for the partial oxidation of methane (POM). The catalyst derived from LSFN is the K2NiF4-supported Ni(0) system, where K2NiF4 denotes the oxide (La0.5Sr0.5)2Ni1−xFeO4+δ, a chemically stable structure with mixed ionic and electronic conducting properties. Among the four catalysts derived from LSFN, the best catalyst showed a high CH4 conversion (XCH4>99%XCH4>99%), high syngas selectivity (>98%) and, most importantly, nil coke formation at 900 °C. Detailed structural characterizations revealed that the presence of a small amount of SrCO3, left initially by incomplete formation of LSFN, and of nano-Ni(0) domains (or clusters <5 nm on average) on the K2NiF4 support is vital to this extraordinary catalytic performance. Furthermore, the decrease of H2/CO molar ratio with the increase in methane conversion happening in the course of activation was simulated using a group of the proposed key reaction steps of POM.

The bulk double perovskite oxide containing dispersed SrCO3 micro-phases is an unique precursor of the catalyst, K2NiF4-supported Ni(0) clusters, for partial oxidation of methane (POM). The catalyst, generated from treating the precursor in the feed stream of POM at 850 °C, demonstrates unusually strong coking resistance besides almost quantitative conversion of methane and very high selectivity to syngas.Figure optionsDownload as PowerPoint slide