Perovskite catalysts for oxidative coupling of methane improved by Y‐doping

Abstract

Oxidative coupling of methane (OCM) is an effective route for methane direct conversion to ethylene. Perovskite oxides (ABO 3 ) with variable properties are potential catalysts for OCM by adjusting the compositions. In this study, four perovskite catalysts, BaMO 3-δ and BaM 1-x Y x O 3-δ (M = Zr, Ce; x = 0.2), were prepared by the sol-gel method to explore their catalytic performance of OCM.All catalysts are active toward OCM and reach the highest catalytic performance at 800 C. The OCM performance of Ce-based catalysts is higher than that of Zr-based catalysts. The selectivity of C 2 compounds is significantly improved by Y-doping. At CH 4 /O 2 mol ratio of 8, a C 2 selectivity of 67% was achieved on BaCe 0.8 Y 0.2 O 3-δ . Compared with Zr-based catalysts, more amounts of active oxygen species, which are beneficial to OCM, were observed on BaCeO 3-δ and BaCe 0.8 Y 0.2 O 3-δ . Meanwhile, higher contents of moderate and strong basic sites, which are beneficial to OCM, were found on the Y-doped catalysts. This is attributed to the generation of oxygen vacancies caused by Ydoping in the B-site. Therefore, BaCe 0.8 Y 0.2 O 3-δ with more active oxygen species and stronger basicity exhibits the highest performance among the four catalysts.

Diversity patterns and conservation gaps of Magnoliaceae species in China

“…Due to the high content of proanthocyanins, benzylisoquinoline and cyanogenic acid, many species have been used in traditional medicine for a long time (Schühly et al, 2011), such as Houpoëa officinalis, Yulania liliiflora, Michelia figo, Oyama sinensis, etc. (Pan et al, 2014;Wang et al, 2017). And some species, e.g., Magnolia grandiflora, and Michelia figo are essential components of lowland tropical and subtropical evergreen forests (Xia et al, 2008;Shen et al, 2018).…”

A-site defective La2−xCuO4 perovskite-type oxides for efficient oxidation of cyclohexylbenzene

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Carbon nanotube reinforced biobased poly(urethane urea) covalent adaptable network composite

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