The catalytic performance of oxidative coupling of methane(OCM) over Eu 2O 3 catalysts promoted by alkaline earth fluorides was studied The results showed that C 2 hydrocarbon selectivity and yield over the fluor...The catalytic performance of oxidative coupling of methane(OCM) over Eu 2O 3 catalysts promoted by alkaline earth fluorides was studied The results showed that C 2 hydrocarbon selectivity and yield over the fluoride promoted Eu 2O 3 catalysts were apparently higher than those over pure Eu 2O 3; the OCM performance increased according to the sequence of CaF 2 Eu 2O 3≈BaF 2 Eu 2O 3<SrF 2 Eu 2O 3 under the same conditions XRD experiment indicated that rhombohedral EuOF phase formed in the fresh BaF 2 Eu 2O 3 catalyst, while the exchange of F - and O 2- did not apparently happen in the fresh CaF 2 Eu 2O 3 and SrF 2 Eu 2O 3 catalysts Pyridine TPD and CO 2 TPD measurements found that, after adding SrF 2 to Eu 2O 3, the catalyst surface acidity decreased, whereas the surface basic strength increased slightly, resulting in an improvement in C 2 selectivity and yield展开更多
文摘The catalytic performance of oxidative coupling of methane(OCM) over Eu 2O 3 catalysts promoted by alkaline earth fluorides was studied The results showed that C 2 hydrocarbon selectivity and yield over the fluoride promoted Eu 2O 3 catalysts were apparently higher than those over pure Eu 2O 3; the OCM performance increased according to the sequence of CaF 2 Eu 2O 3≈BaF 2 Eu 2O 3<SrF 2 Eu 2O 3 under the same conditions XRD experiment indicated that rhombohedral EuOF phase formed in the fresh BaF 2 Eu 2O 3 catalyst, while the exchange of F - and O 2- did not apparently happen in the fresh CaF 2 Eu 2O 3 and SrF 2 Eu 2O 3 catalysts Pyridine TPD and CO 2 TPD measurements found that, after adding SrF 2 to Eu 2O 3, the catalyst surface acidity decreased, whereas the surface basic strength increased slightly, resulting in an improvement in C 2 selectivity and yield