低温甲烷氧化偶联Li-ZnO/La2O3催化剂

Abstract

采用浸渍法制备了Li-ZnO/La2O3催化剂并考察了其低温催化甲烷氧化偶联反应性能.反应条件下,在考察的w(Li)=2%和w(ZnO)=20%的Li-ZnO/La2O3在680℃得到了甲烷转化率为27.3%,C2选择性为65.2%,C2收率为17.8%的结果;在700℃,C2收率达到21.8%.Raman和XPS表征结果表明,催化剂低温催化性能与表面的活性吸附氧物种含量相关;La2O2CO3物种可能是提高催化剂的C2选择性的关键.

The oxidative coupling of methane (OCM) at low temperature was examined on Li-ZnO/La2O3 catalyst with w(Li)=2% and w(ZnO)=20%. CH4 conversion of 27.3% with C-2 selectivity of 65.2% was obtained at 680 degrees C and the C-2 yield reached 21.8% at 700 degrees C under reaction conditions. Raman and XPS results suggested that the low-temperature activity was related to the concentration of adsorbed oxygen species on the catalyst surface and La2O2CO3 was supposed to be responsible for the enhancement of C-2 selectivity in OCM.