Insight into role of surface Sr‐sites in Sr/LOC‐HL catalyst for promoting low‐temperature oxidative coupling of methane

Abstract

AbstractA series of Sr‐modified hedgehog‐like La2O2CO3 (Sr/LOC‐HL) catalysts were synthesized by the two‐step methods of coordination polymer induced formation and incipient wetness impregnation. Sr/LOC‐HL catalysts show the uniform nanorod morphology with width of 180 nm. The strong interaction between SrOx species and La2O2CO3 boosts the formation of active oxygen species for enhancing CH4 activation at low temperature. Sr/LOC‐HL catalysts show excellent catalytic performances for oxidative coupling of methane into C2+ hydrocarbons at low temperature (<500°C), and the selectivity is strongly dependent on the strong surface basic sites induced by the SrOLa bond. The Sr10/LOC‐HL catalyst exhibits the best catalytic performance and stability for OCM reaction at low temperature, that is, its CH4 conversion, C2+ selectivity, and yield at 450°C is 20.3%, 69.1%, and 13.2%, respectively; and its catalytic activity maintains stable during 3000 min. Insight into role of surface Sr‐sites would further improve catalytic performance at low temperature.